OMAKE(1)

NAME
omake is a build system designed to scale from small projects to very large projects spanning many directories. omake uses a syntax similar to make(1), with many additional features, including accurate automated dependency analysis based on MD5 digests.

DESCRIPTION

omake is designed for building projects that might have source files in several directories. Projects are normally specified using an OMakefile in each of the project directories, and an OMakeroot file in the root directory of the project. The OMakeroot file specifies general build rules, and the OMakefiles specify the build parameters specific to each of the subdirectories. When omake runs, it walks the configuration tree, evaluating rules from all of the OMakefiles. The project is then built from the entire collection of build rules.

  AUTOMATIC DEPENDENCY ANALYSIS

Dependency analysis has always been problematic with the make(1) program. omake addresses this by adding the .SCANNER target, which specifies a command to produce dependencies. For example, the following rule

    .SCANNER: %.o: %.c
        $(CC) $(INCLUDE) -MM $<

is the standard way to generate dependencies for .c files. omake will automatically run the scanner when it needs to determine dependencies for a file.

  CONTENT-BASED DEPENDENCY ANALYSIS

Dependency analysis in omake uses MD5 digests to determine whether files have changed. After each run, omake stores the dependency information in a file called .omakedb in the project root directory. When a rule is considered for execution, the command is not executed if the target, dependencies, and command sequence are unchanged since the last run of omake. As an optimization, omake does not recompute the digest for a file that has an unchanged modification time, size, and inode number.

See the following manual pages for more information.

omake-quickstart
     A quickstart guide to using omake.

omake-options
     Command-line options for omake.

omake-root
     The system OMakeroot contains the default specification of how to build C, OCaml, and LaTeXprograms.

omake-language
     The omake language, including a description of objects, expressions, and values.

omake-shell
     Using the omake shell for command-line interpretation.

omake-rules
     Using omake rules to build program.

omake-base
     Functions and variables in the core standard library.

omake-system
     Functions on files, input/output, and system commands.

omake-pervasives
     Pervasives defines the built-in objects.

osh
     The osh command-line interpreter.

omake-doc
     All the OMake documentation in a single page.

OMAKE QUICKSTART GUIDE

  FOR USERS ALREADY FAMILIAR WITH MAKE

For users already familiar with the make(1) command, here is a list of differences to keep in mind when using omake.

*   In omake, you are much less likely to define build rules of your own. The system provides many standard function (like StaticCLibrary and CProgram) to specify these builds more simply.

*   Implicit rules using .SUFFIXES and the .suf1.suf2: are not supported. You should use wildcard patterns instead %.suf2: %.suf1.

*   Scoping is significant: you should define variables and .PHONY targets before they are used.

*   Subdirectories are incorporated into a project using the .SUBDIRS: target.

  BUILDING A SMALL C PROGRAM

To start a new project, the easiest method is to change directories to the project root and use the command omake --install to install default OMakefiles.

    $ cd ~/newproject
    $ omake --install
    *** omake: creating OMakeroot
    *** omake: creating OMakefile
    *** omake: project files OMakefile and OMakeroot have been installed
    *** omake: you should edit these files before continuing

The default OMakefile contains sections for building C and OCaml programs. For now, we'll build a simple C project.

Suppose we have a C file called hello_code.c containing the following code:

    #include <stdio.h>
    int main(int argc, char **argv)
    {
        printf("Hello world\n");
        return 0;
    }

To build the program a program hello from this file, we can use the CProgram function. The OMakefile contains just one line that specifies that the program hello is to be built from the source code in the hello_code.c file (note that file suffixes are not passed to these functions).

    CProgram(hello, hello_code)

Now we can run omake to build the project. Note that the first time we run omake, it both scans the hello_code.c file for dependencies, and compiles it using the cc compiler. The status line printed at the end indicates how many files were scanned, how many were built, and how many MD5 digests were computed.

    $ omake hello
    *** omake: reading OMakefiles
    *** omake: finished reading OMakefiles (0.0 sec)
    - scan . hello_code.o
    + cc -I. -MM hello_code.c
    - build . hello_code.o
    + cc -I. -c -o hello_code.o hello_code.c
    - build . hello
    + cc -o hello hello_code.o
    *** omake: done (0.5 sec, 1/6 scans, 2/6 rules, 5/22 digests)
    $ omake
    *** omake: reading OMakefiles
    *** omake: finished reading OMakefiles (0.1 sec)
    *** omake: done (0.1 sec, 0/4 scans, 0/4 rules, 0/9 digests)

If we want to change the compile options, we can redefine the CC and CFLAGS variables before the CProgram line. In this example, we will use the gcc compiler with the -g option. In addition, we will specify a .DEFAULT target to be built by default. The EXE variable is defined to be .exe on Win32 systems; it is empty otherwise.

    CC = gcc
    CFLAGS += -g
    CProgram(hello, hello_code)
    .DEFAULT: hello$(EXE)

Here is the corresponding run for omake.

    $ omake
    *** omake: reading OMakefiles
    *** omake: finished reading OMakefiles (0.0 sec)
    - scan . hello_code.o
    + gcc -g -I. -MM hello_code.c
    - build . hello_code.o
    + gcc -g -I. -c -o hello_code.o hello_code.c
    - build . hello
    + gcc -g -o hello hello_code.o
    *** omake: done (0.4 sec, 1/7 scans, 2/7 rules, 3/22 digests)

We can, of course, include multiple files in the program. Suppose we write a new file hello_helper.c. We would include this in the project as follows.

    CC = gcc
    CFLAGS += -g
    CProgram(hello, hello_code hello_helper)
    .DEFAULT: hello$(EXE)

  LARGER PROJECTS

As the project grows it is likely that we will want to build libraries of code. Libraries can be built using the StaticCLibrary function. Here is an example of an OMakefile with two libraries.

    CC = gcc
    CFLAGS += -g
    FOO_FILES = foo_a foo_b
    BAR_FILES = bar_a bar_b bar_c
    StaticCLibrary(libfoo, $(FOO_FILES))
    StaticCLibrary(libbar, $(BAR_FILES))
    # The hello program is linked with both libraries
    LIBS = libfoo libbar
    CProgram(hello, hello_code hello_helper)
    .DEFAULT: hello$(EXE)

  SUBDIRECTORIES

As the project grows even further, it is a good idea to split it into several directories. Suppose we place the libfoo and libbar into subdirectories.

In each subdirectory, we define an OMakefile for that directory. For example, here is an example OMakefile for the foo subdirectory.

    INCLUDES += .. ../bar
    FOO_FILES = foo_a foo_b
    StaticCLibrary(libfoo, $(FOO_FILES))

Note the the INCLUDES variable is defined to include the other directories in the project.

Now, the next step is to link the subdirectories into the main project. The project OMakefile should be modified to include a .SUBDIRS: target.

    # Project configuration
    CC = gcc
    CFLAGS += -g
    # Subdirectories
    .SUBDIRS: foo bar
    # The libraries are now in subdirectories
    LIBS = foo/libfoo bar/libbar
    CProgram(hello, hello_code hello_helper)
    .DEFAULT: hello$(EXE)

Note that the variables CC and CFLAGS are defined before the .SUBDIRS target. These variables remain defined in the subdirectories, so that libfoo and libbar use gcc -g.

If the two directories are to be configured differently, we have two choices. The OMakefile in each subdirectory can be modified with its configuration (this is how it would normally be done). Alternatively, we can also place the change in the root OMakefile.

    # Default project configuration
    CC = gcc
    CFLAGS += -g
    # libfoo uses the default configuration
    .SUBDIRS: foo
    # libbar uses the optimizing compiler
    CFLAGS += -O3
    .SUBDIRS: bar
    # Main program
    LIBS = foo/libfoo bar/libbar
    CProgram(hello, hello_code hello_helper)
    .DEFAULT: hello$(EXE)

Note that the way we have specified it, the CFLAGS variable also contains the -O3 option for the CProgram, and hello_code.c and hello_helper.c file will both be compiled with the -O3 option. If we want to make the change truly local to libbar, we can put the bar subdirectory in its own scope using the section form.

    # Default project configuration
    CC = gcc
    CFLAGS += -g
    # libfoo uses the default configuration
    .SUBDIRS: foo
    # libbar uses the optimizing compiler
    section
        CFLAGS += -O3
        .SUBDIRS: bar
    # Main program does not use the optimizing compiler
    LIBS = foo/libfoo bar/libbar
    CProgram(hello, hello_code hello_helper)
    .DEFAULT: hello$(EXE)

Later, suppose we decide to port this project to Win32, and we discover that we need different compiler flags and an additional library.

    # Default project configuration
    if $(equal $(OSTYPE), Win32)
        CC = cl /nologo
        CFLAGS += /DWIN32 /MT
        export
    else
        CC = gcc
        CFLAGS += -g
        export
    # libfoo uses the default configuration
    .SUBDIRS: foo
    # libbar uses the optimizing compiler
    section
        CFLAGS += $(if $(equal $(OSTYPE), Win32), $(EMPTY), -O3)
        .SUBDIRS: bar
    # Default libraries
    LIBS = foo/libfoo bar/libbar
    # We need libwin32 only on Win32
    if $(equal $(OSTYPE), Win32)
       LIBS += win32/libwin32
       .SUBDIRS: win32
       export
    # Main program does not use the optimizing compiler
    CProgram(hello, hello_code hello_helper)
    .DEFAULT: hello$(EXE)

Note the use of the export directives to export the variable definitions from the if-statements. Variables in omake are scoped---variables in nested blocks (blocks with greater indentation), are not normally defined in outer blocks. The export directive specifies that the variable definitions in the nested blocks should be exported to their parent block.

Finally, for this example, we decide to copy all libraries into a common lib directory. We first define a directory variable, and replace occurrences of the lib string with the variable.

    # The common lib directory
    LIB = $(dir lib)
    # phony target to build just the libraries
    .PHONY: makelibs
    # Default project configuration
    if $(equal $(OSTYPE), Win32)
        CC = cl /nologo
        CFLAGS += /DWIN32 /MT
        export
    else
        CC = gcc
        CFLAGS += -g
        export
    # libfoo uses the default configuration
    .SUBDIRS: foo
    # libbar uses the optimizing compiler
    section
        CFLAGS += $(if $(equal $(OSTYPE), Win32), $(EMPTY), -O3)
        .SUBDIRS: bar
    # Default libraries
    LIBS = $(LIB)/libfoo $(LIB)/libbar
    # We need libwin32 only on Win32
    if $(equal $(OSTYPE), Win32)
       LIBS += $(LIB)/libwin32
       .SUBDIRS: win32
       export
    # Main program does not use the optimizing compiler
    CProgram(hello, hello_code hello_helper)
    .DEFAULT: hello$(EXE)

In each subdirectory, we modify the OMakefiles in the library directories to install them into the $(LIB) directory. Here is the relevant change to foo/OMakefile.

    INCLUDES += .. ../bar
    FOO_FILES = foo_a foo_b
    StaticCLibraryInstall(makelib, $(LIB), libfoo, $(FOO_FILES))

Directory (and file names) evaluate to relative pathnames. Within the foo directory, the $(LIB) variable evaluates to ../lib.

As another example, instead of defining the INCLUDES variable separately in each subdirectory, we can define it in the toplevel as follows.

    INCLUDES = $(ROOT) $(dir foo bar win32)

In the foo directory, the INCLUDES variable will evaluate to the string .. . ../bar ../win32. In the bar directory, it would be .. ../foo . ../win32. In the root directory it would be . foo bar win32.

  OTHER THINGS TO CONSIDER

omake also handles recursive subdirectories. For example, suppose the foo directory itself contains several subdirectories. The foo/OMakefile would then contain its own .SUBDIRS target, and each of its subdirectories would contain its own OMakefile.

  BUILDING OCAML PROGRAMS

By default, omake is also configured with functions for building OCaml programs. The functions for OCaml program use the OCaml prefix. For example, suppose we reconstruct the previous example in OCaml, and we have a file called hello_code.ml that contains the following code.

   open Printf
   let () = printf "Hello world\n"

An example OMakefile for this simple project would contain the following.

    # Use the byte-code compiler
    BYTE_ENABLED = true
    NATIVE_ENABLED = false
    OCAMLCFLAGS += -g
    # Build the program
    OCamlProgram(hello, hello_code)
    .DEFAULT: hello.run

Next, suppose the we have two library subdirectories: the foo subdirectory is written in C, the bar directory is written in OCaml, and we need to use the standard OCaml Unix module.

    # Default project configuration
    if $(equal $(OSTYPE), Win32)
        CC = cl /nologo
        CFLAGS += /DWIN32 /MT
        export
    else
        CC = gcc
        CFLAGS += -g
        export
    # Use the byte-code compiler
    BYTE_ENABLED = true
    NATIVE_ENABLED = false
    OCAMLCFLAGS += -g
    # library subdirectories
    INCLUDES += $(dir foo bar)
    OCAMLINCLUDES += $(dir foo bar)
    .SUBDIRS: foo bar
    # C libraries
    LIBS = foo/libfoo
    # OCaml libraries
    OCAML_LIBS = bar/libbar
    # Also use the Unix module
    OCAML_OTHER_LIBS = unix
    # The main program
    OCamlProgram(hello, hello_code hello_helper)
    .DEFAULT: hello

The foo/OMakefile would be configured as a C library.

    FOO_FILES = foo_a foo_b
    StaticCLibrary(libfoo, $(FOO_FILES))

The bar/OMakefile would build an ML library.

   BAR_FILES = bar_a bar_b bar_c
   OCamlLibrary(libbar, $(BAR_FILES))

NOTES

  THE OMAKEFILE AND OMAKEROOT FILES

OMake uses the OMakefile and OMakeroot files for configuring a project. The syntax of these files is the same, but their role is slightly different. For one thing, every project must have exactly one OMakeroot file in the project root directory. This file serves to identify the project root, and it contains code that sets up the project. In contrast, a multi-directory project will often have an OMakefile in each of the project subdirectories, specifying how to build the files in that subdirectory.

Normally, the OMakeroot file is boilerplate. The following listing is a typical example.

    include $(STDLIB)/build/Common
    include $(STDLIB)/build/C
    include $(STDLIB)/build/OCaml
    include $(STDLIB)/build/LaTeX
    # Redefine the command-line variables
    DefineCommandVars(.)
    # The current directory is part of the project
    .SUBDIRS: .

The include lines include the standard configuration files needed for the project. The $(STDLIB) represents the omake library directory. The only required configuration file is Common. The others are optional; for example, the $(STDLIB)/build/OCaml file is needed only when the project contains programs written in OCaml.

The DefineCommandVars function defines any variables specified on the command line (as arguments of the form VAR=<value>). The .SUBDIRS line specifies that the current directory is part of the project (so the OMakefile should be read).

Normally, the OMakeroot file should be small and project-independent. Any project-specific configuration should be placed in the OMakefiles of the project.

MULTIPLE VERSION SUPPORT

OMake version 0.9.6 introduced preliminary support for multiple, simultaneous versions of a project. Versioning uses the vmount(dir1, dir2) function, which defines a ``virtual mount'' of directory dir1 over directory dir2. A ``virtual mount'' is like a transparent mount in Unix, where the files from dir1 appear in the dir2 namespace, but new files are created in dir2. More precisely, the filename dir2/foo refers to: a) the file dir1/foo if it exists, or b) dir2/foo otherwise.

The vmount function makes it easy to specify multiple versions of a project. Suppose we have a project where the source files are in the directory src/, and we want to compile two versions, one with debugging support and one optimized. We create two directories, debug and opt, and mount the src directory over them.

    section
        CFLAGS += -g
        vmount(-l, src, debug)
        .SUBDIRS: debug
    section
        CFLAGS += -O3
        vmount(-l, src, opt)
        .SUBDIRS: opt

Here, we are using section blocks to define the scope of the vmount---you may not need them in your project.

The -l option is optional. It specifies that files form the src directory should be linked into the target directories (or copied, if the system is Win32). The links are added as files are referenced. If no options are given, then files are not copied or linked, but filenames are translated to refer directly to the src/ files.

Now, when a file is referenced in the debug directory, it is linked from the src directory if it exists. For example, when the file debug/OMakefile is read, the src/OMakefile is linked into the debug/ directory.

The vmount model is fairly transparent. The OMakefiles can be written as if referring to files in the src/ directory---they need not be aware of mounting. However, there are a few points to keep in mind.

  NOTES

*   When using the vmount function for versioning, it wise to keep the source files distinct from the compiled versions. For example, suppose the source directory contained a file src/foo.o. When mounted, the foo.o file will be the same in all versions, which is probably not what you want. It is better to keep the src/ directory pristine, containing no compiled code.

*   When using the vmount -l option, files are linked into the version directory only if they are referenced in the project. Functions that examine the filesystem (like $(ls ...)) may produce unexpected results.

SYNOPSIS

omake [-k] [-jcount] [-n] [-s] [-S] [-p] [-P] [-w] [-t] [-u] [-U] [-R] [--project] [--progress] [--no-progress] [--print-status] [--no-print-status] [--print-exit] [--no-print-exit] [--print-dependencies] [--show-dependencies target] [--force-dotomake] [--dotomake dir] [--flush-includes] [--configure] [--install] [--install-all] [--install-force] [--version] [filename...] [var-definition...]

COMMAND-LINE OPTIONS

-k
     Do not abort when a build command fails; continue to build as much of the project as possible.

-n
     Print the commands that would be executed, but do no execute them. This can be used to see what would happen if the project were to be built.

-s
     Do not print commands as they are executed (be ``silent'').

-S
     Do not print commands as they are executed unless they produce output.

--progress
     Print a progress indicator. This is normally used with the -s or -S options.

--no-progress
     Do not print a progress indicator (default).

--print-exit
     Print termination codes when commands complete.

--no-print-exit
     Do not print termination codes when commands complete (default).

-w
     Print directory information in make format as commands are executed. This is mainly useful for editors that expect make-style directory information for determining the location of errors.

-p
     Watch the filesystem for changes, and continue the build until it succeeds. If this option is specified, omake will restart the build whenever source files are modified.

-P
     Watch the filesystem for changes forever. If this option is specified, omake will restart the build whenever source files are modified.

-R
     Ignore the current directory and build the project from its root directory. When omake is run in a subdirectory of a project, it normally builds files within the current directory and its subdirectories. If the -R option is specified, the build is performed as if omake were run in the project root.

-t
     Update the omake database to force the project to be considered up-to-date.

-U
     Do not trust cached build information. This will force the entire project to be rebuilt.

--depend
     Do not trust cached dependency information. This will force files to be rescanned for dependency information.

--configure
     Re-run static.\ sections of the included omake files, instead of trusting the cached results.

[--force-dotomake]
     Always use the $HOME/.omake for the .omc cache files.

[--dotomake dir]
     Use the specified directory instead of the $HOME/.omake for the placement of the .omc cache files.

-jcount
     Run multiple build commands in parallel. The count specifies a bound on the number of commands to run simultaneously. In addition, the count may specify servers for remote execution of commands in the form server=count. For example, the option -j 2:small.host.org=1:large.host.org=4 would specify that up to 2 jobs can be executed locally, 1 on the server small.host.org and 4 on large.host.org. Each remote server must use the same filesystem location for the project.

Remote execution is currently an experimental feature. Remote filesystems like NFS do not provide adequate file consistency for this to work.

--print-dependencies
     Print dependency information for the targets on the command line.

--show-dependencies target
     Print dependency information if the target is built.

--install
     Install default files OMakefile and OMakeroot into the current directory. You would typically do this to start a project in the current directory.

--install-all
     In addition to installing files OMakefile and OMakeroot, install default OMakefiles into each subdirectory of the current directory. cvs(1) rules are used for filtering the subdirectory list. For example, OMakefiles are not copied into directories called CVS, RCCS, etc.

--install-force
     Normally, omake will prompt before it overwrites any existing OMakefile. If this option is given, all files are forcibly overwritten without prompting.

var-definition
     omake variables can also be defined on the command line in the form name=value. For example, the CFLAGS variable might be defined on the command line with the argument CFLAGS="-Wall -g".

In addition, omake supports a number of debugging flags on the command line. Run omake --help to get a summary of these flags.

OMAKE CONCEPTS AND SYNTAX

Projects are specified to omake with OMakefiles. The OMakefile has a format similar to a Makefile. An OMakefile has three main kinds of syntactic objects: variable definitions, function definitions, and rule definitions.

  VARIABLES

Variables are defined with the following syntax. The name is any sequence of alphanumeric characters, underscore _, and hyphen -.

   <name> = <value>

Values are defined as a sequence of literal characters and variable expansions. A variable expansion has the form $(<name>), which represents the value of the <name> variable in the current environment. Some examples are shown below.

   CC = gcc
   CFLAGS = -Wall -g
   COMMAND = $(CC) $(CFLAGS) -O2

In this example, the value of the COMMAND variable is the string gcc -Wall -g -O2.

Unlike make(1), variable expansion is eager and functional (see also the section on Scoping). That is, variable values are expanded immediately and new variable definitions do not affect old ones. For example, suppose we extend the previous example with following variable definitions.

   X = $(COMMAND)
   COMMAND = $(COMMAND) -O3
   Y = $(COMMAND)

In this example, the value of the X variable is the string gcc -Wall -g -O2 as before, and the value of the Y variable is gcc -Wall -g -O2 -O3.

  ADDING TO A VARIABLE DEFINITION

Variables definitions may also use the += operator, which adds the new text to an existing definition. The following two definitions are equivalent.

   # Add options to the CFLAGS variable
   CFLAGS = $(CFLAGS) -Wall -g
   # The following definition is equivalent
   CFLAGS += -Wall -g

  ARRAYS

Arrays can be defined by appending the [] sequence to the variable name and defining initial values for the elements as separate lines. Whitespace is significant on each line. The following code sequence prints c d e.

    X[] =
        a b
        c d e
        f
    println($(nth 2, $(X)))

  SPECIAL CHARACTERS AND QUOTING

The following characters are special to omake: $():,=#\. To treat any of these characters as normal text, they should be escaped with the backslash character \.

    DOLLAR = \$

Newlines may also be escaped with a backslash to concatenate several lines.

    FILES = a.c\
            b.c\
            c.c

Note that the backslash is not an escape for any other character, so the following works as expected (that is, it preserves the backslashes in the string).

    DOSTARGET = C:\WINDOWS\control.ini

An alternative mechanism for quoting special text is the use $"..." escapes. The number of double-quotations is arbitrary. The outermost quotations are not included in the text.

    A = $""String containing "quoted text" ""
    B = $"""Multi-line
        text.
        The # character is not special"""

  FUNCTION DEFINITIONS

Functions are defined using the following syntax.

   <name>(<params>) =
      <indented-body>

The parameters are a comma-separated list of identifiers, and the body must be placed on a separate set of lines that are indented from the function definition itself. For example, the following text defines a function that concatenates its arguments, separating them with a colon.

    ColonFun(a, b) =
        return($(a):$(b))

The return expression can be used to return a value from the function. A return statement is not required; if it is omitted, the returned value is the value of the last expression in the body to be evaluated. NOTE: as of version 0.9.6, return is a control operation, causing the function to immediately return. In the following example, when the argument a is true, the function f immediately returns the value 1 without evaluating the print statement.

    f(a) =
       if $(a)
          return 1
       println(The argument is false)
       return 0

In many cases, you may wish to return a value from a section or code block without returning from the function. In this case, you would use the value operator. In fact, the value operator is not limited to functions, it can be used any place where a value is required. In the following definition, the variable X is defined as 1 or 2, depending on the value of a, then result is printed, and returned from the function.

    f_value(a) =
       X =
          if $(a)
             value 1
          else
             value 2
       println(The value of X is $(X))
       value $(X)

Functions are called using the GNU-make syntax, $(<name> <args)), where <args> is a comma-separated list of values. For example, in the following program, the variable X contains the value foo:bar.

   X = $(ColonFun foo, bar)

If the value of a function is not needed, the function may also be called using standard function call notation. For example, the following program prints the string ``She says: Hello world''.

    Printer(name) =
        println($(name) says: Hello world)
    Printer(She)

  COMMENTS

Comments begin with the # character and continue to the end of the line.

  FILE INCLUSION

Files may be included with the include form. The included file must use the same syntax as an OMakefile.

    include files.omake

  SCOPING, SECTIONS

Scopes in omake are defined by indentation level. When indentation is increased, such as in the body of a function, a new scope is introduced.

The section form can also be used to define a new scope. For example, the following code prints the line X = 2, followed by the line X = 1.

    X = 1
    section
        X = 2
        println(X = $(X))
    println(X = $(X))

This result may seem surprising--the variable definition within the section is not visible outside the scope of the section.

The export form can be used to circumvent this restriction by exporting variable values from an inner scope. It must be the final expression in a scope. For example, if we modify the previous example by adding an export expression, the new value for the X variable is retained, and the code prints the line X = 2 twice.

    X = 1
    section
        X = 2
        println(X = $(X))
        export
    println(X = $(X))

There are also cases where separate scoping is quite important. For example, each OMakefile is evaluated in its own scope. Since each part of a project may have its own configuration, it is important that variable definitions in one OMakefile do not affect the definitions in another.

To give another example, in some cases it is convenient to specify a separate set of variables for different build targets. A frequent idiom in this case is to use the section command to define a separate scope.

   section
      CFLAGS += -g
      %.c: %.y
          $(YACC) $<
      .SUBDIRS: foo
   .SUBDIRS: bar baz

In this example, the -g option is added to the CFLAGS variable by the foo subdirectory, but not by the bar and baz directories. The implicit rules are scoped as well and in this example, the newly added yacc rule will be inherited by the foo subdirectory, but not by the bar and baz ones; furthermore this implicit rule will not be in scope in the current directory.

  CONDITIONALS

Top level conditionals have the following form.

    if <test>
       <true-clause>
    elseif <text>
       <elseif-clause>
    else
       <else-clause>

The <test> expression is evaluated, and if it evaluates to a true value (see the Logic section), the code for the <true-clause> is evaluated; otherwise the remaining clauses are evaluated. There may be multiple elseif clauses; both the elseif and else clauses are optional. Note that the clauses are indented, so they introduce new scopes.

The following example illustrates a typical use of a conditional. The OSTYPE variable is the current machine architecture.

    # Common suffixes for files
    if $(equal $(OSTYPE), Win32)
       EXT_LIB = .lib
       EXT_OBJ = .obj
       EXT_ASM = .asm
       EXE = .exe
       export
    elseif $(mem $(OSTYPE), Unix Cygwin)
       EXT_LIB = .a
       EXT_OBJ = .o
       EXT_ASM = .s
       EXE =
       export
    else
       # Abort on other architectures
       eprintln(OS type $(OSTYPE) is not recognized)
       exit(1)

  MATCHING

Pattern matching is performed with the switch and match forms.

    switch <string>
    case <pattern1>
        <clause1>
    case <pattern2>
        <clause2>
    ...
    default
       <default-clause>

The number of cases is arbitrary. The default clause is optional; however, if it is used it should be the last clause in the pattern match.

For switch, the string is compared with the patterns literally.

    switch $(HOST)
    case mymachine
        println(Building on mymachine)
    default
        println(Building on some other machine)

Patterns need not be constant strings. The following function tests for a literal match against pattern1, and a match against pattern2 with ## delimiters.

   Switch2(s, pattern1, pattern2) =
      switch $(s)
      case $(pattern1)
          println(Pattern1)
      case $"##$(pattern2)##"
          println(Pattern2)
      default
          println(Neither pattern matched)

For match the patterns are egrep(1)-style regular expressions. The numeric variables $1, $2, ... can be used to retrieve values that are matched by \(...\) expressions.

    match $(NODENAME)@$(SYSNAME)@$(RELEASE)
    case $"mymachine.*@\(.*\)@\(.*\)"
        println(Compiling on mymachine; sysname $1 and release $2 are ignored)
    case $".*@Linux@.*2\.4\.\(.*\)"
        println(Compiling on a Linux 2.4 system; subrelease is $1)
    default
        eprintln(Machine configuration not implemented)
        exit(1)

OBJECTS

OMake is an object-oriented language. Generally speaking, an object is a value that contains fields and methods. An object is defined with a . suffix for a variable. For example, the following object might be used to specify a point $(1, 5)$ on the two-dimensional plane.

    Coord. =
        x = 1
        y = 5
        print(message) =
           println($"$(message): the point is ($(x), $(y)")
    # Define X to be 5
    X = $(Coord.x)
    # This prints the string, "Hi: the point is (1, 5)"
    Coord.print(Hi)

The fields x and y represent the coordinates of the point. The method print prints out the position of the point.

  CLASSES

We can also define classes. For example, suppose we wish to define a generic Point class with some methods to create, move, and print a point. A class is really just an object with a name, defined with the class directive.

    Point. =
        class Point
        # Default values for the fields
        x = 0
        y = 0
        # Create a new point from the coordinates
        new(x, y) =
           this.x = $(x)
           this.y = $(y)
           return $(this)
        # Move the point to the right
        move-right() =
           x = $(add $(x), 1)
           return $(this)
        # Print the point
        print() =
           println($"The point is ($(x), $(y)")
    p1 = $(Point.new 1, 5)
    p2 = $(p1.move-right)
    # Prints "The point is (1, 5)"
    p1.print()
    # Prints "The point is (2, 5)"
    p2.print()

Note that the variable $(this) is used to refer to the current object. Also, classes and objects are functional---the new and move-right methods return new objects. In this example, the object p2 is a different object from p1, which retains the original $(1, 5)$ coordinates.

  INHERITANCE

Classes and objects support inheritance (including multiple inheritance) with the extends directive. The following definition of Point3D defines a point with x, y, and z fields. The new object inherits all of the methods and fields of the parent classes/objects.

    Z. =
       z = 0
    Point3D. =
       extends $(Point)
       extends $(Z)
       class Point3D
       print() =
          println($"The 3D point is ($(x), $(y), $(z))")
    # The "new" method was not redefined, so this
    # defines a new point (1, 5, 0).
    p = $(Point3D.new 1, 5)

SPECIAL OBJECTS/SECTIONS

Objects provide one way to manage the OMake namespace. There are also four special objects that are further used to control the namespace.

  PRIVATE.

The private. section is used to define variables that are private to the current file/scope. The values are not accessible outside the scope. Variables defined in a private. object can be accessed only from within the section where they are defined.

    Obj. =
       private. =
          X = 1
       print() =
          println(The value of X is: $(X))
    # Prints:
    #    The private value of X is: 1
    Obj.print()
    # This is an error--X is private in Obj
    y = $(Obj.X)

In addition, private definitions do not affect the global value of a variable.

   # The public value of x is 1
   x = 1
   f() =
       println(The public value of x is: $(x))
   # This object uses a private value of x
   Obj. =
       private. =
          x = 2
       print() =
          x = 3
          println(The private value of x is: $(x))
          f()
   # Prints:
   #    The private value of x is: 3
   #    The public value of x is: 1
   Obj.print()

Private variables have two additional properties.

1.  Private variables are local to the file in which they are defined.

2.  Private variables are not exported by the export directive, unless they are mentioned explicitly.

       private. =
          FLAG = true
       section
          FLAG = false
          export
       # FLAG is still true
       section
          FLAG = false
          export FLAG
       # FLAG is now false

  PROTECTED.

The protected. object is used to define fields that are local to an object. They can be accessed as fields, but they are not passed dynamically to other functions. The purpose of a protected variable is to prevent a variable definition within the object from affecting other parts of the project.

    X = 1
    f() =
       println(The public value of X is: $(X))
    # Prints:
    #    The public value of X is: 2
    section
       X = 2
       f()
    # X is a protected field in the object
    Obj. =
       protected. =
          X = 3
       print() =
          println(The protected value of X is: $(X))
          f()
    # Prints:
    #    The protected value of X is: 3
    #    The public value of X is: 1
    Obj.print()
    # This is legal, it defines Y as 3
    Y = $(Obj.X)

In general, it is a good idea to define object variables as protected. The resulting code is more modular because variables in your object will not produce unexpected clashes with variables defined in other parts of the project.

  PUBLIC.

The public. object is used to specify public dynamically-scoped variables. In the following example, the public. object specifies that the value X = 4 is to be dynamically scoped. Public variables are not defined as fields of an object.

    X = 1
    f() =
       println(The public value of X is: $(X))
    # Prints:
    #    The public value of X is: 2
    section
       X = 2
       f()
    Obj. =
       protected. =
          X = 3
       print() =
          println(The protected value of X is: $(X))
          public. =
             X = 4
          f()
    # Prints:
    #    The protected value of X is: 3
    #    The public value of X is: 4
    Obj.print()

  STATIC.

The static. object is used to specify values that are persistent across runs of OMake. They are frequently used for configuring a project. Configuring a project can be expensive, so the static. object ensure that the configuration is performed just once. In the following (somewhat trivial) example, a static section is used to determine if the LaTeX command is available. The $(where latex) function returns the full pathname for latex, or false if the command is not found.

   static. =
      LATEX_ENABLED = false
      print(--- Determining if LaTeX is installed )
      if $(where latex)
          LATEX_ENABLED = true
          export
      if $(LATEX_ENABLED)
         println($'(enabled)')
      else
         println($'(disabled)')

As a matter of style, a static. section that is used for configuration should print what it is doing, using --- as a print prefix.

  SHORT SYNTAX FOR SCOPING OBJECTS

The usual dot-notation can be used for private, protected, and public variables (but not static variables).

    # Public definition of X
    public.X = 1
    # Private definition of X
    private.X = 2
    # Prints:
    #    The public value of X is: 1
    #    The private value of X is: 2
    println(The public value of X is: $(public.X))
    println(The private value of X is: $(private.X))

  MODULAR PROGRAMMING

The scoping objects help provide a form of modularity. When you write a new file or program, explicit scoping declarations can be used to define an explicit interface for your code, and help avoid name clashes with other parts of the project. Variable definitions are public by default, but you can control this with private definitions.

    # These variables are private to this file
    private. =
       FILES = foo1 foo2 foo3
       SUFFIX = .o
       OFILES = $(addsuffix $(SUFFIX), $(FILES))
    # These variables are public
    public. =
       CFLAGS += -g
    # Build the files with the -g option
    $(OFILES):

RULES

Rules are used by OMake to specify how to build files. At its simplest, a rule has the following form.

    <target>: <dependencies>
        <commands>

The <target> is the name of a file to be built. The <dependencies> are a list of files that are needed before the <target> can be built. The <commands> are a list of indented lines specifying commands to build the target. For example, the following rule specifies how to compile a file hello.c.

    hello.o: hello.c
        $(CC) $(CFLAGS) -c -o hello.o hello.c

This rule states that the hello.o file depends on the hello.c file. If the hello.c file has changed, the command $(CC) $(CFLAGS) -c -o hello.o hello.c is to be executed to update the target file hello.o.

A rule can have an arbitrary number of commands. The individual command lines are executed independently by the command shell. The commands do not have to begin with a tab, but they must be indented from the dependency line.

In addition to normal variables, the following special variables may be used in the body of a rule.

*   $*: the target name, without a suffix.

*   $@: the target name.

*   $^: a list of the sources, in alphabetical order, with duplicates removed.

*   $+: all the sources, in the original order.

*   $<: the first source.

For example, the above hello.c rule may be simplified as follows.

    hello.o: hello.c
        $(CC) $(CFLAGS) -c -o $@ $<

Unlike normal values, the variables in a rule body are expanded lazily, and binding is dynamic. The following function definition illustrates some of the issues.

    CLibrary(name, files) =
        OFILES = $(addsuffix .o, $(files))
        $(name).a: $(OFILES)
            $(AR) cq $@ $(OFILES)

This function defines a rule to build a program called $(name) from a list of .o files. The files in the argument are specified without a suffix, so the first line of the function definition defines a variable OFILES that adds the .o suffix to each of the file names. The next step defines a rule to build a target library $(name).a from the $(OFILES) files. The expression $(AR) is evaluated when the function is called, and the value of the variable AR is taken from the caller's scope (see also the section on Scoping).

  IMPLICIT RULES

Rules may also be implicit. That is, the files may be specified by wildcard patterns. The wildcard character is %. For example, the following rule specifies a default rule for building .o files.

    %.o: %.c
        $(CC) $(CFLAGS) -c -o $@ $*.c

This rule is a template for building an arbitrary .o file from a .c file.

By default, implicit rules are only used for the targets in the current directory. However subdirectories included via the .SUBDIRS rules inherit all the implicit rules that are in scope (see also the section on Scoping).

  BOUNDED IMPLICIT RULES

Implicit rules may specify the set of files they apply to. The following syntax is used.

    <targets>: <pattern>: <dependencies>
        <commands>

For example, the following rule applies only to the files a.o and b.o.

   a.o b.o: %.o: %.c
        $(CC) $(CFLAGS) -DSPECIAL -c $*.c

  SECTION

Frequently, the commands in a rule body are expressions to be evaluated by the shell. omake also allows expressions to be evaluated by omake itself.

The syntax of these ``computed rules'' uses the section expression. The following rule uses the omake IO functions to produce the target hello.c.

    hello.c:
        section
            FP = fopen(hello.c, w)
            fprintln($(FP), $""#include <stdio.h> int main() { printf("Hello world\n"); }"")
            close($(FP))

This example uses the quotation $""..."" to quote the text being printed. These quotes are not included in the output file. The fopen, fprintln, and close functions perform file IO as discussed in the IO section.

In addition, commands that are function calls, or special expressions, are interpreted correctly. Since the fprintln function can take a file directly, the above rule can be abbreviated as follows.

    hello.c:
       fprintln($@, $""#include <stdio.h> int main() { printf("Hello world\n"); }"")

  SECTION RULE

Rules can also be computed using the section rule form, where a rule body is expected instead of an expression. In the following rule, the file a.c is copied onto the hello.c file if it exists, otherwise hello.c is created from the file default.c.

    hello.c:
        section rule
           if $(target-exists a.c)
              hello.c: a.c
                 cat a.c > hello.c
           else
              hello.c: default.c
                 cp default.c hello.c

SPECIAL DEPENDENCIES

  :EXISTS:

In some cases, the contents of a dependency do not matter, only whether the file exists or not. In this case, the :exists: qualifier can be used for the dependency.

    foo.c: a.c :exists: .flag
       if $(test -e .flag)
           $(CP) a.c $@

  :EFFECTS:

Some commands produce files by side-effect. For example, the latex(1) command produces a .aux file as a side-effect of producing a .dvi file. In this case, the :effects: qualifier can be used to list the side-effect explicitly. omake is careful to avoid simultaneously running programs that have overlapping side-effects.

    paper.dvi: paper.tex :effects: paper.aux
        latex paper

  :VALUE:
The :value: dependency is used to specify that the rule execution depends on the value of an expression. For example, the following rule

    a: b c :value: $(X)
        ...

specifies that ``a'' should be recompiled if the value of $(X) changes (X does not have to be a filename). This is intended to allow greater control over dependencies.

In addition, it can be used instead of other kinds of dependencies. For example, the following rule:

    a: b :exists: c
        commands

is the same as

    a: b :value: $(target-exists c)
        commands

Notes:

*   The values are arbitrary (they are not limited to variables)

*   The values are evaluated at rule expansion time, so expressions containing variables like $@, $^, etc are legal.

.SCANNER RULES

Scanner rules define a way to specify automatic dependency scanning. A .SCANNER rule has the following form.

    .SCANNER: target: dependencies
        commands

The rule is used to compute additional dependencies that might be defined in the source files for the specified target. The scanner produces dependencies for the specified target (which may be a pattern) by running the commands, which must produce output that is compatible with omake. For example, on GNU systems the gcc -MM foo.c produces dependencies for the file foo.c (based on #include information).

We can use this to specify a scanner for C files that adds the scanned dependencies for the .o file. The following scanner specifies that dependencies for a file, say foo.o can be computed by running gcc -MM foo.c. Furthermore, foo.c is a dependency, so the scanner should be recomputed whenever the foo.c file changes.

    .SCANNER: %.o: %.c
        gcc -MM $<

Let's suppose that the command gcc -MM foo.c prints the following line.

    foo.o: foo.h /usr/include/stdio.h

The result is that the files foo.h and /usr/include/stdio.h are considered to be dependencies of foo.o---that is, foo.o should be rebuilt if either of these files changes.

This works, to an extent. One nice feature is that the scanner will be re-run whenever the foo.c file changes. However, one problem is that dependencies in C are recursive. That is, if the file foo.h is modified, it might include other files, establishing further dependencies. What we need is to re-run the scanner if foo.h changes too.

We can do this with a value dependency. The variable $& is defined as the dependency results from any previous scan. We can add these as dependencies using the digest function, which computes an MD5 digest of the files.

    .SCANNER: %.o: %.c :value: $(digest $&)
        gcc -MM $<

Now, when the file foo.h changes, its digest will also change, and the scanner will be re-run because of the value dependency (since $& will include foo.h).

This still is not quite right. The problem is that the C compiler uses a search-path for include files. There may be several versions of the file foo.h, and the one that is chosen depends on the include path. What we need is to base the dependencies on the search path.

The $(digest-in-path-optional ...) function computes the digest based on a search path, giving us a solution that works.

    .SCANNER: %.o: %.c :value: $(digest-in-path-optional $(INCLUDES), $&)
       gcc -MM $(addprefix -I, $(INCLUDES)) $<

  NAMED SCANNERS, AND THE :SCANNER: TARGET

Sometimes it may be useful to specify explicitly which scanner should be used in a rule. For example, we might compile .c files with different options, or (heaven help us) we may be using both gcc and the Microsoft Visual C++ compiler cl. In general, the target of a .SCANNER is not tied to a particular target, and we may name it as we like.

    .SCANNER: scan-gcc-%.c: %.c :value: $(digest-in-path-optional $(INCLUDES), $&)
        gcc -MM $(addprefix -I, $(INCLUDES)) $<
    .SCANNER: scan-cl-%.c: %.c :value: $(digest-in-path-optional $(INCLUDES), $&)
        cl --scan-dependencies-or-something $(addprefix /I, $(INCLUDES)) $<

The next step is to define explicit scanner dependencies. The :scanner: dependency is used for this. In this case, the scanner dependencies are specified explicitly.

    $(GCC_FILES): %.o: %.c :scanner: scan-gcc-%c
        gcc ...
    $(CL_FILES): %.obj: %.c :scanner: scan-cl-%c
        cl ...

Explicit :scanner: scanner specification may also be used to state that a single .SCANNER rule should be used to generate dependencies for more than one target. For example,

    .SCANNER: scan-all-c: $(GCC_FILES) :value: $(digest-in-path-optional $(INCLUDES), $&)
        gcc -MM $(addprefix -I, $(INCLUDES)) $(GCC_FILES)
    $(GCC_FILES): %.o: %.c :scanner: scan-all-c
        ...

The above has the advantage of only running gcc once and a disadvantage that when a single source file changes, all the files will end up being re-scanned.

  NOTES

In most cases, you won't need to define scanners of your own. The standard installation includes default scanners (both explicitly and implicitly named ones) for C, OCaml, and LaTeX files.

The SCANNER_MODE variable controls the usage of implicit scanner dependencies. See the documentation for the SCANNER_MODE variable in omake-root(1) for detail.

The explicit :scanner: dependencies reduce the chances of scanner mis-specifications. In large complicated projects it might be a good idea to set SCANNER_MODE to error and use only the named .SCANNER rules and explicit :scanner: specifications.

OTHER SPECIAL TARGETS

There are several other special targets that define special actions to be take by omake.

  .DEFAULT

The .DEFAULT target specifies a target to be built by default if omake is run without explicit targets. The following rule instructs omake to build the program hello by default

   .DEFAULT: hello

  .SUBDIRS

The .SUBDIRS target is used to specify a set of subdirectories that are part of the project. Each subdirectory should have its own OMakefile, which is evaluated in the context of the current environment.

   .SUBDIRS: src doc tests

This rule specifies that the OMakefiles in each of the src, doc, and tests directories should be read.

In some cases, especially when the OMakefiles are very similar in a large number of subdirectories, it is inconvenient to have a separate OMakefile for each directory. If the .SUBDIRS rule has a body, the body is used instead of the OMakefile.

   .SUBDIRS: src1 src2 src3
      println(Subdirectory $(CWD))
      .DEFAULT: lib.a

In this case, the src1, src2, and src3 files do not need OMakefiles. Furthermore, if one exists, it is ignored. The following includes the file if it exists.

   .SUBDIRS: src1 src2 src3
       if $(file-exists OMakefile)
          include OMakefile
       .DEFAULT: lib.a

  .INCLUDE

The .INCLUDE target is like the include directive, but it specifies a rule to build the file if it does not exist.

   .INCLUDE: config
       echo "CONFIG_READ = true" > config
    echo CONFIG_READ is $(CONFIG_READ)

  .PHONY

A ``phony'' target is a target that is not a real file, but exists to collect a set of dependencies. Phony targets are specified with the .PHONY rule. In the following example, the install target does not correspond to a file, but it corresponds to some commands that should be run whenever the install target is built (for example, by running omake install).

   .PHONY: install
   install: myprogram.exe
      cp myprogram.exe /usr/bin

RULE SCOPING

As we have mentioned before, omake is a scoped language. This provides great flexibility---different parts of the project can define different configurations without interfering with one another (for example, one part of the project might be compiled with CFLAGS=-O3 and another with CFLAGS=-g).

But how is the scope for a target file selected? Suppose we are building a file dir/foo.o. omake uses the following rules to determine the scope.

*   First, if there is an explicit rule for building dir/foo.o (a rule with no wildcards), the context for that rule determines the scope for building the target.

*   Otherwise, the directory dir/ must be part of the project. This normally means that a configuration file dir/OMakefile exists (although, see the .SUBDIRS section for another way to specify the OMakefile). In this case, the scope of the target is the scope at the end of the dir/OMakefile.

To illustrate rule scoping, let's go back to the example of a ``Hello world'' program with two files. Here is an example OMakefile (the two definitions of CFLAGS are for illustration).

    # The executable is compiled with debugging
    CFLAGS = -g
    hello: hello_code.o hello_lib.o
       $(CC) $(CFLAGS) -o $@ $+
    # Redefine CFLAGS
    CFLAGS += -O3

In this project, the target hello is explicit. The scope of the hello target is the line beginning with hello:, where the value of CFLAGS is -g. The other two targets, hello_code.o and hello_lib.o do not appear as explicit targets, so their scope is at the end of the OMakefile, where the CFLAGS variable is defined to be -g -O3. That is, hello will be linked with CFLAGS=-g and the .o files will be compiled with CFLAGS=-g -O3.

We can change this behavior for any of the targets by specifying them as explicit targets. For example, suppose we wish to compile hello_lib.o with a preprocessor variable LIBRARY.

    # The executable is compiled with debugging
    CFLAGS = -g
    hello: hello_code.o hello_lib.o
       $(CC) $(CFLAGS) -o $@ $+
    # Compile hello_lib.o with CFLAGS = -g -DLIBRARY
    section
        CFLAGS += -DLIBRARY
        hello_lib.o:
    # Redefine CFLAGS
    CFLAGS += -O3

In this case, hello_lib.o is also mentioned as an explicit target, in a scope where CFLAGS=-g -DLIBRARY. Since no rule body is specified, it is compiled using the usual implicit rule for building .o files (in a context where CFLAGS=-g -DLIBRARY).

  SCOPING OF IMPLICIT RULES

Implicit rules (rules containing wildcard patterns) are not global, they follow the normal scoping convention. This allows different parts of a project to have different sets of implicit rules. If we like, we can modify the example above to provide a new implicit rule for building hello_lib.o.

    # The executable is compiled with debugging
    CFLAGS = -g
    hello: hello_code.o hello_lib.o
       $(CC) $(CFLAGS) -o $@ $+
    # Compile hello_lib.o with CFLAGS = -g -DLIBRARY
    section
        %.o: %.c
            $(CC) $(CFLAGS) -DLIBRARY -c $<
        hello_lib.o:
    # Redefine CFLAGS
    CFLAGS += -O3

In this case, the target hello_lib.o is built in a scope with a new implicit rule for building %.o files. The implicit rule adds the -DLIBRARY option. This implicit rule is defined only for the target hello_lib.o; the target hello_code.o is built as normal.

  SCOPING OF .SCANNER RULES

Scanner rules are scoped the same way as normal rules. If the .SCANNER rule is explicit (containing no wildcard patterns), then the scope of the scan target is the same as the the rule. If the .SCANNER rule is implicit, then the environment is taken from the :scanner: dependency.

    # The executable is compiled with debugging
    CFLAGS = -g
    hello: hello_code.o hello_lib.o
       $(CC) $(CFLAGS) -o $@ $+
    # scanner for .c files
    .SCANNER: scan-c-%.c: %.c
       $(CC) $(CFLAGS) -MM $<
    # Compile hello_lib.o with CFLAGS = -g -DLIBRARY
    section
        CFLAGS += -DLIBRARY
        hello_lib.o: hello_lib.c :scanner: scan-c-hello_lib.c
           $(CC) $(CFLAGS) -c $<
    # Compile hello_code.c with CFLAGS = -g -O3
    section
        CFLAGS += -O3
        hello_code.o: hello_code.c :scanner: scan-c-hello_code.c
           $(CC) $(CFLAGS) -c $<

Again, this is for illustration---it is unlikely you would need to write a complicated configuration like this! In this case, the .SCANNER rule specifies that the C-compiler should be called with the -MM flag to compute dependencies. For the target hello_lib.o, the scanner is called with CFLAGS=-g -DLIBRARY, and for hello_code.o it is called with CFLAGS=-g -O3.

  SCOPING FOR .PHONY TARGETS

Phony targets (targets that do not correspond to files) are defined with a .PHONY: rule. Phony targets are scoped as usual. The following illustrates a common mistake, where the .PHONY target is declared after it is used.

    # This example is broken!
    all: hello
    hello: hello_code.o hello_lib.o
        $(CC) $(CFLAGS) -o $@ $+
    .PHONY: all

This doesn't work as expected because the .PHONY declaration occurs too late. The proper way to write this example is to place the .PHONY declaration first.

    # Phony targets must be declared before being used
    .PHONY: all
    all: hello
    hello: hello_code.o hello_lib.o
        $(CC) $(CFLAGS) -o $@ $+

Phony targets are passed to subdirectories. As a practical matter, it is wise to declare all .PHONY targets in your root OMakefile, before any .SUBDIRS. This will ensure that 1) they are considered as phony targets in each of the sbdirectories, and 2) you can build them from the project root.

    .PHONY: all install clean
    .SUBDIRS: src lib clib

THE OSH SHELL

OMake also includes a standalone command-line interpreter osh that can be used as an interactive shell. The shell uses the same syntax, and provides the same features on all platforms omake supports, including Win32.

  STARTUP

On startup, osh reads the file ~/.oshrc if it exists. The syntax of this file is the same as an OMakefile. The following additional variables are significant.

prompt
    The prompt variable specifies the command-line prompt. It can be a simple string.

    prompt = osh>

Or you may choose to define it as a function of no arguments.

    prompt() =
        return $"<$(USER):$(HOST) $(homename $(CWD))>"

An example of the latter prompt is as follows.

    <jyh:kenai.yapper.org ~>cd links/omake
    <jyh:kenai.yapper.org ~/links/omake>

ignoreeof
    If the ignoreeof is true, then osh will not exit on a terminal end-of-file (usually ^D on Unix systems).

  ALIASES

Command aliases are defined by adding functions to the Shell. object. The following alias adds the -AF option to the ls command.

    Shell. +=
       ls(argv) =
          "ls" -AF $(argv)

Quoted commands do not undergo alias expansion. The quotation "ls" prevents the alias from being recursive.

  INTERACTIVE SYNTAX

The interactive syntax in osh is the same as the syntax of an OMakefile, with one exception in regard to indentation. The line before an indented block must have a colon at the end of the line. A block is terminated with a . on a line by itself, or ^D. In the following example, the first line if true has no body, because there is no colon.

   # The following if has no body
   osh>if true
   # The following if has a body
   osh>if true:
   if>       if true:
   if>          println(Hello world)
   if>          .
   Hello world

Note that osh makes some effort to modify the prompt while in an indented body, and it auto-indents the text.

The colon signifier is also allowed in files, although it is not required.

  SEE ALSO

See Section omake-shell for more information on the shell language, and Section omake-system for more information on job control.

BUILTIN VARIABLES

  OSTYPE
Set to the machine architecture omake is running on. Possible values are Unix (for all Unix versions, including Linux and Mac OS X), Win32 (for MS-Windows, OMake compiled with MSVC++ or Mingw), and Cygwin (for MS-Windows, OMake compiled with Cygwin).

  SYSNAME
The name of the operating system for the current machine.

  NODENAME
The hostname of the current machine.

  OS_VERSION
The operating system release.

  MACHINE
The machine architecture, e.g. i386, sparc, etc.

  HOST
Same as NODENAME.

  OMAKE_VERSION
Version of OMake.

  USER
The login name of the user executing the process.

  HOME
The home directory of the user executing the process.

  PID
The OMake process id.

BOOLEAN FUNCTIONS AND CONTROL FLOW

  NOT

   $(not e) : String
      e : String

Boolean values in omake are represented by case-insensitive strings. The false value can be represented by the strings false, no, nil, undefined or 0, and everything else is true. The not function negates a Boolean value.

For example, $(not false) expands to the string true, and $(not hello world) expands to false.

  EQUAL

   $(equal e1, e2) : String
      e1 : String
      e2 : String

The equal function tests for equality of two values.

For example $(equal a, b) expands to false, and $(equal hello world, hello world) expands to true.

  AND

    $(and e1, ..., en) : String
       e1, ..., en: Sequence

The and function evaluates to the conjunction of its arguments.

For example, in the following code, X is true, and Y is false.

    A = a
    B = b
    X = $(and $(equal $(A), a) true $(equal $(B), b))
    Y = $(and $(equal $(A), a) true $(equal $(A), $(B)))

  OR

   $(or e1, ..., en) : String
      e1, ..., en: String Sequence

The or function evaluates to the disjunction of its arguments.

For example, in the following code, X is true, and Y is false.

    A = a
    B = b
    X = $(or $(equal $(A), a) false $(equal $(A), $(B)))
    Y = $(or $(equal $(A), $(B)) $(equal $(A), b))

  IF

    $(if e1, e2[, e3]) : value
       e1 : String
       e2, e3 : value

The if function represents a conditional based on a Boolean value. For example $(if $(equal a, b), c, d) evaluates to d.

Conditionals may also be declared with an alternate syntax.

   if e1
      body1
   elseif e2
      body2
   ...
   else
      bodyn

If the expression e1 is not false, then the expressions in body1 are evaluated and the result is returned as the value of the conditional. Otherwise, if e1 evaluates to false, the evaluation continues with the e2 expression. If none of the conditional expressions is true, then the expressions in bodyn are evaluated and the result is returned as the value of the conditional.

There can be any number of elseif clauses; the else clause is optional.

Note that each branch of the conditional defines its own scope, so variables defined in the branches are normally not visible outside the conditional. The export command may be used to export the variables defined in a scope. For example, the following expression represents a common idiom for defining the C compiler configuration.

   if $(equal $(OSTYPE), Win32)
      CC = cl
      CFLAGS += /DWIN32
      export
   else
      CC = gcc
      CFLAGS += -g -O2
      export

  SWITCH, MATCH

The switch and match functions perform pattern matching.

$(switch <arg>, <pattern_1>, <value_1>, ..., <pattern_n>, <value_n>) $(match <arg>, <pattern_1>, <value_1>, ..., <pattern_n>, <value_n>)

The number of <pattern>/<value> pairs is arbitrary. They strictly alternate; the total number of arguments to <match> must be odd.

The <arg> is evaluated to a string, and compared with <pattern_1>. If it matches, the result of the expression is <value_1>. Otherwise evaluation continues with the remaining patterns until a match is found. If no pattern matches, the value is the empty string.

The switch function uses string comparison to compare the argument with the patterns. For example, the following expression defines the FILE variable to be either foo, bar, or the empty string, depending on the value of the OSTYPE variable.

    FILE = $(switch $(OSTYPE), Win32, foo, Unix, bar)

The match function uses regular expression patterns (see the grep function). If a match is found, the variables $1, $2, ... are bound to the substrings matched between \( and \) delimiters. The $0 variable contains the entire match, and $* is an array of the matched substrings. to the matched substrings.

    FILE = $(match foo_xyz/bar.a, foo_\\\(.*\\\)/\\\(.*\\\)\.a, foo_$2/$1.o)

The switch and match functions also have an alternate (more usable) form.

   match e
   case pattern1
      body1
   case pattern2
      body2
   ...
   default
      bodyd

If the value of expression e matches pattern_i and no previous pattern, then body_i is evaluated and returned as the result of the match. The switch function uses string comparison; the match function uses regular expression matching.

   match $(FILE)
   case $".*\(\.[^\/.]*\)"
      println(The string $(FILE) has suffix $1)
   default
      println(The string $(FILE) has no suffix)

  TRY

   try
      try-body
   catch class1(v1)
      catch-body
   when expr
      when-body
   ...
   finally
      finally-body

The try form is used for exception handling. First, the expressions in the try-body are evaluated.

If evaluation results in a value v without raising an exception, then the expressions in the finally-body are evaluated and the value v is returned as the result.

If evaluation of the try-body results in a exception object obj, the catch clauses are examined in order. When examining catch clause catch class(v), if the exception object obj is an instance of the class name class, the variable v is bound to the exception object, and the expressions in the catch-body are evaluated.

If a when clause is encountered while a catch body is being evaluated, the predicate expr is evaluated. If the result is true, evaluation continues with the expressions in the when-body. Otherwise, the next catch clause is considered for evaluation.

If evaluation of a catch-body or when-body completes successfully, returning a value v, without encountering another when clause, then the expressions in the finally-body are evaluated and the value v is returned as the result.

There can be any number of catch clauses; the finally clause is optional.

  RAISE

   raise exn
      exn : Exception

The raise function raises an exception. The exn object can be any object. However, the normal convention is to raise an Exception object.

  EXIT

   exit(code)
      code : Int

The exit function terminates omake abnormally.

$(exit <code>)

The exit function takes one integer argument, which is exit code. Non-zero values indicate abnormal termination.

  DEFINED

   $(defined sequence) : String
      sequence : Sequence

The defined function test whether all the variables in the sequence are currently defined. For example, the following code defines the X variable if it is not already defined.

    if $(not $(defined X))
       X = a b c
       export

  DEFINED-ENV

   $(defined-env sequence) : String
      sequence : String

The defined-env function tests whether a variable is defined as part of the process environment.

For example, the following code adds the -g compile option if the environment variable DEBUG is defined.

if $(defined-env DEBUG)
    CFLAGS += -g
    export

  GETENV

   $(getenv name) : String
   $(getenv name, default) : String

The getenv function gets the value of a variable from the process environment. The function takes one or two arguments.

In the single argument form, an exception is raised if the variable variable is not defined in the environment. In the two-argument form, the second argument is returned as the result if the value is not defined.

For example, the following code defines the variable X to be a space-separated list of elements of the PATH environment variable if it is defined, and to /bin /usr/bin otherwise.

    X = $(split $(PATHSEP), $(getenv PATH, /bin:/usr/bin))

You may also use the alternate form.
     getenv(NAME)
         default

  SETENV

   setenv(name, value)
      name : String
      value : String

The setenv function sets the value of a variable in the process environment. Environment variables are scoped like normal variables.

  GET-REGISTRY

   get-registry(hkey, key, field) : String
   get-registry(hkey, key, field, default) : String
       hkey : String
       key : String
       field : String

The get-registry function retrieves a string value from the system registry on Win32. On other architectures, there is no registry.

The hive (I think that is the right word), indicates which part of the registry to use. It should be one of the following values.

*   HKEY_CLASSES_ROOT

*   HKEY_CURRENT_CONFIG

*   HKEY_CURRENT_USER

*   HKEY_LOCAL_MACHINE

*   HKEY_USERS

Refer to the Microsoft documentation if you want to know what these mean.

The key is the field you want to get from the registry. It should have a form like A\B\C (if you use forward slashes, they will be converted to backslashes). The field is the sub-field of the key.

In the 4-argument form, the default is returned on failure. You may also use the alternate form.

    get-registry(hkey, key, field)
       default

  GETVAR

   $(getvar name) : String

The getvar function gets the value of a variable.

An exception is raised if the variable variable is not defined.

For example, the following code defines X to be the string abc.

    NAME = foo
    foo_1 = abc
    X = $(getvar $(NAME)_1)

  SETVAR

   setvar(name, value)
      name : String
      value : String

The setvar function defines a new variable. For example, the following code defines the variable X to be the string abc.

   NAME = X
   setvar($(NAME), abc)

ARRAYS AND SEQUENCES

  ARRAY

    $(array elements) : Array
       elements : Sequence

The array function creates an array from a sequence. If the <arg> is a string, the elements of the array are the whitespace-separated elements of the string, respecting quotes.

In addition, array variables can be declared as follows.

    A[] =
       <val1>
       ...
       <valn>

In this case, the elements of the array are exactly <val1>, ..., <valn>, and whitespace is preserved literally.

  SPLIT

   $(split sep, elements) : Array
      sep : String
      elements : Sequence

The split function takes two arguments, a string of separators, and a string argument. The result is an array of elements determined by splitting the elements by all occurrence of the separator in the elements sequence.

For example, in the following code, the X variable is defined to be the array /bin /usr/bin /usr/local/bin.

    PATH = /bin:/usr/bin:/usr/local/bin
    X = $(split :, $(PATH))

The sep argument may be omitted. In this case split breaks its arguments along the white space. Quotations are not split.

  CONCAT

   $(concat sep, elements) : String
      sep : String
      elements : Sequence

The concat function takes two arguments, a separator string, and a sequence of elements. The result is a string formed by concatenating the elements, placing the separator between adjacent elements.

For example, in the following code, the X variable is defined to be the string foo_x_bar_x_baz.

    X = foo  bar     baz
    Y = $(concat _x_, $(X))

  LENGTH

   $(length sequence) : Int
      sequence : Sequence

The length function returns the number of elements in its argument.

For example, the expression $(length a b "c d") evaluates to 3.

  NTH

   $(nth i, sequence) : value
      i : Int
      sequence : Sequence
   raises RuntimeException

The nth function returns the nth element of its argument, treated as a list. Counting starts at 0. An exception is raised if the index is not in bounds.

For example, the expression $(nth 1, a "b c" d) evaluates to "b c".

  NTH-HD

   $(nth-hd i, sequence) : value
      i : Int
      sequence : Sequence
   raises RuntimeException

The nth-hd function returns the first i elements of the sequence. An exception is raised if the sequence is not at least i elements long.

For example, the expression $(nth-hd 2, a "b c" d) evaluates to a "b c".

  NTH-TL

   $(nth-tl i, sequence) : value
      i : Int
      sequence : Sequence
   raises RuntimeException

The nth-tl function skips i elements of the sequence and returns the rest. An exception is raised if the sequence is not at least i elements long.

For example, the expression $(nth-tl 1, a "b c" d) evaluates to "b c" d.

  SUB

   $(sub off, len, sequent) : value
      off : Int
      len : Int
      sequence : Sequence
   raises RuntimeException

The sub function returns a subrange of the sequence. Counting starts at 0. An exception is raised if the specified range is not in bounds.

For example, the expression $(sub 1, 2, a "b c" d e) evaluates to "b c" d.

  REV

    $(rev sequence) : Sequence
       sequence : Sequence

The rev function returns the elements of a sequence in reverse order. For example, the expression $(rev a "b c" d) evaluates to d "b c" a.

  STRING

   $(string sequence) : String
      sequence : Sequence

The string function flattens a sequence into a single string. This is similar to the concat function, but the elements are separated by whitespace. The result is treated as a unit; whitespace is significant.

  QUOTE

   $(quote sequence) : String
      sequence : Sequence

The quote function flattens a sequence into a single string and adds quotes around the string. Inner quotation symbols are escaped.

For example, the expression $(quote a "b c" d) evaluates to "a \"b c\" d", and $(quote abc) evaluates to "abc".

  QUOTE-ARGV

   $(quote-argv sequence) : String
      sequence : Sequence

The quote-argv function flattens a sequence into a single string, and adds quotes around the string. The quotation is formed so that a command-line parse can separate the string back into its components.

  HTML-STRING

   $(html-string sequence) : String
      sequence : Sequence

The html-string function flattens a sequence into a single string, and escaped special HTML characters. This is similar to the concat function, but the elements are separated by whitespace. The result is treated as a unit; whitespace is significant.

  ADDSUFFIX

   $(addsuffix suffix, sequence) : Array
      suffix : String
      sequence : Sequence

The addsuffix function adds a suffix to each component of sequence. The number of elements in the array is exactly the same as the number of elements in the sequence.

For example, $(addsuffix .c, a b "c d") evaluates to a.c b.c "c d".c.

  MAPSUFFIX

   $(mapsuffix suffix, sequence) : Array
      suffix : value
      sequence : Sequence

The mapsuffix function adds a suffix to each component of sequence. It is similar to addsuffix, but uses array concatenation instead of string concatenation. The number of elements in the array is twice the number of elements in the sequence.

For example, $(mapsuffix .c, a b "c d") evaluates to a .c b .c "c d" .c.

  ADDSUFFIXES

   $(addsuffixes suffixes, sequence) : Array
      suffixes : Sequence
      sequence : Sequence

The addsuffixes function adds all suffixes in its first argument to each component of a sequence. If suffixes has n elements, and sequence has m elements, the the result has n * m elements.

For example, the $(addsuffixes .c .o, a b c) expressions evaluates to a.c a.o b.c b.o c.o c.a.

  REMOVEPREFIX

   $(removeprefix prefix, sequence) : Array
      prefix : String
      sequence : Array

The removeprefix function removes a prefix from each component of a sequence.

  REMOVESUFFIX

   $(removesuffix sequence) : Array
      sequence : String

The removesuffix function removes the suffixes from each component of a sequence.

For example, $(removesuffix a.c b.foo "c d") expands to a b "c d".

  REPLACESUFFIXES

   $(replacesuffixes old-suffixes, new-suffixes, sequence) : Array
      old-suffixes : Sequence
      new-suffixes : Sequence
      sequence : Sequence

The replacesuffixes function modifies the suffix of each component in sequence. The old-suffixes and new-suffixes sequences should have the same length.

For example, $(replacesuffixes, .h .c, .o .o, a.c b.h c.z) expands to a.o b.o c.z.

  ADDPREFIX

   $(addprefix prefix, sequence) : Array
      prefix : String
      sequence : Sequence

The addprefix function adds a prefix to each component of a sequence. The number of element in the result array is exactly the same as the number of elements in the argument sequence.

For example, $(addprefix foo/, a b "c d") evaluates to foo/a foo/b foo/"c d".

  MAPPREFIX

   $(mapprefix prefix, sequence) : Array
      prefix : String
      sequence : Sequence

The mapprefix function adds a prefix to each component of a sequence. It is similar to addprefix, but array concatenation is used instead of string concatenation. The result array contains twice as many elements as the argument sequence.

For example, $(mapprefix foo, a b "c d") expands to foo a foo b foo "c d".

  ADD-WRAPPER

   $(add-wrapper prefix, suffix, sequence) : Array
      prefix : String
      suffix : String
      sequence : Sequence

The add-wrapper functions adds both a prefix and a suffix to each component of a sequence. For example, the expression $(add-wrapper dir/, .c, a b) evaluates to dir/a.c dir/b.c. String concatenation is used. The array result has the same number of elements as the argument sequence.

  SET

   $(set sequence) : Array
      sequence : Sequence

The set function sorts a set of string components, eliminating duplicates.

For example, $(set z y z "m n" w a) expands to "m n" a w y z.

  MEM

   $(mem elem, sequence) : Boolean
      elem : String
      sequence : Sequence

The mem function tests for membership in a sequence.

For example, $(mem "m n", y z "m n" w a) evaluates to true, while $(mem m n, y z "m n" w a) evaluates to false.

  INTERSECTION

   $(intersection sequence1, sequence2) : Array
      sequence1 : Sequence
      sequence2 : Sequence

The intersection function takes two arguments, treats them as sets of strings, and computes their intersection. The order of the result is undefined, and it may contain duplicates. Use the set function to sort the result and eliminate duplicates in the result if desired.

For example, the expression $(intersection c a b a, b a) evaluates to a b a.

  INTERSECTS

   $(intersects sequence1, sequence2) : Boolean
      sequence1 : Sequence
      sequence2 : Sequence

The intersects function tests whether two sets have a non-empty intersection. This is slightly more efficient than computing the intersection and testing whether it is empty.

For example, the expression $(intersects a b c, d c e) evaluates to true, and $(intersects a b c a, d e f) evaluates to false.

  SET-DIFF

   $(set-diff sequence1, sequence2) : Array
      sequence1 : Sequence
      sequence2 : Sequence

The set-diff function takes two arguments, treats them as sets of strings, and computes their difference (all the elements of the first set that are not present in the second one). The order of the result is undefined and it may contain duplicates. Use the set function to sort the result and eliminate duplicates in the result if desired.

For example, the expression $(set-diff c a b a e, b a) evaluates to c e.

  FILTER

   $(filter patterns, sequence) : Array
      patterns : Sequence
      sequence : Sequence

The filter function picks elements from a sequence. The patterns is a non-empty sequence of patterns, each may contain one occurrence of the wildcard % character.

For example $(filter %.h %.o, a.c x.o b.h y.o "hello world".c) evaluates to x.o b.h y.o.

  FILTER-OUT

   $(filter-out patterns, sequence) : Array
      patterns : Sequence
      sequence : Sequence

The filter-out function removes elements from a sequence. The patterns is a non-empty sequence of patterns, each may contain one occurrence of the wildcard % character.

For example $(filter-out %.c %.h, a.c x.o b.h y.o "hello world".c) evaluates to x.o y.o.

  CAPITALIZE

   $(capitalize sequence) : Array
      sequence : Sequence

The capitalize function capitalizes each word in a sequence. For example, $(capitalize through the looking Glass) evaluates to Through The Looking Glass.

  UNCAPITALIZE

   $(uncapitalize sequence) : Array
      sequence : Sequence

The uncapitalize function uncapitalizes each word in its argument.

For example, $(uncapitalize through the looking Glass) evaluates to through the looking glass.

  UPPERCASE

   $(uppercase sequence) : Array
      sequence : Sequence

The uppercase function converts each word in a sequence to uppercase. For example, $(uppercase through the looking Glass) evaluates to THROUGH THE LOOKING GLASS.

  LOWERCASE

   $(lowercase sequence) : Array
      sequence : Sequence

The lowercase function reduces each word in its argument to lowercase.

For example, $(lowercase through tHe looking Glass) evaluates to through the looking glass.

  SYSTEM

   system(s)
      s : Sequence

The system function is used to evaluate a shell expression. This function is used internally by omake to evaluate shell commands.

For example, the following program is equivalent to the expression system(ls foo).

   ls foo

  SHELL

   $(shell command) : Array
   $(shella command) : Array
   $(shell-code command) : Int
      command : Sequence

The shell function evaluates a command using the command shell, and returns the whitespace-separated words of the standard output as the result.

The shella function acts similarly, but it returns the lines as separate items in the array.

The shell-code function returns the exit code. The output is not diverted.

For example, if the current directory contains the files OMakeroot, OMakefile, and hello.c, then $(shell ls) evaluates to hello.c OMakefile OMakeroot (on a Unix system).

ARITHMETIC

  INT

The int function can be used to create integers. It returns an Int object.

$(int 17).

  FLOAT
The float function can be used to create floating-point numbers. It returns a Float object.

$(float 3.1415926).

  BASIC ARITHMETIC

The following functions can be used to perform basic arithmetic.

*   $(neg <numbers>): arithmetic inverse

*   $(add <numbers>): addition.

*   $(sub <numbers>): subtraction.

*   $(mul <numbers>): multiplication.

*   $(div <numbers>): division.

*   $(mod <numbers>): remainder.

*   $(lnot <numbers>): bitwise inverse.

*   $(land <numbers>): bitwise and.

*   $(lor <numbers>): bitwise or.

*   $(lxor <numbers>): bitwise exclusive-or.

*   $(lsl <numbers>): logical shift left.

*   $(lsr <numbers>): logical shift right.

*   $(asr <numbers>): arithmetic shift right.

  COMPARISONS

The following functions can be used to perform numerical comparisons.

*   $(lt <numbers>): less then.

*   $(le <numbers>): no more than.

*   $(eq <numbers>): equal.

*   $(ge <numbers>): no less than.

*   $(gt <numbers>): greater than.

*   $(ult <numbers>): unsigned less than.

*   $(ule <numbers>): unsigned greater than.

*   $(uge <numbers>): unsigned greater than or equal.

*   $(ugt <numbers>): unsigned greater than.

FIRST-CLASS FUNCTIONS

  FUN

The fun form introduces anonymous functions.

$(fun <v1>, ..., <vn>, <body>)

The last argument is the body of the function. The other arguments are the parameter names.

The three following definitions are equivalent.

    F(X, Y) =
       return($(addsuffix $(Y), $(X)))
    F = $(fun X, Y, $(addsuffix $(Y), $(X)))
    F =
       fun(X, Y)
          value $(addsuffix $(Y), $(X))

  APPLY

The apply operator is used to apply a function.

$(apply <fun>, <args>)

Suppose we have the following function definition.

    F(X, Y) =
       return($(addsuffix $(Y), $(X)))

The the two expressions below are equivalent.

    X = F(a b c, .c)
    X = $(apply $(F), a b c, .c)

  APPLYA

The applya operator is used to apply a function to an array of arguments.

$(applya <fun>, <args>)

For example, in the following program, the value of Z is file.c.

    F(X, Y) =
       return($(addsuffix $(Y), $(X)))
    args[] =
       file
       .c
    Z = $(applya $(F), $(args))

ITERATION AND MAPPING

  FOREACH

The foreach function maps a function over a sequence.

    $(foreach <fun>, <args>)
    foreach(<var>, <args>)
       <body>

For example, the following program defines the variable X as an array a.c b.c c.c.

    X =
       foreach(x, a b c)
          value $(x).c
    # Equivalent expression
    X = $(foreach $(fun x, $(x).c), abc)

There is also an abbreviated syntax.

The export form can also be used in a foreach body. The final value of X is a.c b.c c.c.

    X =
    foreach(x, a b c)
       X += $(x).c
       export

FILE OPERATIONS

  FILE, DIR

   $(file sequence) : File Sequence
      sequence : Sequence
   $(dir sequence) : Dir Sequence
      sequence : Sequence

The file and dir functions define location-independent references to files and directories. In omake, the commands to build a target are executed in the target's directory. Since there may be many directories in an omake project, the build system provides a way to construct a reference to a file in one directory, and use it in another without explicitly modifying the file name. The functions have the following syntax, where the name should refer to a file or directory.

For example, we can construct a reference to a file foo in the current directory.

   FOO = $(file foo)
   .SUBDIRS: bar

If the FOO variable is expanded in the bar subdirectory, it will expand to ../foo.

These commands are often used in the top-level OMakefile to provide location-independent references to top-level directories, so that build commands may refer to these directories as if they were absolute.

   ROOT = $(dir .)
   LIB  = $(dir lib)
   BIN  = $(dir bin)

Once these variables are defined, they can be used in build commands in subdirectories as follows, where $(BIN) will expand to the location of the bin directory relative to the command being executed.

   install: hello
	cp hello $(BIN)

  TMPFILE

    $(tmpfile prefix) : File
    $(tmpfile prefix, suffix) : File
        prefix : String
        suffix : String

The tmpfile function returns the name of a fresh temporary file in the temporary directory.

  IN

   $(in dir, exp) : String Array
      dir : Dir
      exp : expression

The in function is closely related to the dir and file functions. It takes a directory and an expression, and evaluates the expression in that effective directory. For example, one common way to install a file is to define a symbol link, where the value of the link is relative to the directory where the link is created.

The following commands create links in the $(LIB) directory.

    FOO = $(file foo)
    install:
       ln -s $(in $(LIB), $(FOO)) $(LIB)/foo

Note that the in function only affects the expansion of Node (File and Dir) values.

  WHICH

   $(which files) : File Sequence
      files : String Sequence

The which function searches for executables in the current command search path, and returns file values for each of the commands. It is an error if a command is not found.

  WHERE

The where function is similar to which, except it returns the list of all the locations of the given executable (in the order in which the corresponding directories appear in $PATH). In case a command is handled internally by the Shell object, the first string in the output will describe the command as a built-in function.

    % where echo
    echo is a Shell object method (a built-in function)
    /bin/echo

  EXISTS-IN-PATH

   $(exists-in-path files) : String
      files : String Sequence

The exists-in-path function tests whether all executables are present in the current search path.

  BASENAME

   $(basename files) : String Sequence
      files : String Sequence

The basename function returns the base names for a list of files. The basename is the filename with any leading directory components removed.

For example, the expression $(basename dir1/dir2/a.out /etc/modules.conf /foo.ml) evaluates to a.out modules.conf foo.ml.

  ROOTNAME

   $(rootname files) : String Sequence
      files : String Sequence

The rootname function returns the root name for a list of files. The rootname is the filename with the final suffix removed.

For example, the expression $(rootname dir1/dir2/a.out /etc/a.b.c /foo.ml) evaluates to dir1/dir2/a /etc/a.b /foo.

  DIROF

   $(dirof files) : Dir Sequence
      files : File Sequence

The dirof function returns the directory for each of the listed files.

For example, the expression $(dirof dir/dir2/a.out /etc/modules.conf /foo.ml) evaluates to the directories dir1/dir2 /etc /.

  FULLNAME

   $(fullname files) : String Sequence
      files : File Sequence

The fullname function returns the pathname relative to the project root for each of the files or directories.

  ABSNAME

   $(absname files) : String Sequence
      files : File Sequence

The absname function returns the absolute pathname for each of the files or directories.

  HOMENAME

   $(homename files) : String Sequence
      files : File Sequence

The homename function returns the name of a file in tilde form, if possible. The unexpanded forms are computed lazily: the homename function will usually evaluate to an absolute pathname until the first tilde-expansion for the same directory.

  SUFFIX

   $(suffix files) : String Sequence
      files : StringSequence

The suffix function returns the suffixes for a list of files. If a file has no suffix, the function returns the empty string.

For example, the expression $(suffix dir1/dir2/a.out /etc/a /foo.ml) evaluates to .out .ml.

  FILE-EXISTS, TARGET-EXISTS, TARGET-IS-PROPER

   $(file-exists files) : String
   $(target-exists files) : String
   $(target-is-proper files) : String
       files : File Sequence

The file-exists function checks whether the files listed exist. The target-exists function is similar to the file-exists function. However, it returns true if the file exists or if it can be built by the current project. The target-is-proper returns true only if the file can be generated in the current project.

  FILTER-EXISTS, FILTER-TARGETS, FILTER-PROPER-TARGETS

   $(filter-exists files) : File Sequence
   $(filter-targets files) : File Sequence
   $(filter-proper-targets) : File Sequence
      files : File Sequence

The filter-exists, filter-targets, and filter-proper-targets functions remove files from a list of files.

*   filter-exists: the result is the list of files that exist.

*   filter-targets: the result is the list of files either exist, or can be built by the current project.

*   filter-proper-targets: the result is the list of files that can be built in the current project.

One way to create a simple ``clean'' rule that removes generated files from the project is by removing all files that can be built in the current project. CAUTION: you should be careful before you do this. The rule removes any file that can potentially be reconstructed. There is no check to make sure that the commands to rebuild the file would actually succeed. Also, note that no file outside the current project will be deleted.

    .PHONY: clean
    clean:
        rm $(filter-proper-targets $(ls R, .))

See the dependencies-proper function to see an alternate method for removing intermediate files.

If you use CVS, you may wish to use the cvs_realclean program that is distributed with omake.

  FILE-SORT

   $(file-sort order, files) : File Sequence
      order : String
      files : File Sequence

The file-sort function sorts a list of filenames by build order augmented by a set of sort rules. Sort rules are declared using the .ORDER target. The .BUILDORDER defines the default order.

$(file-sort <order>, <files>)

For example, suppose we have the following set of rules.

   a: b c
   b: d
   c: d
   .DEFAULT: a b c d
      echo $(file-sort .BUILDORDER, a b c d)

In the case, the sorter produces the result d b c a. That is, a target is sorted after its dependencies. The sorter is frequently used to sort files that are to be linked by their dependencies (for languages where this matters).

There are three important restrictions to the sorter:

*   The sorter can be used only within a rule body. The reason for this is that all dependencies must be known before the sort is performed.

*   The sorter can only sort files that are buildable in the current project.

*   The sorter will fail if the dependencies are cyclic.

  SORT RULE

It is possible to further constrain the sorter through the use of sort rules. A sort rule is declared in two steps. The target must be listed as an .ORDER target; and then a set of sort rules must be given. A sort rule defines a pattern constraint.

   .ORDER: .MYORDER
   .MYORDER: %.foo: %.bar
   .MYORDER: %.bar: %.baz
   .DEFAULT: a.foo b.bar c.baz d.baz
      echo $(sort .MYORDER, a.foo b.bar c.baz d.baz)

In this example, the .MYORDER sort rule specifies that any file with a suffix .foo should be placed after any file with suffix .bar, and any file with suffix .bar should be placed after a file with suffix .baz.

In this example, the result of the sort is d.baz c.baz b.bar a.foo.

  FILE-CHECK-SORT

   file-check-sort(files)
      files : File Sequence
   raises RuntimeException

The file-check-sort function checks whether a list of files is in sort order. If so, the list is returned unchanged. If not, the function raises an exception.

$(file-check-sort <order>, <files>)

  GLOB

   $(glob strings) : Node Array
      strings : String Sequence
   $(glob options, strings) : Node Array
      options : String
      strings : String Sequence

The glob function performs glob-expansion.

The . and .. entries are always ignored.

The options are:

b   Do not perform csh(1)-style brace expansion.

e   The \ character does not escape special characters.

n   If an expansion fails, return the expansion literally instead of aborting.

i   If an expansion fails, it expands to nothing.

.   Allow wildcard patterns to match files beginning with a .

A   Return all files, including files that begin with a .

D   Match only directory files.

C   Ignore files according to cvs(1) rules.

P   Include only proper subdirectories.

In addition, the following variables may be defined that affect the behavior of glob.

GLOB_OPTIONS
    A string containing default options.

GLOB_IGNORE
    A list of shell patterns for filenames that glob should ignore.

GLOB_ALLOW
    A list of shell patterns. If a file does not match a pattern in GLOB_ALLOW, it is ignored.

The returned files are sorted by name.

  LS

   $(ls files) : Node Array
      files : String Sequence
   $(ls options, files) : Node Array
      files : String Sequence

The ls function returns the filenames in a directory.

The . and .. entries are always ignored. The patterns are shell-style patterns, and are glob-expanded.

The options include all of the options to the glob function, plus the following.

R   Perform a recursive listing.

The GLOB_ALLOW and GLOB_IGNORE variables can be defined to control the globbing behavior. The returned files are sorted by name.

  SUBDIRS

   $(subdirs dirs) : Dir Array
      dirs : String Sequence
   $(subdirs options, dirs) : Dir Array
      options : String
      dirs : String Sequence

The subdirs function returns all the subdirectories of a list of directories, recursively.

The possible options are the following:

A   Return directories that begin with a .

C   Ignore files according to .cvsignore rules.

P   Include only proper subdirectories.

  MKDIR

   mkdir(mode, node...)
      mode : Int
      node : Node
   raises RuntimeException
   mkdir(node...)
      node : Node
   raises RuntimeException

The mkdir function creates a directory, or a set of directories. The following options are supported.

-m mode
    Specify the permissions of the created directory.

-p  Create parent directories if they do not exist.

--  Interpret the remaining names literally.

  STAT

The Stat object represents the result returned by the stat and lstat functions. It contains the following fields.

A stat object has the following fields. Not all of the fields will have meaning on all architectures.

dev : the device number.

ino : the inode number.

kind
    : the kind of the file, one of the following: REG (regular file), DIR (directory), CHR (character device), BLK (block device), LNK (symbolic link), FIFO (named pipe), SOCK (socket).

perm
    : access rights, represented as an integer.

nlink
    : number of links.

uid : user id of the owner.

gid : group id of the file's group.

rdev
    : device minor number.

size
    : size in bytes.

atime
    : last access time, as a floating point number.

mtime
    : last modification time, as a floating point number.

ctime
    : last status change time, as a floating point number.

  STAT

    $(stat node...) : Stat
       node : Node or Channel
    $(lstat node...) : Stat
       node : Node or Channel
    raises RuntimeException

The stat functions return file information. If the file is a symbolic link, the stat function refers to the destination of the link; the lstat function refers to the link itself.

  UNLINK

   $(unlink file...)
      file : File
   #(rm file...)
      file : File
   $(rmdir dir...)
      dir : Dir
   raises RuntimeException

The unlink and rm functions remove a file. The rmdir function removes a directory.

The following options are supported for rm and rmdir.

-f  ignore nonexistent files, never prompt.

-i  prompt before removal.

-r  remove the contents of directories recursively.

-v  explain what is going on.

--  the rest of the values are interpreted literally.

  RENAME

    rename(old, new)
       old : Node
       new : Node
    mv(nodes... dir)
       nodes : Node Sequence
       dir   : Dir
    cp(nodes... dir)
       nodes : Node Sequence
       dir   : Dir
    raises RuntimeException

The rename function changes the name of a file or directory named old to new.

The mv function is similar, but if new is a directory, and it exists, then the files specified by the sequence are moved into the directory. If not, the behavior of mv is identical to rename. The cp function is similar, but the original file is not removed.

The mv and cp functions take the following options.

-f  Do not prompt before overwriting.

-i  Prompt before overwriting.

-v  Explain what it happening.

-r  Copy the contents of directories recursively.

--  Interpret the remaining arguments literally.

  LINK

   link(src, dst)
      src : Node
      dst : Node
   raises RuntimeException

The link function creates a hard link named dst to the file or directory src.

Hard links are not supported in Win32.

Normally, only the superuser can create hard links to directories.

  SYMLINK

   symlink(src, dst)
      src : Node
      dst : Node
   raises RuntimeException

The symlink function creates a symbolic link dst that points to the src file.

The link name is computed relative to the target directory. For example, the expression $(symlink a/b, c/d) creates a link named c/d -> ../a/b.

Symbolic links are not supported in Win32.

  READLINK

   $(readlink node...) : Node
      node : Node

The readlink function reads the value of a symbolic link.

  CHMOD

   chmod(mode, dst...)
      mode : Int
      dst : Node or Channel
   chmod(mode dst...)
      mode : String
      dst : Node Sequence
   raises RuntimeException

The chmod function changes the permissions of the targets. The chmod function does nothing on Win32 platforms.

Options:

-v  Explain what is happening.

-r  Change files and directories recursively.

-f  Continue on errors.

--  Interpret the remaining argument literally.

  CHOWN

   chown(uid, gid, node...)
      uid : Int
      gid : Int
      node : Node or Channel
   chown(uid, node...)
      uid : Int
      node : Node or Channel
   raises RuntimeException

The chown function changes the user and group id of the file. If the gid is not specified, it is not changed. If either id is -1, that id is not changed.

  UMASK

    $(umask mode) : Int
       mode : Int
    raises RuntimeException

Sets the file mode creation mask. The previous mask is returned. This value is not scoped, changes have global effect.

  DIGEST

     $(digest files) : String Array
        file : File Array
     raises RuntimeException
     $(digest-optional files) : String Array
        file : File Array

The digest and digest-optional functions compute MD5 digests of files. The digest function raises an exception if a file does no exist. The digest-optional returns false if a file does no exist. MD5 digests are cached.

  FIND-IN-PATH

    $(find-in-path path, files) : File Array
       path : Dir Array
       files : String Array
    raises RuntimeException
    $(find-in-path-optional path, files) : File Array

The find-in-path function searches for the files in a search path. Only the tail of the filename is significant. The find-in-path function raises an exception if the file can't be found. The find-in-path-optional function silently removes files that can't be found.

  DIGEST-PATH

    $(digest-in-path path, files) : String/File Array
       path : Dir Array
       files : String Array
    raises RuntimeException
    $(digest-in-path-optional path, files) : String/File Array

The digest-in-path function searches for the files in a search path and returns the file and digest for each file. Only the tail of the filename is significant. The digest-in-path function raises an exception if the file can't be found. The digest-in-path-optional function silently removes elements that can't be found.

  REHASH

    rehash()

The rehash function resets all search paths.

  VMOUNT

    vmount(src, dst)
       src, dst : Dir
    vmount(flags, src, dst)
       flags : String
       src, dst : Dir

``Mount'' the src directory on the dst directory. This is a virtual mount, changing the behavior of the $(file ...) function. When the $(file str) function is used, the resulting file is taken relative to the src directory if the file exists. Otherwise, the file is relative to the current directory.

The main purpose of the vmount function is to support multiple builds with separate configurations or architectures.

The options are as follows.

l   Create symbolic links to files in the src directory.

c   Copy files from the src directory.

Mount operations are scoped.

  ADD-PROJECT-DIRECTORIES

    add-project-directories(dirs)
       dirs : Dir Array

Add the directories to the set of directories that omake considers to be part of the project. This is mainly used to avoid omake complaining that the current directory is not part of the project.

  REMOVE-PROJECT-DIRECTORIES

    remove-project-directories(dirs)
       dirs : Dir Array

Removed the directories from the set of directories that omake considers to be part of the project. This is mainly used to cancel a .SUBDIRS from including a directory if it is determined that the directory does not need to be compiled.

  TEST

   test(exp) : Bool
      exp : String Sequence

The expression grammar is as follows:

*   ! expression : expression is not true

*   expression1 -a expression2 : both expressions are true

*   expression1 -o expression2 : at least one expression is true

*   ( expression ) : expression is true

The base expressions are:

*   -n string : The string has nonzero length

*   -z string : The string has zero length

*   string = string : The strings are equal

*   string != string : The strings are not equal

*   int1 -eq int2 : The integers are equal

*   int1 -ne int2 : The integers are not equal

*   int1 -gt int2 : int1 is larger than int2

*   int1 -ge int2 : int2 is not larger than int1

*   int1 -lt int2 : int1 is smaller than int2

*   int1 -le int2 : int1 is not larger than int2

*   file1 -ef file2 : On Unix, file1 and file2 have the same device and inode number. On Win32, file1 and file2 have the same name.

*   file1 -nt file2 : file1 is newer than file2

*   file1 -ot file2 : file1 is older than file2

*   -b file : The file is a block special file

*   -c file : The file is a character special file

*   -d file : The file is a directory

*   -e file : The file exists

*   -f file : The file is a normal file

*   -g file : The set -group-id bit is set on the file

*   -G file : The file's group is the current effective group

*   -h file : The file is a symbolic link (also -L)

*   -k file : The file's sticky bit is set

*   -L file : The file is a symbolic link (also -h)

*   -O file : The file's owner is the current effective user

*   -p file : The file is a named pipe

*   -r file : The file is readable

*   -s file : The file is empty

*   -S file : The file is a socket

*   -u file : The set -user-id bit is set on the file

*   -w file : The file is writable

*   -x file : The file is executable

A string is any sequence of characters; leading - characters are allowed.

An int is a string that can be interpreted as an integer. Unlike traditional versions of the test program, the leading characters may specify an arity. The prefix 0b means the numbers is in binary; the prefix 0o means the number is in octal; the prefix 0x means the number is in hexadecimal. An int can also be specified as -l string, which evaluates to the length of the string.

A file is a string that represents the name of a file.

  FIND

   find(exp) : Node Array
      exp : String Sequence

The find function searches a directory recursively, returning the files for which the expression evaluates to true.

The expression argument uses the same syntax as the test function, with the following exceptions.

1.  The expression may begin with a directory. If not specified, the current directory is searched.

2.  The {} string expands to the current file being examined.

The syntax of the expression is the same as test, with the following additions.

*   -name string : The current file matches the regular expression.

IO FUNCTIONS

  STANDARD CHANNELS

The following variables define the standard channels.

stdin

stdin : InChannel

The standard input channel, open for reading.

stdout
    stdout : OutChannel

The standard output channel, open for writing.

stderr
    stderr : OutChannel

The standard error channel, open for writing.

  FOPEN

The fopen function opens a file for reading or writing.

   $(fopen file, mode) : Channel
      file : File
      mode : String

The file is the name of the file to be opened. The mode is a combination of the following characters.

r   Open the file for reading; it is an error if the file does not exist.

w   Open the file for writing; the file is created if it does not exist.

a   Open the file in append mode; the file is created if it does not exist.

+   Open the file for both reading an writing.

t   Open the file in text mode (default).

b   Open the file in binary mode.

n   Open the file in nonblocking mode.

x   Fail if the file already exists.

Binary mode is not significant on Unix systems, where text and binary modes are equivalent.

  CLOSE

    $(close channel...)
       channel : Channel

The close function closes a file that was previously opened with fopen.

  READ

   $(read channel, amount) : String
      channel : InChannel
      amount  : Int
   raises RuntimeException

The read function reads up to amount bytes from an input channel, and returns the data that was read. If an end-of-file condition is reached, the function raises a RuntimeException exception.

  WRITE

   $(write channel, buffer, offset, amount) : String
      channel : OutChannel
      buffer  : String
      offset  : Int
      amount  : Int
   $(write channel, buffer) : String
      channel : OutChannel
      buffer  : String
   raises RuntimeException

In the 4-argument form, the write function writes bytes to the output channel channel from the buffer, starting at position offset. Up to amount bytes are written. The function returns the number of bytes that were written.

The 3-argument form is similar, but the offset is 0.

In the 2-argument form, the offset is 0, and the amount if the length of the buffer.

If an end-of-file condition is reached, the function raises a RuntimeException exception.

  LSEEK

    $(lseek channel, offset, whence) : Int
       channel : Channel
       offset  : Int
       whence  : String
    raises RuntimeException

The lseek function repositions the offset of the channel channel according to the whence directive, as follows:

SEEK_SET
    The offset is set to offset.

SEEK_CUR
    The offset is set to its current position plus offset bytes.

SEEK_END
    The offset is set to the size of the file plus offset bytes.

The lseek function returns the new position in the file.

  REWIND

   rewind(channel...)
      channel : Channel

The rewind function set the current file position to the beginning of the file.

  TELL

    $(tell channel...) : Int...
       channel : Channel
    raises RuntimeException

The tell function returns the current position of the channel.

  FLUSH

   $(flush channel...)
      channel : OutChannel

The flush function can be used only on files that are open for writing. It flushes all pending data to the file.

  DUP

    $(dup channel) : Channel
       channel : Channel
    raises RuntimeException

The dup function returns a new channel referencing the same file as the argument.

  DUP2

   dup2(channel1, channel2)
      channel1 : Channel
      channel2 : Channel
   raises RuntimeException

The dup2 function causes channel2 to refer to the same file as channel1.

  SET-NONBLOCK

   set-nonblock-mode(mode, channel...)
      channel : Channel
      mode : String

The set-nonblock-mode function sets the nonblocking flag on the given channel. When IO is performed on the channel, and the operation cannot be completed immediately, the operations raises a RuntimeException.

  SET-CLOSE-ON-EXEC-MODE

   set-close-on-exec-mode(mode, channel...)
      channel : Channel
      mode : String
   raises RuntimeException

The set-close-on-exec-mode function sets the close-on-exec flags for the given channels. If the close-on-exec flag is set, the channel is not inherited by child processes. Otherwise it is.

  PIPE

   $(pipe) : Pipe
   raises RuntimeException

The pipe function creates a Pipe object, which has two fields. The read field is a channel that is opened for reading, and the write field is a channel that is opened for writing.

  MKFIFO

   mkfifo(mode, node...)
      mode : Int
      node : Node

The mkfifo function creates a named pipe.

  SELECT

   $(select rfd..., wfd..., wfd..., timeout) : Select
      rfd : InChannel
      wfd : OutChannel
      efd : Channel
      timeout : float
   raises RuntimeException

The select function polls for possible IO on a set of channels. The rfd are a sequence of channels for reading, wfd are a sequence of channels for writing, and efd are a sequence of channels to poll for error conditions. The timeout specifies the maximum amount of time to wait for events.

On successful return, select returns a Select object, which has the following fields:

read
    An array of channels available for reading.

write
    An array of channels available for writing.

error
    An array of channels on which an error has occurred.

  LOCKF

    lockf(channel, command, len)
       channel : Channel
       command : String
       len : Int
    raises RuntimeException

The lockf function places a lock on a region of the channel. The region starts at the current position and extends for len bytes.

The possible values for command are the following.

F_ULOCK
    Unlock a region.

F_LOCK
    Lock a region for writing; block if already locked.

F_TLOCK
    Lock a region for writing; fail if already locked.

F_TEST
    Test a region for other locks.

F_RLOCK
    Lock a region for reading; block if already locked.

F_TRLOCK
    Lock a region for reading; fail is already locked.

  INETADDR

The InetAddr object describes an Internet address. It contains the following fields.

addr
    String: the Internet address.

port
    Int: the port number.

  HOST

A Host object contains the following fields.

name
    String: the name of the host.

aliases
    String Array: other names by which the host is known.

addrtype
    String: the preferred socket domain.

addrs
    InetAddr Array: an array of Internet addresses belonging to the host.

  GETHOSTBYNAME

   $(gethostbyname host...) : Host...
      host : String
   raises RuntimeException

The gethostbyname function returns a Host object for the specified host. The host may specify a domain name or an Internet address.

  PROTOCOL

The Protocol object represents a protocol entry. It has the following fields.

name
    String: the canonical name of the protocol.

aliases
    String Array: aliases for the protocol.

proto
    Int: the protocol number.

  GETPROTOBYNAME

   $(getprotobyname name...) : Protocol...
      name : Int or String
   raises RuntimeException

The getprotobyname function returns a Protocol object for the specified protocol. The name may be a protocol name, or a protocol number.

  SERVICE

The Service object represents a network service. It has the following fields.

name
    String: the name of the service.

aliases
    String Array: aliases for the service.

port
    Int: the port number of the service.

proto
    Protocol: the protocol for the service.

  GETSERVBYNAME

   $(getservbyname service...) : Service...
      service : String or Int
   raises RuntimeException

The getservbyname function gets the information for a network service. The service may be specified as a service name or number.

  SOCKET

   $(socket domain, type, protocol) : Channel
      domain : String
      type : String
      protocol : String
   raises RuntimeException

The socket function creates an unbound socket.

The possible values for the arguments are as follows.

The domain may have the following values.

PF_UNIX or unix
    Unix domain, available only on Unix systems.

PF_INET or inet
    Internet domain, IPv4.

PF_INET6 or inet6
    Internet domain, IPv6.

The type may have the following values.

SOCK_STREAM or stream
    Stream socket.

SOCK_DGRAM or dgram
    Datagram socket.

SOCK_RAW or raw
    Raw socket.

SOCK_SEQPACKET or seqpacket
    Sequenced packets socket

The protocol is an Int or String that specifies a protocol in the protocols database.

  BIND

   bind(socket, host, port)
      socket : InOutChannel
      host : String
      port : Int
   bind(socket, file)
      socket : InOutChannel
      file : File
   raise RuntimeException

The bind function binds a socket to an address.

The 3-argument form specifies an Internet connection, the host specifies a host name or IP address, and the port is a port number.

The 2-argument form is for Unix sockets. The file specifies the filename for the address.

  LISTEN

   listen(socket, requests)
      socket : InOutChannel
      requests : Int
   raises RuntimeException

The listen function sets up the socket for receiving up to requests number of pending connection requests.

  ACCEPT

   $(accept socket) : InOutChannel
      socket : InOutChannel
   raises RuntimeException

The accept function accepts a connection on a socket.

  CONNECT

    connect(socket, addr, port)
       socket : InOutChannel
       addr : String
       port : int
    connect(socket, name)
       socket : InOutChannel
       name : File
    raise RuntimeException

The connect function connects a socket to a remote address.

The 3-argument form specifies an Internet connection. The addr argument is the Internet address of the remote host, specified as a domain name or IP address. The port argument is the port number.

The 2-argument form is for Unix sockets. The name argument is the filename of the socket.

  GETCHAR

    $(getc) : String
    $(getc file) : String
       file : InChannel or File
    raises RuntimeException

The getc function returns the next character of a file. If the argument is not specified, stdin is used as input. If the end of file has been reached, the function returns false.

  GETS

   $(gets) : String
   $(gets channel) : String
      channel : InChannel or File
   raises RuntimeException

The gets function returns the next line from a file. The function returns the empty string if the end of file has been reached. The line terminator is removed.

  FGETS

   $(fgets) : String
   $(fgets channel) : String
      channel : InChannel or File
   raises RuntimeException

The fgets function returns the next line from a file that has been opened for reading with fopen. The function returns the empty string if the end of file has been reached. The returned string is returned as literal data. The line terminator is not removed.

  PRINTING FUNCTIONS

Output is printed with the print and println functions. The println function adds a terminating newline to the value being printed, the print function does not.

    fprint(<file>, <string>)
    print(<string>)
    eprint(<string>)
    fprintln(<file>, <string>)
    println(<string>)
    eprintln(<string>)

The fprint functions print to a file that has been previously opened with fopen. The print functions print to the standard output channel, and the eprint functions print to the standard error channel.

  VALUE PRINTING FUNCTIONS

Values can be printed with the printv and printvln functions. The printvln function adds a terminating newline to the value being printed, the printv function does not.

    fprintv(<file>, <string>)
    printv(<string>)
    eprintv(<string>)
    fprintvln(<file>, <string>)
    printvln(<string>)
    eprintvln(<string>)

The fprintv functions print to a file that has been previously opened with fopen. The printv functions print to the standard output channel, and the eprintv functions print to the standard error channel.

HIGHER-LEVEL IO FUNCTIONS

  REGULAR EXPRESSIONS

Many of the higher-level functions use regular expressions. Regular expressions are defined by strings with syntax nearly identical to awk(1).

Strings may contain the following character constants.

*   \\ : a literal backslash.

*   \a : the alert character ^G.

*   \b : the backspace character ^H.

*   \f : the formfeed character ^L.

*   : the newline character ^J.

*   \r : the carriage return character ^M.

*   \t : the tab character ^I.

*   \v : the vertical tab character.

*   \xhh... : the character represented by the string of hexadecimal digits h. All valid hexadecimal digits following the sequence are considered to be part of the sequence.

*   \ddd : the character represented by 1, 2, or 3 octal digits.

Regular expressions are defined using the special characters .\^$[(){}*?+.

*   c : matches the literal character c if c is not a special character.

*   \c : matches the literal character c, even if c is a special character.

*   . : matches any character, including newline.

*   ^ : matches the beginning of a line.

*   $ : matches the end of line.

*   [abc...] : matches any of the characters abc...

*   [^abc...] : matches any character except abc...

*   r1|r2 : matches either r1 or r2.

*   r1r2 : matches r1 and then r2.

*   r+ : matches one or more occurrences of r.

*   r* : matches zero or more occurrences of r.

*   r? : matches zero or one occurrence of r.

*   (r) : parentheses are used for grouping; matches r.

*   \(r\) : also defines grouping, but the expression matched within the parentheses is available to the output processor through one of the variables $1, $2, ...

*   r{n} : matches exactly n occurrences of r.

*   r{n,} : matches n or more occurrences of r.

*   r{n,m} : matches at least n occurrences of r, and no more than m occurrences.

*   \y: matches the empty string at either the beginning or end of a word.

*   \B: matches the empty string within a word.

*   \<: matches the empty string at the beginning of a word.

*   \>: matches the empty string at the end of a word.

*   \w: matches any character in a word.

*   \W: matches any character that does not occur within a word.

*   \`: matches the empty string at the beginning of a file.

*   \': matches the empty string at the end of a file.

Character classes can be used to specify character sequences abstractly. Some of these sequences can change depending on your LOCALE.

*   [:alnum:] Alphanumeric characters.

*   [:alpha:] Alphabetic characters.

*   [:lower:] Lowercase alphabetic characters.

*   [:upper:] Uppercase alphabetic characters.

*   [:cntrl:] Control characters.

*   [:digit:] Numeric characters.

*   [:xdigit:] Numeric and hexadecimal characters.

*   [:graph:] Characters that are printable and visible.

*   [:print:] Characters that are printable, whether they are visible or not.

*   [:punct:] Punctuation characters.

*   [:blank:] Space or tab characters.

*   [:space:] Whitespace characters.

  CAT

    cat(files) : Sequence
       files : File or InChannel Sequence

The cat function concatenates the output from multiple files and returns it as a string.

  GREP

   grep(pattern) : String  # input from stdin, default options
      pattern : String
   grep(pattern, files) : String  # default options
      pattern : String
      files   : File Sequence
   grep(options, pattern, files) : String
     options : String
     pattern : String
     files   : File Sequence

The grep function searches for occurrences of a regular expression pattern in a set of files, and prints lines that match. This is like a highly-simplified version of grep(1).

The options are:

q   If specified, the output from grep is not displayed.

n   If specified, output lines include the filename.

The pattern is a regular expression.

If successful (grep found a match), the function returns true. Otherwise, it returns false.

  AWK

   awk(input-files)
   case pattern1:
      body1
   case pattern2:
      body2
   ...
   default:
      bodyd

The awk function provides input processing similar to awk(1), but more limited. The function takes filename arguments. If called with no arguments, the input is taken from stdin. If arguments are provided, each specifies an InChannel, or the name of a file for input. Output is always to stdout.

The variables RS and FS define record and field separators as regular expressions. The default value of RS is the regular expression \r| |\r . The default value of FS is the regular expression [ \t]+.

The awk function operates by reading the input one record at a time, and processing it according to the following algorithm.

For each line, the record is first split into fields using the field separator FS, and the fields are bound to the variables $1, $2, .... The variable $0 is defined to be the entire line, and $* is an array of all the field values. The $(NF) variable is defined to be the number of fields.

Next, the cases are evaluated in order. For each case, if the regular expression pattern_i matches the record $0, then body_i is evaluated. If the body ends in an export, the state is passed to the next clause. Otherwise the value is discarded. If the regular expression contains \(r\) expression, those expression override the fields $1, $2, ....

For example, here is an awk function to print the text between two delimiters \begin{<name>} and \end{<name>}, where the <name> must belong to a set passed as an argument to the filter function.

    filter(names) =
       print = false
       awk(Awk.in)
       case $"^\\end\{\([:alpha:]+\)
          if $(mem $1, $(names))
             print = false
             export
          export
       default
          if $(print)
             println($0)
       case $"^\\begin\{\([:alpha:]+\)
          print = $(mem $1, $(names))
          export

Note, if you want to redirect the output to a file, the easiest way is to redefine the stdout variable. The stdout variable is scoped the same way as other variables, so this definition does not affect the meaning of stdout outside the filter function.

    filter(names) =
        stdout = $(fopen file.out, w)
        awk(Awk.in)
           ...
        close(stdout)

  FSUBST

   fsubst(files)
   case pattern1 [options]
      body1
   case pattern2 [options]
      body2
   ...
   default
      bodyd

The fsubst function provides a sed(1)-like substitution function. Similar to awk, if fsubst is called with no arguments, the input is taken from stdin. If arguments are provided, each specifies an InChannel, or the name of a file for input.

The RS variable defines a regular expression that determines a record separator, The default value of RS is the regular expression \r| |\r .

The fsubst function reads the file one record at a time.

For each record, the cases are evaluated in order. Each case defines a substitution from a substring matching the pattern to replacement text defined by the body.

Currently, there is only one option: g. If specified, each clause specifies a global replacement, and all instances of the pattern define a substitution. Otherwise, the substitution is applied only once.

Output can be redirected by redefining the stdout variable.

For example, the following program replaces all occurrences of an expression word. with its capitalized form.

    section
       stdout = $(fopen Subst.out, w)
       fsubst(Subst.in)
       case $"\<\([[:alnum:]]+\)\." g
          value $(capitalize $1).
       close(stdout)

  LEXER

The Lexer object defines a facility for lexical analysis, similar to the lex(1) and flex(1) programs.

In omake, lexical analyzers can be constructed dynamically by extending the Lexer class. A lexer definition consists of a set of directives specified with method calls, and set of clauses specified as rules.

For example, consider the following lexer definition, which is intended for lexical analysis of simple arithmetic expressions for a desktop calculator.

   lexer1. =
      extends $(Lexer)
      other: .
         eprintln(Illegal character: $* )
         lex()
      white: $"[[:space:]]+"
         lex()
      op: $"[-+*/()]"
         switch $*
         case +
            Token.unit($(loc), plus)
         case -
            Token.unit($(loc), minus)
         case *
            Token.unit($(loc), mul)
         case /
            Token.unit($(loc), div)
         case $"("
            Token.unit($(loc), lparen)
         case $")"
            Token.unit($(loc), rparen)
      number: $"[[:digit:]]+"
         Token.pair($(loc), exp, $(int $* ))
      eof: $"\'"
         Token.unit($(loc), eof)

This program defines an object lexer1 the extends the Lexer object, which defines lexing environment.

The remainder of the definition consists of a set of clauses, each with a method name before the colon; a regular expression after the colon; and in this case, a body. The body is optional, if it is not specified, the method with the given name should already exist in the lexer definition.

NB The clause that matches the longest prefix of the input is selected. If two clauses match the same input prefix, then the last one is selected. This is unlike most standard lexers, but makes more sense for extensible grammars.

The first clause matches any input that is not matched by the other clauses. In this case, an error message is printed for any unknown character, and the input is skipped. Note that this clause is selected only if no other clause matches.

The second clause is responsible for ignoring white space. If whitespace is found, it is ignored, and the lexer is called recursively.

The third clause is responsible for the arithmetic operators. It makes use of the Token object, which defines three fields: a loc field that represents the source location; a name; and a value.

The lexer defines the loc variable to be the location of the current lexeme in each of the method bodies, so we can use that value to create the tokens.

The Token.unit($(loc), name) method constructs a new Token object with the given name, and a default value.

The number clause matches nonnegative integer constants. The Token.pair($(loc), name, value) constructs a token with the given name and value.

Lexer object operate on InChannel objects. The method lexer1.lex-channel(channel) reads the next token from the channel argument.

  LEXER MATCHING

During lexical analysis, clauses are selected by longest match. That is, the clause that matches the longest sequence of input characters is chosen for evaluation. If no clause matches, the lexer raises a RuntimeException. If more than one clause matches the same amount of input, the first one is chosen for evaluation.

  EXTENDING LEXER DEFINITIONS

Suppose we wish to augment the lexer example so that it ignores comments. We will define comments as any text that begins with the string (*, ends with *), and comments may be nested.

One convenient way to do this is to define a separate lexer just to skip comments.

   lex-comment. =
      extends $(Lexer)
      level = 0
      other: .
         lex()
      term: $"[*][)]"
         if $(not $(eq $(level), 0))
            level = $(sub $(level), 1)
            lex()
      next: $"[(][*]"
         level = $(add $(level), 1)
         lex()
      eof: $"\'"
         eprintln(Unterminated comment)

This lexer contains a field level that keeps track of the nesting level. On encountering a (* string, it increments the level, and for *), it decrements the level if nonzero, and continues.

Next, we need to modify our previous lexer to skip comments. We can do this by extending the lexer object lexer1 that we just created.

   lexer1. +=
      comment: $"[(][*]"
         lex-comment.lex-channel($(channel))
         lex()

The body for the comment clause calls the lex-comment lexer when a comment is encountered, and continues lexing when that lexer returns.

  THREADING THE LEXER OBJECT

Clause bodies may also end with an export directive. In this case the lexer object itself is used as the returned token. If used with the Parser object below, the lexer should define the loc, name and value fields in each export clause. Each time the Parser calls the lexer, it calls it with the lexer returned from the previous lex invocation.

  PARSER

The Parser object provides a facility for syntactic analysis based on context-free grammars.

Parser objects are specified as a sequence of directives, specified with method calls; and productions, specified as rules.

For example, let's finish building the desktop calculator started in the Lexer example.

   parser1. =
      extends $(Parser)
      #
      # Use the main lexer
      #
      lexer = $(lexer1)
      #
      # Precedences, in ascending order
      #
      left(plus minus)
      left(mul div)
      right(uminus)
      #
      # A program
      #
      start(prog)
      prog: exp eof
         return $1
      #
      # Simple arithmetic expressions
      #
      exp: minus exp :prec: uminus
         neg($2)
      exp: exp plus exp
         add($1, $3)
      exp: exp minus exp
         sub($1, $3)
      exp: exp mul exp
         mul($1, $3)
      exp: exp div exp
         div($1, $3)
      exp: lparen exp rparen
         return $2

Parsers are defined as extensions of the Parser class. A Parser object must have a lexer field. The lexer is not required to be a Lexer object, but it must provide a lexer.lex() method that returns a token object with name and value fields. For this example, we use the lexer1 object that we defined previously.

The next step is to define precedences for the terminal symbols. The precedences are defined with the left, right, and nonassoc methods in order of increasing precedence.

The grammar must have at least one start symbol, declared with the start method.

Next, the productions in the grammar are listed as rules. The name of the production is listed before the colon, and a sequence of variables is listed to the right of the colon. The body is a semantic action to be evaluated when the production is recognized as part of the input.

In this example, these are the productions for the arithmetic expressions recognized by the desktop calculator. The semantic action performs the calculation. The variables $1, $2, ... correspond to the values associated with each of the variables on the right-hand-side of the production.

  CALLING THE PARSER

The parser is called with the $(parser1.parse-channel start, channel) or $(parser1.parse-file start, file) functions. The start argument is the start symbol, and the channel or file is the input to the parser.

  PARSING CONTROL

The parser generator generates a pushdown automation based on LALR(1) tables. As usual, if the grammar is ambiguous, this may generate shift/reduce or reduce/reduce conflicts. These conflicts are printed to standard output when the automaton is generated.

By default, the automaton is not constructed until the parser is first used.

The build(debug) method forces the construction of the automaton. While not required, it is wise to finish each complete parser with a call to the build(debug) method. If the debug variable is set, this also prints with parser table together with any conflicts.

The loc variable is defined within action bodies, and represents the input range for all tokens on the right-hand-side of the production.

  EXTENDING PARSERS

Parsers may also be extended by inheritance. For example, let's extend the grammar so that it also recognizes the << and >> shift operations.

First, we extend the lexer so that it recognizes these tokens. This time, we choose to leave lexer1 intact, instead of using the += operator.

   lexer2. =
      extends $(lexer1)
      lsl: $"<<"
         Token.unit($(loc), lsl)
      asr: $">>"
         Token.unit($(loc), asr)

Next, we extend the parser to handle these new operators. We intend that the bitwise operators have lower precedence than the other arithmetic operators. The two-argument form of the left method accomplishes this.

   parser2. =
      extends $(parser1)
      left(plus, lsl lsr asr)
      lexer = $(lexer2)
      exp: exp lsl exp
         lsl($1, $3)
      exp: exp asr exp
         asr($1, $3)

In this case, we use the new lexer lexer2, and we add productions for the new shift operations.

  GETTIMEOFDAY

   $(gettimeofday) : Float

The gettimeofday function returns the time of day in seconds since January 1, 1970.

SHELL FUNCTIONS

  ECHO

The echo function prints a string.

$(echo <args>) echo <args>

  JOBS

The jobs function prints a list of jobs.

jobs

  CD

The cd function changes the current directory.

    cd(dir)
       dir : Dir

The cd function also supports a 2-argument form:

    $(cd dir, e)
       dir : Dir
       e : expression

In the two-argument form, expression e is evaluated in the directory dir. The current directory is not changed otherwise.

The behavior of the cd function can be changed with the CDPATH variable, which specifies a search path for directories. This is normally useful only in the osh command interpreter.

    CDPATH : Dir Sequence

For example, the following will change directory to the first directory ./foo, ~/dir1/foo, ~/dir2/foo.

    CDPATH[] =
       .
       $(HOME)/dir1
       $(HOME)/dir2
    cd foo

  BG

The bg function places a job in the background.

bg <pid...>

  FG

The fg function brings a job to the foreground.

fg <pid...>

  STOP

The stop function suspends a job.

stop <pid...>

  WAIT

The wait function waits for a job to finish. If no process identifiers are given, the shell waits for all jobs to complete.

wait <pid...>

  KILL

The kill function signals a job.

kill [signal] <pid...>

  HISTORY

    $(history-index) : Int
    $(history) : String Sequence
    history-file : File
    history-length : Int

The history variables manage the command-line history in osh. They have no effect in omake.

The history-index variable is the current index into the command-line history. The history variable is the current command-line history.

The history-file variable can be redefined if you want the command-line history to be saved. The default value is ~/.omake/osh_history.

The history-length variable can be redefined to specify the maximum number of lines in the history that you want saved. The default value is 100.

PERVASIVES

Pervasives defines the objects that are defined in all programs. The following objects are defined.

  OBJECT

Parent objects: none.

The Object object is the root object. Every class is a subclass of Object.

It provides the following fields:

*   $(o.object-length): the number of fields and methods in the object.

*   $(o.object-mem <var>): returns true iff the <var> is a field or method of the object.

*   $(o.object-add <var>, <value>): adds the field to the object, returning a new object.

*   $(o.object-find <var>): fetches the field or method from the object; it is equivalent to $(o.<var>), but the variable can be non-constant.

*   $(o.object-map <fun>): maps a function over the object. The function should take two arguments; the first is a field name, the second is the value of that field. The result is a new object constructed from the values returned by the function.

*   o.object-foreach: the foreach form is equivalent to map, but with altered syntax.

   o.foreach(<var1>, <var2>)
      <body>

For example, the following function prints all the fields of an object o.

   PrintObject(o) =
      o.foreach(v, x)
         println($(v) = $(x))

The export form is valid in a foreach body. The following function collects just the field names of an object.

   FieldNames(o) =
      names =
      o.foreach(v, x)
         names += $(v)
         export
      return $(names)

  MAP

Parent objects: Object.

A Map object is a dictionary from values to values. The <key> values are restricted to simple values: integers, floating-point numbers, strings, files, directories, and arrays of simple values.

The Map object provides the following methods.

*   $(o.mem <key>): returns true iff the <key> is defined in the map.

*   $(o.add <key>, <value>): adds the field to the map, returning a new map.

*   $(o.find <key>): fetches the field from the map.

*   $(o.map <fun>): maps a function over the map. The function should take two arguments; the first is a field name, the second is the value of that field. The result is a new object constructed from the values returned by the function.

*   o.foreach: the foreach form is equivalent to map, but with altered syntax.

   o.foreach(<var1>, <var2>)
      <body>

For example, the following function prints all the fields of an object o.

   PrintObject(o) =
      o.foreach(v, x)
         println($(v) = $(x))

The export form is valid in a foreach body. The following function collects just the field names of the map.

   FieldNames(o) =
      names =
      o.foreach(v, x)
         names += $(v)
         export
      return $(names)

There is also simpler syntax when the key is a string. The table can be defined using definitions with the form $|key| (the number of pipe symbols | is allowed to vary).

    $|key 1| = value1
    $||key1|key2|| = value2    # The key is key1|key2
    X = $|key 1|               # Define X to be the value of field $|key 1|

The usual modifiers are also allowed. The expression $`|key| represents lazy evaluation of the key, and $,|key| is normal evaluation.

  NUMBER

Parent objects: Object.

The Number object is the parent object for integers and floating-point numbers.

  INT

Parent objects: Number.

The Int object represents integer values.

  FLOAT

Parent objects: Number.

The Float object represents floating-point numbers.

  SEQUENCE

Parent objects: Object.

The Sequence object represents a generic object containing sequential elements. It provides the following methods.

*   $(s.length): the number of elements in the sequence.

*   $(s.map <fun>): maps a function over the fields in the sequence. The function should take one argument. The result is a new sequence constructed from the values returned by the function.

*   s.foreach: the foreach form is equivalent to map, but with altered syntax.

   s.foreach(<var>)
      <body>

For example, the following function prints all the elements of the sequence.

   PrintSequence(s) =
      s.foreach(x)
         println(Elem = $(x))

The export form is valid in a foreach body. The following function counts the number of zeros in the sequence.

   Zeros(s) =
      count = $(int 0)
      s.foreach(v)
         if $(equal $(v), 0)
            count = $(add $(count), 1)
            export
         export
      return $(count)

  ARRAY

Parent objects: Sequence.

The Array is a random-access sequence. It provides the following additional methods.

*   $(s.nth <i>): returns element i of the sequence.

*   $(s.rev <i>): returns the reversed sequence.

  STRING

Parent objects: Array.

  FUN

Parent objects: Object.

The Fun object provides the following methods.

*   $(f.arity): the arity if the function.

  RULE

Parent objects: Object.

The Rule object represents a build rule. It does not currently have any methods.

  TARGET

Parent object: Object.

The Target object contains information collected for a specific target file.

*   target: the target file.

*   effects: the files that may be modified by a side-effect when this target is built.

*   scanner_deps: static dependencies that must be built before this target can be scanned.

*   static-deps: statically-defined build dependencies of this target.

*   build-deps: all the build dependencies for the target, including static and scanned dependencies.

*   build-values: all the value dependencies associated with the build.

*   build-commands: the commands to build the target.

The object supports the following methods.

*   find(file): returns a Target object for the given file. Raises a RuntimeException if the specified target is not part of the project.

*   find-optional(file): returns a Target object for the given file, or false if the file is not part of the project.

NOTE: the information for a target is constructed dynamically, so it is possible that the Target object for a node will contain different values in different contexts. The easiest way to make sure that the Target information is complete is to compute it within a rule body, where the rule depends on the target file, or the dependencies of the target file.

  NODE

Parent objects: Object.

The Node object is the parent object for files and directories. It supports the following operations.

*   $(node.stat): returns a stat object for the file. If the file is a symbolic link, the stat information is for the destination of the link, not the link itself.

*   $(node.lstat): returns a stat object for the file or symbolic link.

*   $(node.unlink): removes the file.

*   $(node.rename <file>): renames the file.

*   $(node.link <file>): creates a hard link <dst> to this file.

*   $(node.symlink <file>): create a symbolic link <dst> to this file.

*   $(node.chmod <perm>): change the permission of this file.

*   $(node.chown <uid>, <gid>): change the owner and group id of this file.

  FILE

Parent objects: Node.

The file object represents the name of a file.

  DIR

Parent objects: Node.

The Dir object represents the name of a directory.

  CHANNEL

Parent objects: Object.

A Channel is a generic IO channel. It provides the following methods.

*   $(o.close): close the channel.

  INCHANNEL

Parent objects: Channel.

A InChannel is an input channel. The variable stdin is the standard input channel.

It provides the following methods.

*   $(InChannel.fopen <file>): open a new input channel.

  OUTCHANNEL

Parent object: Channel.

A OutChannel is an output channel. The variables stdout and stderr are the standard output and error channels.

It provides the following methods.

*   $(OutChannel.fopen <file>): open a new output channel.

*   $(OutChannel.append <file>): opens a new output channel, appending to the file.

*   $(c.flush): flush the output channel.

*   $(c.print <string>): print a string to the channel.

*   $(c.println <string>): print a string to the channel, followed by a line terminator.

  LOCATION

Parent objects: Location.

The Location object represents a location in a file.

  POSITION

Parent objects: Position.

The Position object represents a stack trace.

  EXCEPTION

Parent objects: Object.

The Exception object is used as the base object for exceptions. It has no fields.

  RUNTIMEEXCEPTION

Parent objects: Exception.

The RuntimeException object represents an exception from the runtime system. It has the following fields.

*   position: a string representing the location where the exception was raised.

*   message: a string containing the exception message.

  SHELL

Parent objects: Object.

The Shell object contains the collection of builtin functions available as shell commands.

You can define aliases by extending this object with additional methods. All methods in this class are called with one argument: a single array containing an argument list.

*   echo

The echo function prints its arguments to the standard output channel.

*   jobs

The jobs method prints the status of currently running commands.

*   cd

The cd function changes the current directory. Note that the current directory follows the usual scoping rules. For example, the following program lists the files in the foo directory, but the current directory is not changed.

   section
      echo Listing files in the foo directory...
      cd foo
      ls
   echo Listing files in the current directory...
   ls

*   bg

The bg method places a job in the background. The job is resumed if it has been suspended.

*   fg

The fg method brings a job to the foreground. The job is resumed if it has been suspended.

*   stop

The stop method suspends a running job.

*   wait

The wait function waits for a running job to terminate. It is not possible to wait for a suspended job.

The job is not brought to the foreground. If the wait is interrupted, the job continues to run in the background.

*   kill

The kill function signal a job.

kill [signal] <pid...>.

The signals are either numeric, or symbolic. The symbolic signals are named as follows.

ABRT, ALRM, HUP, ILL, KILL, QUIT, SEGV, TERM, USR1, USR2, CHLD, STOP, TSTP, TTIN, TTOU, VTALRM, PROF.

*   exit

The exit function terminates the current session.

*   which, where

See the documentation for the corresponding functions.

*   rehash

Reset the search path.

*   history

Print the current command-line history.

*   Win32 functions.

Win32 doesn't provide very many programs for scripting, except for the functions that are builtin to the DOS cmd.exe. The following functions are defined on Win32 and only on Win32. On other systems, it is expected that these programs already exist.

    *   grep

           grep [-q] [-n] pattern files...

        The grep function calls the omake grep function.

By default, omake uses internal versions of the following commands: cp, mv, cat, rm, mkdir, chmod, test, find. If you really want to use the standard system versions of these commands, set the USE_SYSTEM_COMMANDS as one of the first definitions in your OMakeroot file.

*   mkdir

        mkdir [-m <mode>] [-p] files

    The mkdir function is used to create directories. The -verb+-m+ option can be used to specify the permission mode of the created directory. If the -p option is specified, the full path is created.

*   cp

*   mv

        cp [-f] [-i] [-v] src dst
        cp [-f] [-i] [-v] files dst
        mv [-f] [-i] [-v] src dst
        mv [-f] [-i] [-v] files dst

    The cp function copies a src file to a dst file, overwriting it if it already exists. If more than one source file is specified, the final file must be a directory, and the source files are copied into the directory.

    -f  Copy files forcibly, do not prompt.

    -i  Prompt before removing destination files.

    -v  Explain what is happening.

*   rm

       rm [-f] [-i] [-v] [-r] files
       rmdir [-f] [-i] [-v] [-r] dirs

    The rm function removes a set of files. No warnings are issued if the files do not exist, or if they cannot be removed.

    Options:

    -f  Forcibly remove files, do not prompt.

    -i  Prompt before removal.

    -v  Explain what is happening.

    -r  Remove contents of directories recursively.

*   chmod

        chmod [-r] [-v] [-f] mode files

    The chmod function changes the permissions on a set of files or directories. This function does nothing on Win32. The mode may be specified as an octal number, or in symbolic form [ugoa]*[-=][rwxXstugo]+. See the man page for chmod for details.

    Options:

    -r  Change permissions of all files in a directory recursively.

    -v  Explain what is happening.

    -f  Continue on errors.

*   cat

       cat files...

    The cat function prints the contents of the files to stdout

*   test

       test \emph{expression}
       \verb+[+ \emph{expression} +]+
       \verb+[ --help+
       \verb+[ --version+

    See the documentation for the test function.

*   find

       find \emph{expression}

    See the documentation for the find function.

BUILD FUNCTIONS

  OMAKEFLAGS

   OMakeFlags(options)
      options : String

The OMakeFlags function is used to set omake options from within OMakefiles. The options have exactly the same format as options on the command line.

For example, the following code displays the progress bar unless the VERBOSE environment variable is defined.

    if $(not $(defined-env VERBOSE))
        OMakeFlags(-S --progress)
        export

  OMAKEVERSION

   OMakeVersion(version1)
   OMakeVersion(version1, version2)
      version1, version2 : String

The OMakeVersion function is used for version checking in OMakefiles. It takes one or two arguments.

In the one argument form, if the omake version number is less than <version1>, then an exception is raised. In the two argument form, the version must lie between version1 and version2.

  CMP-VERSIONS
   $(cmp-versions version1, version2)
      version1, version2 : String

The cmp-versions\ functions can be used to compare arbitrary version strings. It returns 0 when the two version strings are equal, a negative number when the first string represents an earlier version, and a positive number otherwise.

  DEFINECOMMANDVARS

   DefineCommandVars()

The DefineCommandVars function redefines the variables passed on the commandline. Variables definitions are passed on the command line in the form name=value. This function is primarily for internal use by omake to define these variables for the first time.

THE OMAKEROOT FILE

The standard OMakeroot file defines the functions are rules for building standard projects.

  VARIABLES

ROOT
    The root directory of the current project.

CWD The current working directory (the directory is set for each OMakefile in the project).

EMPTY
    The empty string.

STDROOT
    The name of the standard installed OMakeroot file.

VERBOSE
    Whether certain commands should be verbose (false by default).

ABORT_ON_COMMAND_ERROR
    If set to true, the construction of a target should be aborted whenever one of the commands to build it fail. This defaults to true, and should normally be left that way.

SCANNER_MODE
     This variable should be defined as one of four values (defaults to enabled).

    enabled
        Allow the use of default .SCANNER rules. Whenever a rule does not specify a :scanner: dependency explicitly, try to find a .SCANNER with the same target name.

    disabled
        Never use default .SCANNER rules.

    warning
        Allow the use of default .SCANNER rules, but print a warning whenever one is selected.

    error
        Do not allow the use of default .SCANNER rules. If a rule does not specify a :scanner: dependency, and there is a default .SCANNER rule, the build will terminate abnormally.

  SYSTEM VARIABLES

INSTALL
    The command to install a program (install on Unix, cp on Win32).

PATHSEP
    The normal path separator (: on Unix, ; on Win32).

DIRSEP
    The normal directory separator (/ on Unix, \ on Win32).

EXT_LIB
    File suffix for a static library (default is .a on Unix, and .lib on Win32).

EXT_OBJ
    File suffix for an object file (default is .o on Unix, and .obj on Win32).

EXT_ASM
    File suffix for an assembly file (default is .s on Unix, and .asm on Win32).

EXE File suffix for executables (default is empty for Unix, and .exe on Win32 and Cygwin).

BUILDING C PROGRAMS

omake provides extensive support for building C programs.

  C CONFIGURATION VARIABLES

The following variables can be redefined in your project.

CC  The name of the C compiler (on Unix it defaults to gcc when gcc is present and to cc otherwise; on Win32 defaults to cl /nologo).

CXX The name of the C++ compiler (on Unix it defaults to gcc when gcc is present and to c++ otherwise; on Win32 defaults to cl /nologo).

CPP The name of the C preprocessor (defaults to cpp on Unix, and cl /E on Win32).

CFLAGS
    Compilation flags to pass to the C compiler (default empty on Unix, and /DWIN32 on Win32).

CXXFLAGS
    Compilation flags to pass to the C++ compiler (default empty on Unix, and /DWIN32 on Win32).

INCLUDES
    Additional directories that specify the search path to the C and C++ compilers (default is .). The directories are passed to the C and C++ compilers with the -I option. The include path with -I prefixes is defined in the PREFIXED_INCLUDES variable.

LIBS
    Additional libraries needed when building a program (default is empty).

AS  The name of the assembler (defaults to as on Unix, and ml on Win32).

ASFLAGS
    Flags to pass to the assembler (default is empty on Unix, and /c /coff on Win32).

AR  The name of the program to create static libraries (defaults to ar cq on Unix, and lib on Win32).

AROUT
    The option string that specifies the output file for AR.

LD  The name of the linker (defaults to ld on Unix, and cl on Win32).

LDFLAGS
    Options to pass to the linker (default is empty).

YACC
    The name of the yacc parser generator (default is yacc on Unix, empty on Win32).

LEX The name of the lex lexer generator (default is lex on Unix, empty on Win32).

  CGENERATEDFILES, LOCALCGENERATEDFILES
CGeneratedFiles(files)
LocalCGeneratedFiles(files)

The CGeneratedFiles and LocalCGeneratedFiles functions specify files that need to be generated before any C files are scanned for dependencies. For example, if config.h and inputs.h are both generated files, specify:
CGeneratedFiles(config.h inputs.h)

The CGeneratedFiles function is global --- its arguments will be generated before any C files anywhere in the project are scanned for dependencies. The LocalCGeneratedFiles function follows the normal scoping rules of OMake.

  STATICCLIBRARY

The StaticCLibrary builds a static library.

StaticCLibrary(<target>, <files>)

The <target> does not include the library suffix, and The <files> list does not include the object suffix. These are obtained from the EXT_LIB and EXT_OBJ variables.

This function returns the library filename.

The following command builds the library libfoo.a from the files a.o b.o c.o on Unix, or the library libfoo.lib from the files a.obj b.obj c.obj on Win32.

StaticCLibrary(libfoo, a b c)

  STATICCLIBRARYCOPY

The StaticCLibraryCopy function copies the static library to an install location.

StaticCLibraryCopy(<tag>, <dir>, <lib>)

The <tag> is the name of a target (typically a .PHONY target); the <dir> is the installation directory, and <lib> is the library to be copied (without the library suffix).

This function returns the filename of the library in the target directory.

For example, the following code copies the library libfoo.a to the /usr/lib directory.

StaticCLibraryCopy(install, /usr/lib, libfoo)

  STATICCLIBRARYINSTALL

The StaticCLibraryInstall function builds a library, and sets the install location in one step. It returns the filename of the library in the target directory.

StaticCLibraryInstall(<tag>, <dir>, <libname>, <files>)

StaticCLibraryInstall(install, /usr/lib, libfoo, a b c)

  STATICCOBJECT, STATICCOBJECTCOPY, STATICCOBJECTINSTALL

These functions mirror the StaticCLibrary, StaticCLibraryCopy, and StaticCLibraryInstall functions, but they build an object file (a .o file on Unix, and a .obj file on Win32).

  CPROGRAM

The CProgram function builds a C program from a set of object files and libraries.

CProgram(<name>, <files>)

The <name> argument specifies the name of the program to be built; the <files> argument specifies the files to be linked. The function returns the filename of the executable.

Additional options can be passed through the following variables.

CFLAGS
    Flags used by the C compiler during the link step.

LDFLAGS
    Flags to pass to the loader.

LIBS
    Additional libraries to be linked.

For example, the following code specifies that the program foo is to be produced by linking the files bar.o and baz.o and libraries libfoo.a.

section
   LIBS = libfoo$(EXT_LIB)
   CProgram(foo, bar baz)

  CPROGRAMCOPY

The CProgramCopy function copies a file to an install location.

CProgramCopy(<tag>, <dir>, <program>)

CProgramCopy(install, /usr/bin, foo)

  CPROGRAMINSTALL

The CProgramInstall function specifies a program to build, and a location to install, simultaneously.

CProgramInstall(<tag>, <dir>, <name>, <files>)

section
   LIBS = libfoo$(EXT_LIB)
   CProgramInstall(install, /usr/bin, foo, bar baz)

  CXXPROGRAM, CXXPROGRAMINSTALL

The CXXProgram and CXXProgramInstall functions are equivalent to their C counterparts, except that would use $(CXX) and $(CXXFLAGS) for linking instead of $(CC) and $(CFLAGS).

BUILDING OCAML PROGRAMS

  VARIABLES FOR OCAML PROGRAMS

The following variables can be redefined in your project.

USE_OCAMLFIND
    Whether to use the ocamlfind utility (default false\)

OCAMLC
    The OCaml bytecode compiler (default ocamlc.opt if it exists and USE_OCAMLFIND is not set, otherwise ocamlc).

OCAMLOPT
    The OCaml native-code compiler (default ocamlopt.opt if it exists and USE_OCAMLFIND is not set, otherwise ocamlopt).

CAMLP4
    The camlp4 preprocessor (default camlp4).

OCAMLLEX
    The OCaml lexer generator (default ocamllex).

OCAMLLEXFLAGS
    The flags to pass to ocamllex (default -q).

OCAMLYACC
    The OCaml parser generator (default ocamlyacc).

OCAMLDEP
    The OCaml dependency analyzer (default ocamldep).

OCAMLMKTOP
    The OCaml toploop compiler (default ocamlmktop).

OCAMLLINK
    The OCaml bytecode linker (default $(OCAMLC)).

OCAMLOPTLINK
    The OCaml native-code linker (default $(OCAMLOPT)).

OCAMLINCLUDES
    Search path to pass to the OCaml compilers (default .). The search path with the -I prefix is defined by the PREFIXED_OCAMLINCLUDES variable.

OCAMLFIND
    The ocamlfind utility (default ocamlfind if USE_OCAMLFIND is set, otherwise empty).

OCAMLFINDFLAGS
    The flags to pass to ocamlfind (default empty, USE_OCAMLFIND must be set).

OCAMLPACKS
    Package names to pass to ocamlfind (USE_OCAMLFIND must be set).

BYTE_ENABLED
    Flag indicating whether to use the bytecode compiler (default true, when no ocamlopt found, false otherwise).

NATIVE_ENABLED
    Flag indicating whether to use the native-code compiler (default true, when ocamlopt is found, false otherwise). Both BYTE_ENABLED and NATIVE_ENABLED can be set to true; at least one should be set to true.

  OCAML COMMAND FLAGS

The following variables specify additional options to be passed to the OCaml tools.

OCAMLDEPFLAGS
    Flags to pass to OCAMLDEP.

OCAMLPPFLAGS
    Flags to pass to CAMLP4.

OCAMLCFLAGS
    Flags to pass to the byte-code compiler (default -g).

OCAMLOPTFLAGS
    Flags to pass to the native-code compiler (default empty).

OCAMLFLAGS
    Flags to pass to either compiler (default -warn-error A).

OCAMLINCLUDES
    Include path (default .).

OCAML_BYTE_LINK_FLAGS
    Flags to pass to the byte-code linker (default empty).

OCAML_NATIVE_LINK_FLAGS
    Flags to pass to the native-code linker (default empty).

OCAML_LINK_FLAGS
    Flags to pass to either linker.

  LIBRARY VARIABLES

The following variables are used during linking.

OCAML_LIBS
    Libraries to pass to the linker. These libraries become dependencies of the link step.

OCAML_OTHER_LIBS
    Additional libraries to pass to the linker. These libraries are not included as dependencies to the link step. Typical use is for the OCaml standard libraries like unix or str.

OCAML_CLIBS
    C libraries to pass to the linker.

OCAML_LIB_FLAGS
    Extra flags for the library.

  OCAMLGENERATEDFILES, LOCALOCAMLGENERATEDFILES
OCamlGeneratedFiles(files)
LocalOCamlGeneratedFiles(files)

The OCamlGeneratedFiles and LocalOCamlGeneratedFiles functions specify files that need to be generated before any OCaml files are scanned for dependencies. For example, if parser.ml and lexer.ml are both generated files, specify:
OCamlGeneratedFiles(parser.ml lexer.ml)

The OCamlGeneratedFiles function is global --- its arguments will be generated before any OCaml files anywhere in the project are scanned for dependencies. The LocalOCamlGeneratedFiles function follows the normal scoping rules of OMake.

  OCAMLLIBRARY

The OCamlLibrary function builds an OCaml library.

OCamlLibrary(<libname>, <files>)

The <libname> and <files> are listed without suffixes.

Additional variables used by the function:

ABORT_ON_DEPENDENCY_ERRORS
    The linker requires that the files to be listed in dependency order. If this variable is true, the order of the files is determined by the command line, but omake will abort with an error message if the order is illegal. Otherwise, the files are sorted automatically.

This function returns the list of all the targets that it defines the rules for (including the $(name)$(EXT_LIB) file when NATIVE_ENABLED is set).

The following code builds the libfoo.cmxa library from the files foo.cmx and bar.cmx (if NATIVE_ENABLED is set), and libfoo.cma from foo.cmo and bar.cmo (if BYTE_ENABLED is set).

OCamlLibrary(libfoo, foo bar)

  OCAMLLIBRARYCOPY

The OCamlLibraryCopy function copies a library to an install location.

OCamlLibraryCopy(<tag>, <libdir>, <libname>, <interface-files>)

The <interface-files> specify additional interface files to be copied if the INSTALL_INTERFACES variable is true.

  OCAMLLIBRARYINSTALL

The OCamlLibraryInstall function builds a library and copies it to an install location in one step.

OCamlLibraryInstall(<tag>, <libdir>, <libname>, <files>)

  OCAMLPROGRAM

The OCamlProgram function builds an OCaml program. It returns the array with all the targets for which it have defined the rules ($(name)$(EXE) and $(name).run and/or $(name).opt, depending on the NATIVE_ENABLED and BYTE_ENABLED variables).

OCamlProgram(<name>, <files>)

Additional variables used:

OCAML_LIBS
    Additional libraries passed to the linker, without suffix. These files become dependencies of the target program.

OCAML_OTHER_LIBS
    Additional libraries passed to the linker, without suffix. These files do not become dependencies of the target program.

OCAML_CLIBS
    C libraries to pass to the linker.

OCAML_BYTE_LINK_FLAGS
    Flags to pass to the bytecode linker.

OCAML_NATIVE_LINK_FLAGS
    Flags to pass to the native code linker.

OCAML_LINK_FLAGS
    Flags to pass to both linkers.

  OCAMLPROGRAMCOPY

The OCamlProgramCopy function copies an OCaml program to an install location.

OCamlProgramCopy(<tag>, <bindir>, <name>)

Additional variables used:

NATIVE_ENABLED
    If NATIVE_ENABLED is set, the native-code executable is copied; otherwise the byte-code executable is copied.

  OCAMLPROGRAMINSTALL

The OCamlProgramInstall function builds a programs and copies it to an install location in one step.

OCamlProgramInstall(<tag>, <bindir>, <name>, <files>)

BUILDING LaTeX PROGRAMS

  CONFIGURATION VARIABLES

The following variables can be modified in your project.

LATEX
    The LaTeX command (default latex).

TETEX2_ENABLED
    Flag indicating whether to use advanced LaTeX options present in TeTeX v.2 (default value is determined the first time omake reads LaTeX.src and depends on the version of LaTeX you have installed).

LATEXFLAGS
    The LaTeX flags (defaults depend on the TETEX2_ENABLED variable)

BIBTEX
    The BibTeX command (default bibtex).

MAKEINDEX
    The command to build an index (default makeindex).

DVIPS
    The .dvi to PostScript converter (default dvips).

DVIPSFLAGS
    Flags to pass to dvips (default -t letter).

DVIPDFM
    The .dvi to .pdf converter (default dvipdfm).

DVIPDFMFLAGS
    Flags to pass to dvipdfm (default -p letter).

PDFLATEX
    The .latex to .pdf converter (default pdflatex).

PDFLATEXFLAGS
    Flags to pass to pdflatex (default is empty).

USEPDFLATEX
    Flag indicating whether to use pdflatex instead of dvipdfm to generate the .pdf document (default false).

  LATEXDOCUMENT

The LaTeXDocument produces a LaTeX document.

LaTeXDocument(<name>, <texfiles>)

The document <name> and <texfiles> are listed without suffixes. This function returns the filenames for the generated .ps and .pdf files.

Additional variables used:

TEXINPUTS
    The LaTeX search path (an array of directories, default is taken from the TEXINPUTS environment variable).

TEXDEPS
    Additional files this document depends on.

  TEXGENERATEDFILES, LOCALTEXGENERATEDFILES
TeXGeneratedFiles(files)
LocalTeXGeneratedFiles(files)

The TeXGeneratedFiles and LocalTeXGeneratedFiles functions specify files that need to be generated before any LaTeXfiles are scanned for dependencies. For example, if config.tex and inputs.tex are both generated files, specify:
TeXGeneratedFiles(config.tex inputs.tex)

The TeXGeneratedFiles function is global --- its arguments will be generated before any TeX files anywhere in the project are scanned for dependencies. The LocalTeXGeneratedFiles function follows the normal scoping rules of OMake.

  LATEXDOCUMENTCOPY

The LaTeXDocumentCopy copies the document to an install location.

LaTeXDocumentCopy(<tag>, <libdir>, <installname>, <docname>)

This function copies just the .pdf and .ps files.

  LATEXDOCUMENTINSTALL

The LaTeXDocumentInstall builds a document and copies it to an install location in one step.

LaTeXDocumentInstall(<tag>, <libdir>, <installname>, <docname>, <files>)

EXAMINING THE DEPENDENCY GRAPH

  DEPENDENCIES, DEPENDENCIES-ALL

   $(dependencies targets) : File Array
   $(dependencies-all targets) : File Array
   $(dependencies-proper targets) : File Array
      targets : File Array
   raises RuntimeException

The dependencies function returns the set of immediate dependencies of the given targets. This function can only be used within a rule body and all the arguments to the dependency function must also be dependencies of this rule. This restriction ensures that all the dependencies are known when this function is executed.

The dependencies-all function is similar, but it expands the dependencies recursively, returning all of the dependencies of a target, not just the immediate ones.

The dependencies-proper function returns all recursive dependencies, except the dependencies that are leaf targets. A leaf target is a target that has no dependencies and no build commands; a leaf target corresponds to a source file in the current project.

In all three functions, files that are not part of the current project are silently discarded.

One purpose of the dependencies-proper function is for ``clean'' targets. For example, one way to delete all intermediate files in a build is with a rule that uses the dependencies-proper. Note however, that the rule requires building the project before it can be deleted. For a shorter form, see the filter-proper-targets function.

    .PHONY: clean
    APP = ...     # the name of the target application
    clean: $(APP)
       rm $(dependencies-proper $(APP))

  TARGET
   $(target targets) : Rule Array
      targets : File Sequence
   raises RuntimeException

The target function returns the Target object associated with each of the targets. See the Target object for more information.

  RULE

The rule function is called whenever a build rule is defined. It is unlikely that you will need to redefine this function, except in very exceptional cases.

   rule(multiple, target, pattern, sources, options, body) : Rule
      multiple : String
      target   : Sequence
      pattern  : Sequence
      sources  : Sequence
      options  : Array
      body     : Body

The rule function is called when a rule is evaluated.

multiple
    A Boolean value indicating whether the rule was defined with a double colon ::.

target
    The sequence of target names.

pattern
    The sequence of patterns. This sequence will be empty for two-part rules.

sources
    The sequence of dependencies.

options
    An array of options. Each option is represented as a two-element array with an option name, and the option value.

body
    The body expression of the rule.

Consider the following rule.

   target: pattern: sources :name1: option1 :name2: option2
      expr1
      expr2

This expression represents the following function call, where square brackets are used to indicate arrays.

   rule(false, target, pattern, sources,
        [[:name1:, option1], [:name2:, option2]]
        [expr1; expr2])

REFERENCES

  SEE ALSO

omake(1), omake-quickstart(1), omake-options(1), omake-root(1), omake-language(1), omake-shell(1), omake-rules(1), omake-base(1), omake-system(1), omake-pervasives(1), osh(1), make(1)

  VERSION

Version: 0.9.6.9 of April 11, 2006.

  LICENSE AND COPYRIGHT

(C)2003-2006, Mojave Group, Caltech

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

  AUTHOR

Jason Hickey et. al..br Caltech 256-80
Pasadena, CA 91125, USA
Email: omake-devel@metaprl.org
WWW: http://www.cs.caltech.edu/~jyh