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Filtering with the Exim Mail Transfer Agent
*******************************************

The specifications of the Exim Mail Transfer Agent's filtering facility
is converted mechanically into Texinfo format from its original
marked-up source.  Some typographic representations are changed,
chapters and sections cannot be numbered, and Texinfo lacks the ability
to mark updated parts of the specification with change bars.

Because the chapters and sections are unnumbered, cross references are
set to their names. This makes the English a bit odd, with phrases like
`see section "Multiple personal mailboxes"' but it seemed very
cumbersome to change this to `see the section entitled "Multiple
personal mailboxes"' each time.

* Menu:

* Exim's interface to mail filtering::


File: exim_filter.info,  Node: Exim's interface to mail filtering,  Prev: Top,  Up: Top

Exim's interface to mail filtering
**********************************

Exim is a mail transfer agent for Unix systems. This document describes
the user interface to its in-built mail filtering facility, and is
copyright (c) University of Cambridge 2001. It corresponds to Exim
version 3.30.
------------------------------------------------------------------------


* Menu:

* Introduction::
* Testing a new filter file::
* Installing a filter file::
* Testing an installed filter file::
* Format of filter files::
* String expansion::
* Header variables::
* User variables::
* Significant deliveries::
* Filter commands::
* The add command::
* The deliver command::
* The save command::
* The pipe command::
* Mail commands::
* Logging commands::
* Other commands::
* Obeying commands conditionally::
* String testing conditions::
* Numeric testing conditions::
* Testing for personal mail::
* Testing for significant deliveries::
* Testing for error messages::
* Testing delivery status::
* Testing a list of addresses::
* Multiple personal mailboxes::
* Ignoring delivery errors::
* Examples of filter commands::
* More about string expansion::
* Expansion items::
* Expansion operators::
* Expansion conditions::
* Expansion variables::


File: exim_filter.info,  Node: Introduction,  Next: Testing a new filter file,  Prev: Exim's interface to mail filtering,  Up: Exim's interface to mail filtering

Introduction
============

Most Unix mail transfer agents (programs that deliver mail) permit
individual users to specify automatic forwarding of their mail, usually
by placing a list of forwarding addresses in a file called `.forward'
in their home directories.  Exim extends this facility by allowing the
forwarding instructions to be a set of rules rather than just a list of
addresses, in effect providing ``.forward' with conditions'. Operating
the set of rules is called filtering, and the file that contains them
is called a filter file.

The ability to use filtering has to be enabled by the system
administrator, and some of the individual facilities can be separately
enabled or disabled.  A local document should be provided to describe
exactly what has been enabled.  In the absence of this, consult your
system administrator.

It is important to realize that no deliveries are actually made while a
filter file is being processed. The result of filtering is a list of
destinations to which a message should be delivered - the deliveries
themselves take place later, along with all other deliveries for the
message. This means that it is not possible to test for successful
deliveries while filtering. It also means that duplicate addresses
generated by filtering are dropped, as with any other duplicate
addresses.

This document describes how to use a filter file and the format of its
contents. It is intended for use by end-users. How the system
administrator can set up and control the use of filtering is described
in the full Exim specification.


File: exim_filter.info,  Node: Testing a new filter file,  Next: Installing a filter file,  Prev: Introduction,  Up: Exim's interface to mail filtering

Testing a new filter file
=========================

Filter files, especially the more complicated ones, should always be
tested, as it is easy to make mistakes. Exim provides a facility for
preliminary testing of a filter file before installing it. This tests
the syntax of the file and its basic operation, and can also be used
with ordinary `.forward' files.

Because a filter can do tests on the content of messages, a test
message is required. Suppose you have a new filter file called
`new-filter' and a test message called `test-message'. Assuming that
Exim is installed with the conventional path name `/usr/lib/sendmail'
(some operating systems use `/usr/sbin/sendmail'), the following
command can be used:

     /usr/lib/sendmail -bf new-filter <test-message

The -bf option tells Exim that the following item on the command line
is the name of a filter file which is to be tested.  There is also a
-bF option, which is similar, but which is used for testing system
filter files, as opposed to user filter files, and which is therefore of
use only to the system administrator.

The test message is supplied on the standard input. If there are no
message-dependent tests in the filter, then an empty file can be used. A
supplied message must start with header lines or the `From' message
separator line which is found in many multi-message folder files. Note
that blank lines at the start terminate the header lines. A warning is
given if no headers are read.

The result of running this command, provided no errors are detected in
the filter file, is a list of the actions that Exim would try to take
if presented with the message for real. For example, the output

     Deliver message to: gulliver@lilliput.fict.example
     Save message to: /home/lemuel/mail/archive

means that one copy of the message would be sent to
"gulliver@lilliput.fict.example", and another would be added to the file
`/home/lemuel/mail/archive', if all went well.

The actions themselves are not attempted while testing a filter file in
this way; there is no check, for example, that any forwarding addresses
are valid.  If you want to know why a particular action is being taken,
add the -v option to the command. This causes Exim to output the
results of any conditional tests and to indent its output according to
the depth if nesting of "if" commands.  Further additional output from
a filter test can be generated by the "testprint" command, which is
described below.

When Exim is outputting a list of the actions it would take, if any text
strings are included in the output, non-printing characters therein are
converted to escape sequences. In particular, if any text string
contains a newline character, this is shown as `\n' in the testing
output.

When testing a filter in this way, Exim makes up an `envelope' for the
message.  The recipient is by default the user running the command, and
so is the sender, but the command can be run with the -f option to
supply a different sender.  For example,

     /usr/lib/sendmail -bf new-filter -f islington@neverwhere <test-message

Alternatively, if the -f option is not used, but the first line of the
supplied message is a `From' separator from a message folder file (not
the same thing as a `From:' header line), the sender is taken from
there. If -f is present, the contents of any `From' line are ignored.

The `return path' is the same as the envelope sender, unless the message
contains a `Return-path:' header, in which case it is taken from there.
You need not worry about any of this unless you want to test out
features of a filter file that rely on the sender address or the return
path.

It is possible to change the envelope recipient by specifying further
options.  The -bfd option changes the domain of the recipient address,
while the -bfl option changes the `local part', that is, the part
before the @ sign. An adviser could make use of these to test someone
else's filter file.

The -bfp and -bfs options specify the prefix or suffix for the local
part.  These are relevant only when support for multiple personal
mailboxes is implemented; see the description in section "Multiple
personal mailboxes" below.


File: exim_filter.info,  Node: Installing a filter file,  Next: Testing an installed filter file,  Prev: Testing a new filter file,  Up: Exim's interface to mail filtering

Installing a filter file
========================

A filter file is normally installed under the name `.forward' in your
home directory - it is distinguished from a conventional `.forward'
file by its first line (described below). However, the file name is
configurable, and some system administrators may choose to use some
different name or location for filter files.


File: exim_filter.info,  Node: Testing an installed filter file,  Next: Format of filter files,  Prev: Installing a filter file,  Up: Exim's interface to mail filtering

Testing an installed filter file
================================

Testing a filter file before installation cannot find every potential
problem; for example, it does not actually run commands to which
messages are piped.  Some `live' tests should therefore also be done
once a filter is installed.

If at all possible, test your filter file by sending messages from some
OTHER account. If you send a message to yourself from the filtered
account, and delivery fails, the error message will be sent back to the
same account, which may cause another delivery failure. It won't cause
an infinite sequence of such messages, because delivery failure
messages do not themselves generate further messages. However, it does
mean that the failure won't be returned to you, and also that the
postmaster will have to investigate the stuck message.

If you have to test a filter from the same account, then a sensible
precaution is to include the line

     if error_message then finish endif

as the first filter command, at least while testing. This causes
filtering to be abandoned for a delivery failure message, and since no
destinations are generated, the message goes on to get delivered to the
original address. Unless there is a good reason for not doing so, it is
recommended that the above test be left in all filter files.


File: exim_filter.info,  Node: Format of filter files,  Next: String expansion,  Prev: Testing an installed filter file,  Up: Exim's interface to mail filtering

Format of filter files
======================

Apart from leading white space, the first text in a filter file must be

     # Exim filter

This is what distinguishes it from a conventional `.forward' file.  If
the file does not have this initial line it is treated as a conventional
`.forward' file, both when delivering mail and when using the -bf
testing mechanism.  The white space in the line is optional, and any
capitalization may be used.  Further text on the same line is treated
as a comment. For example, you could have

     #   Exim filter   <<== do not edit or remove this line!

The remainder of the file is a sequence of filtering commands, which
consist of keywords and data values, separated by white space or line
breaks, except in the case of conditions for the `if' command, where
round brackets (parentheses) also act as separators. For example, in
the command

     deliver gulliver@lilliput.fict.example

the keyword is `deliver' and the data value is
`gulliver@lilliput.fict.example'. The commands are in free format, and
there are no special terminators. If the character # follows a
separator, then everything from # up to the next newline is ignored.
This provides a way of including comments in a filter file.

There are two ways in which a data value can be input:

   * If the text contains no white space then it can be typed verbatim.
     However, if it is part of a condition, it must also be free of
     round brackets (parentheses), as these are used for grouping in
     conditions.

   * Otherwise it must be enclosed in double quotation marks. In this
     case, the character \ (backslash) is treated as an `escape
     character' within the string, causing the following character or
     characters to be treated specially:

          \n       is replaced by a newline
          \r       is replaced by a carriage return
          \t       is replaced by a tab

     Backslash followed by up to three octal digits is replaced by the
     character specified by those digits, and \x followed by up to two
     hexacimal digits is treated similarly. Backslash followed by any
     other character is replaced by the second character, so that in
     particular, \" becomes " and \\ becomes \.  A data item enclosed
     in double quotes can be continued onto the next line by ending the
     first line with a backslash. Any leading white space at the start
     of the continuation line is ignored.

In addition to the escape character processing that occurs when strings
are enclosed in quotes, most data values are also subject to string
expansion (as described in the next section), in which case the
characters "$" and "\" are also significant.  This means that if a
single backslash is actually required in such a string, and the string
is also quoted, \\\\ has to be entered.


File: exim_filter.info,  Node: String expansion,  Next: Header variables,  Prev: Format of filter files,  Up: Exim's interface to mail filtering

String expansion
================

Most data values are expanded before use. Expansion consists of
replacing substrings beginning with "$" with other text. The full
expansion facilities are described from section "More about string
expansion" below onwards, but the most common case is the substitution
of a simple variable. For example, the substring

     $reply_address

is replaced by the address to which replies to the message should be
sent. If such a variable name is followed by a letter or digit or
underscore, it must be enclosed in curly brackets (braces), for example,

     ${reply_address}

If a `$' character is actually required in an expanded string, it must
be escaped with a backslash, and because backslash is also an escape
character in quoted input strings, it must be doubled in that case. The
following two examples illustrate the two cases:

     if $local_part contains \$ then ...
     if $local_part contains "\\$" then ...

The variable substitutions most likely to be useful in filter files are:

$home: The user's home directory.

$local_part: The part of the email address that precedes the @ sign -
normally the user's login name. If support for multiple personal
mailboxes is enabled (see section "Multiple personal mailboxes" below)
and a prefix or suffix for the local part was recognized, it is removed
from the string in this variable.

$local_part_prefix: If support for multiple personal mailboxes is
enabled (see section "Multiple personal mailboxes" below), and a local
part prefix was recognized, then this variable contains the prefix.
Otherwise it contains an empty string.

$local_part_suffix: If support for multiple personal mailboxes is
enabled (see section "Multiple personal mailboxes" below), and a local
part suffix was recognized, then this variable contains the suffix.
Otherwise it contains an empty string.

$message_body: The initial portion of the body of the message. By
default, up to 500 characters are read into this variable, but the
system administrator can configure this to some other value. Newlines
in the body are converted into single spaces.

$message_body_end: The final portion of the body of the message,
formatted and limited in the same way as $message_body.

$message_body_size: The size of the body of the message, in bytes.

$message_headers: The header lines of the message, concatenated into a
single string, with newline characters between them.

$message_id: The message's local identification string, which is unique
for each message handled by a single host.

$message_size: The size of the entire message, in bytes.

$original_local_part: When a top-level address is being processed, this
contains the same value as the variable $local_part. However, if an
address generated by an alias, forward, or filter file is being
processed, this variable contains the local part of the original
address.

$reply_address: The contents of the `Reply-to:' header, if the message
has one; otherwise the contents of the `From:' header. It is the
address to which normal replies to the message should be sent.

$return_path: The return path - that is, the sender field that will be
sent as part of the message's envelope, and which is the address to
which delivery errors are sent. In many cases, this has the same value
as $sender_address, but if, for example, an incoming message to a
mailing list has been expanded, then $return_path may contain the
address of the list maintainer instead.

$sender_address: The sender address that was received in the envelope
of the message. This is not necessarily the same as the contents of the
`From:' or `Sender:' header lines.  For delivery error messages
(`bounce messages') there is no sender address, and this variable is
empty.

$tod_full: A full version of the time and date, for example: Wed, 18 Oct
1995 09:51:40 +0100. The timezone is always given as a numerical offset
from GMT.

$tod_log: The time and date in the format used for writing Exim's log
files, for example: 1995-10-12 15:32:29.


File: exim_filter.info,  Node: Header variables,  Next: User variables,  Prev: String expansion,  Up: Exim's interface to mail filtering

Header variables
================

There is a special set of expansion variables containing the headers of
the message being processed. These variables have names beginning with
`$header_' followed by the name of the header, terminated by a colon.
For example,

     $header_from:
     $header_subject:

The whole item, including the terminating colon, is replaced by the
contents of the message header. If there is more than one header with
the same name, their contents are concatenated, with a single newline
character between them. The capitalization of the name following
`$header_' is not significant. Because any printing character except
colon may appear in the name of a message's header (this is a
requirement of RFC 822, the document that describes the format of a
mail message) curly brackets must not be used in this case, as they
will be taken as part of the header name. Two shortcuts are allowed in
naming header variables:

   * The initiating `$header_' can be abbreviated to `$h_'.

   * The terminating colon can be omitted if the next character is
     white space. The white space character is retained in the expanded
     string.  However, this is not recommended, because it makes it
     easy to forget the colon when it really is needed.

If the message does not contain a header of the given name, an empty
string is substituted. Thus it is important to spell the names of
headers correctly. Do not use `$header_Reply_to' when you really mean
`$header_Reply-to'.

You can test for the presence or absence of a header by means of the
`def' condition, which is described in section "Expansion conditions".


File: exim_filter.info,  Node: User variables,  Next: Significant deliveries,  Prev: Header variables,  Up: Exim's interface to mail filtering

User variables
==============

There are ten user variables with names $n0 - $n9 that can be
incremented by the "add" command (see section "The add command"). These
can be used for `scoring' messages in various ways. If Exim is
configured to run a `system filter' on every message, the values left
in these variables are copied into the variables $sn0 - $sn9 at the end
of the system filter, thus making them available to users' filter
files. How these values are used is entirely up to the individual
installation.


File: exim_filter.info,  Node: Significant deliveries,  Next: Filter commands,  Prev: User variables,  Up: Exim's interface to mail filtering

Significant deliveries
======================

When in the course of delivery a message is processed by a filter file,
what happens next, that is, after the whole filter file has been
processed, depends on whether the filter has set up any significant
deliveries or not. If there is at least one significant delivery, then
the filter is considered to have handled the entire delivery
arrangements for the current address, and no further processing of the
address takes place. If, however, no significant deliveries have been
set up, Exim continues processing the current address as if there were
no filter file, and typically sets up a delivery of a copy of the
message into a local mailbox. In particular, this happens in the
special case of a filter file containing only comments.

The delivery commands "deliver", "save", and "pipe" are by default
significant.  However, if such a command is preceded by the word
`unseen', then its delivery is not considered to be significant. In
contrast, other commands such as `mail' and `vacation' do not count as
significant deliveries unless preceded by the word `seen'.


File: exim_filter.info,  Node: Filter commands,  Next: The add command,  Prev: Significant deliveries,  Up: Exim's interface to mail filtering

Filter commands
===============

The filter commands which are described in subsequent sections are
listed below, with the section in which they are described in brackets:

     "add"              increment a user variable ("The add command")
     "deliver"          deliver to an email address ("The deliver command")
     "finish"           end processing ("Other commands")
     "if"               test condition(s) ("Obeying commands conditionally")
     "logfile"          define log file ("Logging commands")
     "logwrite"         write to log file ("Logging commands")
     "mail"             send a reply message ("Mail commands")
     "pipe"             pipe to a command ("The pipe command")
     "save"             save to a file ("The save command")
     "testprint"        print while testing ("Other commands")
     "vacation"         tailored form of "mail" ("Mail commands")

In addition, when Exim's filtering facilities are being used as a system
filter, the "fail", "freeze", and "headers" commands are available.
However, since they are usable only by the system administrator and not
by ordinary users, they are described in the main Exim specification
rather than in this document.


File: exim_filter.info,  Node: The add command,  Next: The deliver command,  Prev: Filter commands,  Up: Exim's interface to mail filtering

The add command
===============


          add <number> to <user variable>
     e.g. add 2 to n3

There are 10 user variables of this type, and their values can be
obtained by the normal expansion syntax (for example $n3) in other
commands. At the start of filtering, these variables all contain zero.
Both arguments of the "add" command are expanded before use, making it
possible to add variables to each other. Subtraction can be obtained by
adding negative numbers.


File: exim_filter.info,  Node: The deliver command,  Next: The save command,  Prev: The add command,  Up: Exim's interface to mail filtering

The deliver command
===================


          deliver <mail address>
     e.g. deliver "Dr Livingstone <David@somewhere.africa>"

This provides a forwarding operation. The message is sent on to the
given address, exactly as happens if the address had appeared in a
traditional `.forward' file. To deliver a copy of the message to your
normal mailbox, your login name can be given. Once an address has been
processed by the filtering mechanism, an identical generated address
will not be so processed again, so doing this does not cause a loop.

However, if you have a mail alias, you should not refer to it here. For
example, if the mail address `L.Gulliver' is aliased to `lg103' then all
references in Gulliver's `.forward' file should be to `lg103'. A
reference to the alias will not work for messages that are addressed to
that alias, since, like `.forward' file processing, aliasing is
performed only once on an address, in order to avoid looping.

Only a single address may be given to a "deliver" command, but multiple
occurrences of the command may be used to cause the message to be
delivered to more than one address. However, duplicate addresses are
discarded.

Following the new address, an optional second address, preceded by
`errors_to' may appear. This changes the address to which delivery
errors on the forwarded message will be sent. Instead of going to the
message's original sender, they go to this new address. For ordinary
users, the only value that is permitted for this address is the user
whose filter file is being processed.  For example, the user `lg103'
whose mailbox is in the domain "lilliput.example" could have a filter
file that contains

          deliver jon@elsewhere.example errors_to lg103@lilliput.example

Clearly, using this feature makes sense only in situations where some
(but not all) messages are being forwarded. In particular, bounce
messages must not be forwarded in this way, as this is likely to create
a mail loop if something goes wrong.


File: exim_filter.info,  Node: The save command,  Next: The pipe command,  Prev: The deliver command,  Up: Exim's interface to mail filtering

The save command
================


          save <file name>
     e.g. save $home/mail/bookfolder

This causes a copy of the message to be appended to the given file
(that is, the file is used as a mail folder).  More than one "save"
command may appear; each one causes a copy of the message to be written
to its argument file, provided they are different (duplicate "save"
commands are ignored).

If the file name does not start with a / character, then the contents
of the $home variable are prepended. The user must of course have
permission to write to the file, and the writing of the file takes
place in a process that is running as the user, under the user's
primary group. Any secondary groups to which the user may belong are
not normally taken into account, though the system administrator can
configure Exim to set them up. In addition, the ability to use this
command at all is controlled by the system administrator - it may be
forbidden on some systems. An optional mode value may be given after
the file name, for example,

          save /some/folder 0640

The value for the mode is interpreted as an octal number, even if it
does not begin with a zero. This makes it possible for users to
override the system-wide mode setting for file deliveries, which is
normally 600. If an existing file does not have the correct mode, it is
changed.

An alternative form of delivery may be enabled on your system, in which
each message is delivered into a new file in a given directory. If this
is the case, this functionality can be requested by giving the
directory name terminated by a slash after the "save" command, for
example

         save separated/messages/

There are several different formats for such deliveries; check with
your system administrator or local documentation to find out which (if
any) are available on your system. If this functionality is not
enabled, the use of a path name ending in a slash causes an error.


File: exim_filter.info,  Node: The pipe command,  Next: Mail commands,  Prev: The save command,  Up: Exim's interface to mail filtering

The pipe command
================


          pipe <command>
     e.g. pipe "$home/bin/countmail $sender_address"

This command causes a separate process to be run, and a copy of the
message is passed on its standard input. The process runs as the user,
under the user's primary group. Any secondary groups to which the user
may belong are not normally taken into account, though the system
administrator can configure Exim to set them up.  More than one "pipe"
command may appear; each one causes a copy of the message to be written
to its argument pipe, provided they are different (duplicate "pipe"
commands are ignored).

The command supplied to "pipe" is split up by Exim into a command name
and a number of arguments, delimited by white space except for
arguments enclosed in double quotes, in which case backslash is
interpreted as an escape, or in single quotes, in which case no
escaping is recognized. Note that as the whole command is normally
supplied in double quotes, a second level of quoting is required for
internal double quotes. For example:

          pipe "$home/myscript \"size is $message_size\""

String expansion is performed on the separate components after the line
has been split up, and the command is then run directly by Exim; it is
not run under a shell. Therefore, substitution cannot change the number
of arguments, nor can quotes, backslashes or other shell metacharacters
in variables cause confusion.

Documentation for some programs that are normally run via this kind of
pipe often suggest the the command start with

     IFS=" "

This is a shell command, and should not be present in Exim filter files,
since it does not normally run the command under a shell.

However, there is an option that the administrator can set to cause a
shell to be used. In this case, the entire command is expanded as a
single string and passed to the shell for interpretation. It is
recommended that this be avoided if at all possible, since it can lead
to problems when inserted variables contain shell metacharacters.

The default PATH set up for the command is determined by the system
administrator, usually containing at least "/usr/bin" so that common
commands are available without having to specify an absolute file name.
However, it is possible for the system administrator to restrict the
pipe facility so that the command name must not contain any /
characters, and must be found in one of the directories in the
configured PATH. It is also possible for the system administrator to
lock out the use of the "pipe" command altogether.

When the command is run, the following environment variables are set up:

     DOMAIN               the local domain of the address
     HOME                 your home directory
     LOCAL_PART           your login name
     LOGNAME              your login name
     MESSAGE_ID           the message's unique id
     PATH                 the command search path
     SENDER               the sender of the message
     SHELL                /bin/sh
     USER                 your login name

If you run a command that is a shell script, be very careful in your
use of data from the incoming message in the commands in your script.
RFC 822 is very generous in the characters that are legally permitted
to appear in mail addresses, and in particular, an address may begin
with a vertical bar or a slash. For this reason you should always use
quotes round any arguments that involve data from the message, like
this:

     /some/command "$SENDER"

so that inserted shell meta-characters do not cause unwanted effects.

The pipe command should return a zero completion code if all has gone
well.  Most non-zero codes are treated by Exim as indicating a failure
of the pipe.  This is treated as a delivery failure, causing the
message to be returned to its sender. However, there are some
completion codes which are treated as temporary errors. The message
remains on Exim's spool disc, and the delivery is tried again later,
though it will ultimately time out if the delivery failures go on too
long. The completion codes to which this applies can be specified by
the system administrator; the default values are 73 and 75.

The pipe command should not normally write anything to its standard
output or standard error file descriptors. If it does, whatever is
written is normally returned to the sender of the message as a delivery
error, though this action can be varied by the system administrator.


File: exim_filter.info,  Node: Mail commands,  Next: Logging commands,  Prev: The pipe command,  Up: Exim's interface to mail filtering

Mail commands
=============

There are two commands which cause the creation of a new mail message,
neither of which count as a significant delivery unless the command is
preceded by the word `seen'. This is a powerful facility, but it should
be used with care, because of the danger of creating infinite sequences
of messages. The system administrator can forbid the use of these
commands altogether.

To help prevent runaway message sequences, these commands have no
effect when the incoming message is a delivery error message, and
messages sent by this means are treated as if they were reporting
delivery errors. Thus they should never themselves cause a delivery
error message to be returned. The basic mail-sending command is

          mail [to <address-list>]
               [cc <address-list>]
               [bcc <address-list>]
               [from <address>]
               [reply_to <address>]
               [subject <text>]
               [text <text>]
               [[expand] file <filename>]
               [return message]
               [log <log file name>]
               [once <note file name>]
               [once_repeat <time interval>]

     e.g. mail text "Your message about $h_subject has been received"

As a convenience for use in one common case, there is also a command
called "vacation". It behaves in the same way as "mail", except that
the defaults for the `file', `log', `once', and `once_repeat' options
are

     expand file .vacation.msg
     log  .vacation.log
     once .vacation
     once_repeat 7d

respectively.  These are the same file names and repeat period used by
the traditional Unix "vacation" command. The defaults can be overridden
by explicit settings, but if a file name is given its contents are
expanded only if explicitly requested.  The "vacation" command is
normally used conditionally, subject to the "personal" condition (see
section "Testing for personal mail" below) so as not to send automatic
replies to non-personal messages from mailing lists or elsewhere.

For both commands, the key/value argument pairs can appear in any
order. At least one of `text' or `file' must appear (except with
`vacation'); if both are present, the text string appears first in the
message. If `expand' precedes `file', then each line of the file is
subject to string expansion as it is included in the message.

Several lines of text can be supplied to `text' by including the escape
sequence `\n' in the string where newlines are required. If the command
is output during filter file testing, newlines in the text are shown as
`\n'.

Note that the keyword for creating a `Reply-To:' header is "reply_to",
because Exim keywords may contain underscores, but not hyphens. If the
"from" keyword is present and the given address does not match the user
who owns the forward file, Exim normally adds a `Sender:' header to the
message, though it can be configured not to do this.

If no `to' argument appears, the message is sent to the address in the
`$reply_address' variable (see section "String expansion" above).  An
`In-Reply-To:' header is automatically included in the created message,
giving a reference to the message identification of the incoming
message.

If "return message" is specified, the incoming message that caused the
filter file to be run is added to the end of the message, subject to a
maximum size limitation.

If a log file is specified, a line is added to it for each message sent.

If a `once' file is specified, it is used to hold a database for
remembering who has received a message, and no more than one message is
ever sent to any particular address, unless `once_repeat' is set. This
specifies a time interval after which another copy of the message is
sent. The interval is specified as a sequence of numbers, each followed
by the initial letter of one of `seconds', `minutes', `hours', `days',
or `weeks'. For example,

     once_repeat 5d4h

causes a new message to be sent if 5 days and 4 hours have elapsed
since the last one was sent. There must be no white space in a time
interval.

Commonly, the file name specified for `once' is used as the base name
for direct-access (DBM) file operations. There are a number of
different DBM libraries in existence. Some operating systems provide
one as a default, but even in this case a different one may have been
used when building Exim. With some DBM libraries, specifying `once'
results in two files being created, with the suffixes `.dir' and `.pag'
being added to the given name. With some others a single file with the
suffix `.db' is used, or the name is used unchanged.

Using a DBM file for implementing the `once' feature means that the file
grows as large as necessary. This is not usually a problem, but some
system administrators want to put a limit on it. The facility can be
configured not to use a DBM file, but instead, to use a regular file
with a maximum size. The data in such a file is searched sequentially,
and if the file fills up, the oldest entry is deleted to make way for a
new one. This means that some correspondents may receive a second copy
of the message after an unpredictable interval. Consult your local
information to see if your system is configured this way.

More than one "mail" or "vacation" command may be obeyed in a single
filter run; they are all honoured, even when they are to the same
recipient.


File: exim_filter.info,  Node: Logging commands,  Next: Other commands,  Prev: Mail commands,  Up: Exim's interface to mail filtering

Logging commands
================

A log can be kept of actions taken by a filter file. This facility is
normally available in conventional configurations, but there are some
situations where it might not be. Also, the system administrator may
choose to disable it. Check your local information if in doubt.

Logging takes place while the filter file is being interpreted. It does
not queue up for later like the delivery commands. The reason for this
is so that a log file need be opened only once for several write
operations. There are two commands, neither of which constitutes a
significant delivery. The first defines a file to which logging output
is subsequently written:

          logfile <file name>
     e.g. logfile $home/filter.log

The file name may optionally be followed by a mode for the file, which
is used if the file has to be created. For example,

          logfile $home/filter.log 0644

The number is interpreted as octal, even if it does not begin with a
zero.  The default for the mode is 600. It is suggested that the
"logfile" command normally appear as the first command in a filter
file. Once "logfile" has been obeyed, the "logwrite" command can be
used to write to the log file:

          logwrite "<some text string>"
     e.g. logwrite "$tod_log $message_id processed"

It is possible to have more than one "logfile" command, to specify
writing to different log files in different circumstances. Writing
takes place at the end of the file, and a newline character is added to
the end of each string if there isn't one already there. Newlines can
be put in the middle of the string by using the `\n' escape sequence.
Lines from simultaneous deliveries may get interleaved in the file, as
there is no interlocking, so you should plan your logging with this in
mind. However, data should not get lost.

In earlier versions of Exim the "logwrite" command was called "log",
and this name remains available for backwards compatibility. However,
it is not possible to use the name "log" as a command name following a
"mail" command, because it will be interpreted as the "log" option of
that command.


File: exim_filter.info,  Node: Other commands,  Next: Obeying commands conditionally,  Prev: Logging commands,  Up: Exim's interface to mail filtering

Other commands
==============

The command `finish', which has no arguments, causes Exim to stop
interpreting the filter file. This is not a significant action unless
preceded by `seen'. A filter file containing only `seen finish' is a
black hole.

It is sometimes helpful to be able to print out the values of variables
when testing filter files. The command

          testprint <text>
     e.g. testprint "home=$home reply_address=$reply_address"

does nothing when mail is being delivered. However, when the filtering
code is being tested by means of the -bf option, the value of the
string is written to the standard output.

When Exim's filtering facilities are being used as a system filter, the
"fail" and "freeze" commands are available. However, since they are
usable only by the system administrator and not by ordinary users, they
are described in the main Exim specification rather than in this
document.


File: exim_filter.info,  Node: Obeying commands conditionally,  Next: String testing conditions,  Prev: Other commands,  Up: Exim's interface to mail filtering

Obeying commands conditionally
==============================

Most of the power of filtering comes from the ability to test
conditions and obey different commands depending on the outcome. The
`if' command is used to specify conditional execution, and its general
form is

     if    <condition>
     then  <commands>
     elif  <condition>
     then  <commands>
     else  <commands>
     endif

There may be any number of `elif' and `then' sections (including none)
and the `else' section is also optional. Any number of commands,
including nested `if' commands, may appear in any of the <commands>
sections.

Conditions can be combined by using the words `and' and `or', and round
brackets (parentheses) can be used to specify how several conditions
are to combine. Without brackets, `and' is more binding than `or'.  For
example,

     if
       $h_subject: contains "Make money" or
       $h_precedence: is "junk" or
       ($h_sender: matches ^\\d{8}@ and not personal) or
       $message_body contains "this is spam"
     then
       seen finish
     endif

A condition can be preceded by `not' to negate it, and there are also
some negative forms of condition that are more English-like.


File: exim_filter.info,  Node: String testing conditions,  Next: Numeric testing conditions,  Prev: Obeying commands conditionally,  Up: Exim's interface to mail filtering

String testing conditions
=========================

There are a number of conditions that operate on text strings, using
the words `begins', `ends', `is', `contains' and `matches'. If the
condition names are written in lower-case, the testing of letters is
done without regard to case; if they are written in upper-case (for
example, `CONTAINS') then the case of letters is significant.

          <text1> begins <text2>
          <text1> does not begin <text2>
     e.g. $header_from: begins "Friend@"

A `begins' test checks for the presence of the second string at the
start of the first, both strings having been expanded.

          <text1> ends <text2>
          <text1> does not end <text2>
     e.g. $header_from: ends "public.com"

An `ends' test checks for the presence of the second string at the end
of the first, both strings having been expanded.

          <text1> is <text2>
          <text1> is not <text2>
     e.g. $local_part_suffix is "-foo"

An `is' test does an exact match between the strings, having first
expanded both strings.

          <text1> contains <text2>
          <text1> does not contain <text2>
     e.g. $header_subject: contains "evolution"

A `contains' test does a partial string match, having expanded both
strings.

          <text1> matches <text2>
          <text2> does not match <text2>
     e.g. $sender_address matches "(Bill|John)@"

For a `matches' test, after expansion of both strings, the second one is
interpreted as a regular expression. Exim uses the PCRE regular
expression library, which provides regular expressions that are
compatible with Perl.

Care must be taken if you need a backslash in a regular expression,
because backslashes are interpreted as escape characters both by the
string expansion code and by Exim's normal string reading code. For
example, if you want to test the sender address for a domain ending in
`.com' the regular expression is

     \.com$

The backslash and dollar sign in that expression have to be escaped
when used in a filter command, as otherwise they would be interpreted
by the expansion code. Thus what you actually write is

     if $sender_address matches \\.com\$

However, if the expression is given in quotes (mandatory only if it
contains white space) you have to write

     if $sender_address matches "\\\\.com\\$"

with `\\\\' for a backslash and `\\$' for a dollar sign. Hence, if you
actually require the string `\$' in a regular expression that is given
in double quotes, you need to write `\\\\\\$'.

If the regular expression contains bracketed sub-expressions, then
numeric variable substitutions such as $1 can be used in the subsequent
actions after a successful match. If the match fails, the values of the
numeric variables remain unchanged. Previous values are not restored
after `endif' - in other words, only one set of values is ever
available. If the condition contains several sub-conditions connected
by `and' or `or', it is the strings extracted from the last successful
match that are available in subsequent actions. Numeric variables from
any one sub-condition are also available for use in subsequent
sub-conditions, since string expansion of a condition occurs just
before it is tested.


File: exim_filter.info,  Node: Numeric testing conditions,  Next: Testing for personal mail,  Prev: String testing conditions,  Up: Exim's interface to mail filtering

Numeric testing conditions
==========================

The following conditions are available for performing numerical tests:

          <number1> is above <number2>
          <number1> is not above <number2>
          <number1> is below <number2>
          <number1> is not below <number2>
     e.g. $message_size is not above 10k

The <number> arguments must expand to strings of digits, optionally
followed by one of the letters K or M (upper-case or lower-case) which
cause multiplication by 1024 and 1024x1024 respectively.


File: exim_filter.info,  Node: Testing for personal mail,  Next: Testing for significant deliveries,  Prev: Numeric testing conditions,  Up: Exim's interface to mail filtering

Testing for personal mail
=========================

A common requirement is to distinguish between incoming personal mail
and mail from a mailing list.  In particular, this test is normally
required for so-called `vacation messages'.  The condition

          personal

is a shorthand for

          $header_to: contains $local_part@$domain and
          $header_from: does not contain $local_part@$domain and
          $header_from: does not contain server@ and
          $header_from: does not contain daemon@ and
          $header_from: does not contain root@ and
          $header_subject: does not contain "circular" and
          $header_precedence: does not contain "bulk" and
          $header_precedence: does not contain "list" and
          $header_precedence: does not contain "junk"

The variable `$local_part' contains the local part of the mail address
of the user whose filter file is being run - it is normally your login
id. The `$domain' variable contains the mail domain. This condition
tests for the appearance of the current user in the `To:' header,
checks that the sender is not the current user or one of a number of
common daemons, and checks the content of the `Subject:' and
`Precedence:' headers.

If prefixes or suffixes are in use for local parts - something which
depends on the configuration of Exim (see section "Multiple personal
mailboxes" below) - then the first two tests above are also done with

     $local_part_prefix$local_part$local_part_suffix

instead of just $local_part. If the system is configured to rewrite
local parts of mail addresses, for example, to rewrite `dag46' as
`Dirk.Gently', then the rewritten form of the address is also used in
the tests.

This example shows the use of "personal" in a filter file that is
sending out vacation messages:

     if personal then
       mail
        to $reply_address
        subject "Re: $h_subject:"
        file $home/vacation/message
        once $home/vacation/once
        once_repeat 10d
     endif

It is quite common for people who have mail accounts on a number of
different systems to forward all their mail to one system, and in this
case a check for personal mail should test all their various mail
addresses. To allow for this, the "personal" condition keyword can be
followed by

     alias <address>

any number of times, for example

     personal alias smith@else.where alias jones@other.place

This causes messages containing the alias addresses in any places where
the local address is tested to be treated as personal.


File: exim_filter.info,  Node: Testing for significant deliveries,  Next: Testing for error messages,  Prev: Testing for personal mail,  Up: Exim's interface to mail filtering

Testing for significant deliveries
==================================

Whether or not any previously obeyed filter commands have resulted in a
significant delivery can be tested by the condition `delivered', for
example:

     if not delivered then save mail/anomalous endif


File: exim_filter.info,  Node: Testing for error messages,  Next: Testing delivery status,  Prev: Testing for significant deliveries,  Up: Exim's interface to mail filtering

Testing for error messages
==========================

The condition `error_message' is true if the incoming message is a mail
delivery error message. Putting the command

     if error_message then finish endif

at the head of your filter file is a useful insurance against things
going wrong in such a way that you cannot receive delivery error
reports, and is highly recommended.  Note that "error_message" is a
condition, not an expansion variable, and therefore is not preceded by
"$".


File: exim_filter.info,  Node: Testing delivery status,  Next: Testing a list of addresses,  Prev: Testing for error messages,  Up: Exim's interface to mail filtering

Testing delivery status
=======================

There are two conditions which are intended mainly for use in system
filter files, but which are available in users' filter files as well.
The condition `first_delivery' is true if this is the first attempt to
deliver the message, and false otherwise. In a user filter file it will
be false only if there was previously an error in the filter, or if a
delivery for the user failed owing to, for example, a quota error, or
forwarding to a remote address that was deferred for some reason.

The condition `manually_thawed' is true only if the message was
`frozen' for some reason, and was subsequently released by the system
administrator. It is unlikely to be of use in users' filter files.


File: exim_filter.info,  Node: Testing a list of addresses,  Next: Multiple personal mailboxes,  Prev: Testing delivery status,  Up: Exim's interface to mail filtering

Testing a list of addresses
===========================

There is a facility for looping through a list of addresses and
applying a condition to each of them. It takes the form

     foranyaddress <string> (<condition>)

where <string> is interpreted as a list of RFC 822 addresses, as in a
typical header line, and <condition> is any valid filter condition or
combination of conditions. The parentheses surrounding the condition
are mandatory, to delimit it from possible further sub-conditions of
the enclosing "if" command. Within the condition, the expansion
variable $thisaddress is set to the non-comment portion of each of the
addresses in the string in turn. For example, if the string is

     B.Simpson <bart@springfield>, lisa@springfield (his sister)

then $thisaddress would take on the values `bart@springfield' and
`lisa@springfield' in turn.

If there are no valid addresses in the list, the whole condition is
false. If the internal condition is true for any one address, the
overall condition is true and the loop ends. If the internal condition
is false for all addresses in the list, the overall condition is false.
This example tests for the presence of an eight-digit local part in any
address in a "To:" header:

     if foranyaddress $h_to: ( $thisaddress matches ^\\d{8}@ ) then ...

When the overall condition is true, the value of $thisaddress in the
commands that follow "then" is the last value it took on inside the
loop. At the end of the "if" command, its value is reset to what it was
before. It is best to avoid the use of multiple occurrences of
"foranyaddress", nested or otherwise, in a single "if" command, if the
value of $thisaddress is to be used afterwards, because it isn't always
clear what the value will be. Nested "if" commands should be used
instead.

Header lines can be joined together if a check is to be applied to more
than one of them. For example:

     if foranyaddress $h_to:,$h_cc: ....

scans through the addresses in both the "To:" and the "Cc:" headers.


File: exim_filter.info,  Node: Multiple personal mailboxes,  Next: Ignoring delivery errors,  Prev: Testing a list of addresses,  Up: Exim's interface to mail filtering

Multiple personal mailboxes
===========================

The system administrator can configure Exim so that users can set up
variants on their email addresses and handle them separately. Consult
your system administrator or local documentation to see if this
facility is enabled on your system, and if so, what the details are.

The facility involves the use of a prefix or a suffix on an email
address. For example, all mail addressed to "lg103-<something>" would
be the property of user "lg103", who could determine how it was to be
handled, depending on the value of <something>.

There are two possible ways in which this can be set up. The first
possibility is the use of multiple `.forward' files. In this case, mail
to "lg103-foo", for example, is handled by looking for a file called
".forward-foo" in "lg103's" home directory. If such a file does not
exist, delivery fails and the message is returned to its sender.

The alternative approach is to pass all messages through a single
`.forward' file, which must be a filter file in order to distinguish
between the different cases by referencing the variables
$local_part_prefix or $local_part_suffix, as in the final example in
section "Examples of filter commands" below. If the filter file does
not handle a prefixed or suffixed address, delivery fails and the
message is returned to its sender.

It is possible to configure Exim to support both schemes at once. In
this case, a specific ".forward-foo" file is first sought; if it is not
found, the basic `.forward' file is used.

The `personal' test (see section "Testing for personal mail") includes
prefixes and suffixes in its checking.


File: exim_filter.info,  Node: Ignoring delivery errors,  Next: Examples of filter commands,  Prev: Multiple personal mailboxes,  Up: Exim's interface to mail filtering

Ignoring delivery errors
========================

As was explained above, filtering just sets up addresses for delivery -
no deliveries are actually done while a filter file is active. If any
of the generated addresses subsequently suffers a delivery failure, an
error message is generated in the normal way. However, if the filter
command which sets up a delivery is preceded by the word `noerror',
then errors for that delivery, and any deliveries consequent on it
(that is, from alias, forwarding, or filter files it invokes) are
ignored.


File: exim_filter.info,  Node: Examples of filter commands,  Next: More about string expansion,  Prev: Ignoring delivery errors,  Up: Exim's interface to mail filtering

Examples of filter commands
===========================

Simple forwarding:

     # Exim filter
     deliver baggins@rivendell.middle.earth

Vacation handling using traditional means, assuming that the
".vacation.msg" and other files have been set up in your home directory:

     # Exim filter
     unseen pipe "/usr/ucb/vacation \"$local_part\""

Vacation handling inside Exim, having first created a file called
".vacation.msg" in your home directory:

     # Exim filter
     if personal then vacation endif

File some messages by subject:

     # Exim filter
     if $header_subject: contains "empire" or
        $header_subject: contains "foundation"
     then
        save $home/mail/f&e
     endif

Save all non-urgent messages by weekday:

     # Exim filter
     if $header_subject: does not contain "urgent" and
        $tod_full matches "^(...),"
     then
       save $home/mail/$1
     endif

Throw away all mail from one site, except from postmaster:

     # Exim filter
     if $reply_address contains "@spam.site" and
        $reply_address does not contain "postmaster@"
     then
        seen finish
     endif

Handle multiple personal mailboxes

     # Exim filter
     if $local_part_suffix is "-foo"
     then
       save $home/mail/foo
     elif $local_part_suffix is "-bar"
     then
       save $home/mail/bar
     endif


File: exim_filter.info,  Node: More about string expansion,  Next: Expansion items,  Prev: Examples of filter commands,  Up: Exim's interface to mail filtering

More about string expansion
===========================

The description which follows in the next section is an excerpt from
the full specification of Exim, except that it lists only those
expansion variables that are likely to be useful in filter files.

Expanded strings are copied verbatim from left to right except when a
dollar or backslash character is encountered. A dollar specifies the
start of a portion of the string which is interpreted and replaced as
described below.

An uninterpreted dollar can be included in the string by putting a
backslash in front of it - if the string appears in quotes, two
backslashes are required because the quotes themselves cause
interpretation of backslashes when the string is read in. A backslash
can be used to prevent any special character being treated specially in
an expansion, including itself.

A backslash followed by one of the letters `n', `r', or `t' is
recognized as an escape sequence for the character newline, carriage
return, or tab, respectively. A backslash followed by up to three octal
digits is recognized as an octal encoding for a single character, while
a backslash followed by `x' and up to two hexadecimal digits is a
hexadecimal encoding. A backslash followed by any other character
causes that character to be added to the output string uninterpreted.
These escape sequences are also recognized in quoted strings as they
are read in; their interpretation in expansions as well is useful for
unquoted strings and other cases such as looked-up strings that are then
expanded.


File: exim_filter.info,  Node: Expansion items,  Next: Expansion operators,  Prev: More about string expansion,  Up: Exim's interface to mail filtering

Expansion items
===============

The following items are recognized in expanded strings. White space may
be used between sub-items that are keywords or substrings enclosed in
braces inside an outer set of braces, to improve readability.  Within
braces, however, white space is significant.

     [(font color=blue)]______________________________________________________________[(/font)]
     
     $<variable name> or ${<variable name>}

Substitute the contents of the named variable, for example

     $local_part
     ${domain}

The second form can be used to separate the name from subsequent
alphanumeric characters. This form (using curly brackets) is available
only for variables; it does not apply to message headers. The names of
the variables are given in section "Expansion variables" below. If the
name of a non-existent variable is given, the expansion fails.

     [(font color=blue)]______________________________________________________________[(/font)]
     
     $header_<header name>: or $h_<header name>:

Substitute the contents of the named message header line, for example

     $header_reply-to:

The header names follow the syntax of RFC 822, which states that they
may contain any printing characters except space and colon.
Consequently, curly brackets do not terminate header names, and should
not be used to enclose them as if they were variables. Attempting to do
so causes a syntax error.

Upper-case and lower-case letters are synonymous in header names. If the
following character is white space, the terminating colon may be
omitted, but this is not recommended, because you may then forget it
when it is needed. When white space terminates the header name, it is
included in the expanded string.  If the message does not contain the
given header, the expansion item is replaced by an empty string. (See
the "def" condition in section "Expansion conditions" for a means of
testing for the existence of a header.)  If there is more than one
header with the same name, they are all concatenated to form the
substitution string, with a newline character between each of them.
However, if the length of this string exceeds 64K, any further headers
of the same name are ignored.

     [(font color=blue)]______________________________________________________________[(/font)]
     
     ${<op>:<string>}

The string is first itself expanded, and then the operation specified
by <op> is applied to it. For example,

     ${lc:$local_part}

A list of operators is given in section "Expansion operators" below. The
string starts with the first character after the colon, which may be
leading white space.

     [(font color=blue)]______________________________________________________________[(/font)]
     
     ${extract{<key>}{<string1>}{<string2>}{<string3>}}

The key and <string1> are first expanded separately. The key must not
consist entirely of digits. For the string, the result must be of the
form:

     <key1> = <value1>  <key2> = <value2> ...

where the equals signs and spaces are optional. If any of the values
contain white space, they must be enclosed in double quotes, and any
values that are enclosed in double quotes are subject to escape
processing as described in section "Format of filter files". The
expanded <string1> is searched for the value that corresponds to the
key. If it is found, <string2> is expanded, and replaces the whole
item; otherwise <string3> is used. During the expansion of <string2>
the variable $value contains the value that has been extracted.
Afterwards, it is restored to any previous value it might have had.

If {<string3>} is omitted, the item is replaced by an empty string if
the key is not found. If {<string2>} is also omitted, the value that
was looked up is used. Thus, for example, these two expansions are
identical, and yield `2001':

     ${extract{gid}{uid=1984 gid=2001}}
     ${extract{gid}{uid=1984 gid=2001}{$value}}

Instead of {<string3>} the word `fail' (not in curly brackets) can
appear, for example:

     ${extract{Z}{A=... B=...}{$value} fail }

{<string2>} must be present for `fail' to be recognized. When this
syntax is used, if the extraction fails, the entire expansion fails.
This causes processing of the filter file to fail, which either delays
delivery of the message, or causes the filter file to be ignored,
depending on how the administrator has configured Exim.

     [(font color=blue)]______________________________________________________________[(/font)]
     
     ${extract{<number>}{<separators>}{<string1>}{<string2>}{<string3>}}

The <number> argument must consist entirely of decimal digits. This is
what distinguishes this form of "extract" from the previous kind. It
behaves in the same way, except that, instead of extracting a named
field, it extracts from <string1> the field whose number is given as
the first argument. The first field is numbered one. If the number is
greater than the number of fields in the string, the result is the
expansion of <string3>, or the empty string if <string3> is not
provided.  If the number is zero, the entire string is returned. The
fields in the string are separated by any one of the characters in the
separator string. For example:

     ${extract{2}{:}{x:42:99:& Mailer::/bin/bash}}

yields `42'. Two successive separators mean that the field between them
is empty (for example, the fifth field above).

     [(font color=blue)]______________________________________________________________[(/font)]
     
     ${if <condition> {<string1>}{<string2>}}

If <condition> is true, <string1> is expanded and replaces the whole
item; otherwise <string2> is used. For example,

     ${if eq {$local_part}{postmaster} {yes}{no} }

The second string need not be present; if it is not and the condition
is not true, the item is replaced with nothing. Alternatively, the word
`fail' may be present instead of the second string (without any curly
brackets). In this case, the expansion is forced to fail if the
condition is not true. The available conditions are described in
section "Expansion conditions" below.

     [(font color=blue)]______________________________________________________________[(/font)]
     
     ${lookup{<key>} <search type> {<file>} {<string1>} {<string2>}}

     ${lookup <search type> {<query>} {<string1>} {<string2>}}

These items specify data lookups in files and databases, as discussed in
chapter "". The first form is used for single-key lookups, and the
second is used for query-style lookups. The <key>, <file>, and <query>
strings are expanded before use.

If there is any white space in a lookup item which is part of a filter
command, the lookup item must be enclosed in double quotes.  The use of
data lookups in users' filter files may be locked out by the system
administrator.

If the lookup succeeds, <string1> is expanded and replaces the entire
item.  During its expansion, the variable $value contains the data
returned by the lookup.  Afterwards it reverts to the value it had
previously (at the outer level it is empty).  If the lookup fails,
<string2> is expanded and replaces the entire item. If {<string2>} is
omitted, the replacement is null on failure. Alternatively, <string2>
can itself be a nested lookup, thus providing a mechanism for looking
up a default value when the original lookup fails.

If a nested lookup is used as part of <string1>, $value contains the
data for the outer lookup while the parameters of the second lookup are
expanded, and also while <string2> of the second lookup is expanded,
should the second lookup fail.

Instead of {<string2>} the word `fail' can appear, and in this case, if
the lookup fails, the entire expansion is forced to fail. If both
{<string1>} and {<string2>} are omitted, the result is the looked up
value in the case of a successful lookup, and nothing in the case of
failure.

For single-key lookups, the string `partial-' is permitted to precede
the search type in order to do partial matching, and * or *@ may follow
a search type to request default lookups if the key does not match (see
sections "" and "").

If a partial search is used, the variables $1 and $2 contain the wild
and non-wild parts of the key during the expansion of the replacement
text.  They return to their previous values at the end of the lookup
item.

This example looks up the postmaster alias in the conventional alias
file.

     ${lookup {postmaster} lsearch {/etc/aliases} {$value}}

This example uses NIS+ to look up the full name of the user
corresponding to the local part of an address, forcing the expansion to
fail if it is not found.

     "${lookup nisplus {[name=$local_part],passwd.org_dir:gcos} \
       {$value}fail}"

     [(font color=blue)]______________________________________________________________[(/font)]
     
     ${lookup{<key:subkey>} <search type> {<file>} {<string1>} {<string2>}}

This is just a syntactic variation for a single-key lookup, surrounded
by an "extract" item. It searches for <key> in the file as described
above for single-key lookups; if it succeeds, it extracts from the data
a subfield which is identified by the <subkey>. For example, if a line
in a linearly searched file contains

     alice: uid=1984 gid=2001

then expanding the string

     ${lookup{alice:uid}lsearch{<file name>}{$value}}

yields the string `1984'. If the subkey is not found in the looked up
data, then <string2>, if present, is expanded and replaces the entire
item.  Otherwise the replacement is null. The example above could
equally well be written like this:

     ${extract{uid}{${lookup{alice}lsearch{<file name>}}}}

and this is recommended, because this approach can also be used with
query-style lookups.

     [(font color=blue)]______________________________________________________________[(/font)]
     
     ${sg{<subject>}{<regex>}{<replacement>}}

This item works like Perl's substitution operator (s) with the global
(/g) option; hence its name. It takes three arguments: the subject
string, a regular expression, and a substitution string. For example

     ${sg{abcdefabcdef}{abc}{xyz}}

yields `xyzdefxyzdef'. Because all three arguments are expanded before
use, if any $ or \ characters are required in the regular expression or
in the substitution string, they have to be escaped. For example

     ${sg{abcdef}{^(...)(...)\$}{\$2\$1}}

yields `defabc', and

     ${sg{1=A 4=D 3=C}{(\\d+)=}{K\$1=}}

yields `K1=A K4=D K3=C'.

     [(font color=blue)]______________________________________________________________[(/font)]
     
     ${tr{<subject>}{<characters>}{<replacements>}}

This item does single-character translation on its subject string. The
second argument is a list of characters to be translated in the subject
string. Each matching character is replaced by the corresponding
character from the replacement list. For example

     ${tr{abcdea}{ac}{13}}

yields `1b3de1'. If there are duplicates in the second character
string, the last occurrence is used. If the third string is shorter
than the second, its last character is replicated. However, if it is
empty, no translation takes place.


File: exim_filter.info,  Node: Expansion operators,  Next: Expansion conditions,  Prev: Expansion items,  Up: Exim's interface to mail filtering

Expansion operators
===================

The following operations can be performed on portions of an expanded
string.  The substring is first expanded before the operation is
applied to it.

     [(font color=blue)]______________________________________________________________[(/font)]
     
     ${domain:<string>}

The string is interpreted as an RFC 822 address and the domain is
extracted from it. If the string does not parse successfully, the
result is empty.

     [(font color=blue)]______________________________________________________________[(/font)]
     
     ${escape:<string>}

If the string contains any non-printing characters, they are converted
to escape sequences starting with a backslash.

     [(font color=blue)]______________________________________________________________[(/font)]
     
     ${expand:<string>}

The "expand" operator causes a string to be expanded for a second time.
For example,

     ${expand:${lookup{$domain}dbm{/some/file}{$value}}}

first looks up a string in a file while expanding the operand for
"expand", and then re-expands what it has found.

     [(font color=blue)]______________________________________________________________[(/font)]
     
     ${hash_<n>_<m>:<string>}

The two items <n> and <m> are numbers. If <n> is greater than or equal
to the length of the string, the operator returns the string. Otherwise
it computes a new string of length <n> by applying a hashing function
to the string. The new string consists of characters taken from the
first <m> characters of the string

     abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQWRSTUVWXYZ0123456789

and if <m> is not present the value 26 is used, so that only lower case
letters appear. These examples:

     ${hash_3:monty}
     ${hash_5:monty}
     ${hash_4_62:monty python}

yield

     jmg
     monty
     fbWx

respectively. The abbreviation "h" can be used instead of "hash".

     [(font color=blue)]______________________________________________________________[(/font)]
     
     ${nhash_<n>:<string>}

The string is processed by a hash function which returns a numeric
value in the range 0-<n>-1.

     [(font color=blue)]______________________________________________________________[(/font)]
     
     ${nhash_<n>_<m>:<string>}

The string is processed by a div/mod hash function which returns two
numbers, separated by a slash, in the ranges 0-<n>-1 and 0-<m>-1,
respectively. For example,

     ${nhash_8_64:supercalifragilisticexpialidocious}

returns the string `6/33'.

     [(font color=blue)]______________________________________________________________[(/font)]
     
     ${md5:<string>}

The "md5" operator computes the MD5 hash value of the string, and
returns it as a 32-digit hexadecimal number.

     [(font color=blue)]______________________________________________________________[(/font)]
     
     ${lc:<string>}

This forces the letters in the string into lower-case, for example:

     ${lc:$local_part}

     [(font color=blue)]______________________________________________________________[(/font)]
     
     ${uc:<string>}

This forces the letters in the string into upper-case.

     ${length_<number>:<string>}

The "length" operator can be used to extract the initial portion of a
string.  It is followed by an underscore and the number of characters
required. For example

     ${length_50:$message_body}

The result of this operator is either the first <number> characters or
the whole string, whichever is the shorter. The abbreviation "l" can be
used instead of "length".

     [(font color=blue)]______________________________________________________________[(/font)]
     
     ${local_part:<string>}

The string is interpreted as an RFC 822 address and the local part is
extracted from it. If the string does not parse successfully, the
result is empty.

     ${mask:<IP address>/<bit count>}

If the form of the string to be operated on is not an IP address
followed by a slash and an integer, the expansion fails. Otherwise,
this operator converts the IP address to binary, masks off the least
significant bits according to the bit count, and converts the result
back to text, with mask appended. For example,

     ${mask:10.111.131.206/28}

returns the string `10.111.131.192/28'. Since this operation is
expected to be mostly used for looking up masked addresses in files,
the result for an IPv6 address uses fullstops (periods) to separate
components instead of colons, because colon terminates a key string in
lsearch files. So, for example,

     ${mask:5f03:1200:836f:0a00:000a:0800:200a:c031/99}

returns the string

     5f03.1200.836f.0a00.000a.0800.2000.0000/99

Letters in IPv6 addresses are always output in lower case.

     [(font color=blue)]______________________________________________________________[(/font)]
     
     ${quote:<string>}

The "quote" operator puts its argument into double quotes if it contains
anything other than letters, digits, underscores, full stops (periods),
and hyphens. Any occurrences of double quotes and backslashes are
escaped with a backslash. For example,

     ${quote:ab"*"cd}

becomes

     "ab\"*\"cd"

The place where this is useful is when the argument is a substitution
from a variable or a message header.

     [(font color=blue)]______________________________________________________________[(/font)]
     
     ${quote_<lookup-type>:<string>}

This operator applies lookup-specific quoting rules to the string. Each
query-style lookup type has its own quoting rules which are described
with the lookups in chapter "". For example,

     ${quote_ldap:two + two}

returns `two%20%5C+%20two'. For single-key lookup types, no quoting is
necessary and this operator yields an unchanged string.

     [(font color=blue)]______________________________________________________________[(/font)]
     
     ${rxquote:<string>}

The "rxquote" operator inserts a backslash before any non-alphanumeric
characters in its argument. This is useful when substituting the values
of variables or headers inside regular expressions.

     [(font color=blue)]______________________________________________________________[(/font)]
     
     ${substr_<start>_<length>:<string>}

The "substr" operator can be used to extract more general substrings
than "length". It is followed by an underscore and the starting offset,
then a second underscore and the length required. For example

     ${substr_3_2:$local_part}

If the starting offset is greater than the string length the result is
the null string; if the length plus starting offset is greater than the
string length, the result is the right-hand part of the string,
starting from the given offset. The first character in the string has
offset zero. The abbreviation "s" can be used instead of "substr".

The "substr" expansion operator can take negative offset values to count
from the righthand end of its operand. The last character is offset -1,
the second-last is offset -2, and so on. Thus, for example,

     ${substr_-5_2:1234567}

yields `34'. If the absolute value of a negative offset is greater than
the length of the string, the substring starts at the beginning of the
string, and the length is reduced by the amount of overshoot. Thus, for
example,

     ${substr_-5_2:12}

yields an empty string, but

     ${substr_-3_2:12}

yields `1'.

If the second number is omitted from "substr", the remainder of the
string is taken if the offset was positive. If it was negative, all
characters in the string preceding the offset point are taken. For
example, an offset of -1 and no length yields all but the last
character of the string.


File: exim_filter.info,  Node: Expansion conditions,  Next: Expansion variables,  Prev: Expansion operators,  Up: Exim's interface to mail filtering

Expansion conditions
====================

The following conditions are available for testing by the "${if"
construct while expanding strings:

     [(font color=blue)]______________________________________________________________[(/font)]
     
     !<condition>

Preceding any condition with an exclamation mark negates the result of
the condition.

     <symbolic operator> {<string1>}{<string2>}

There are a number of symbolic operators for doing numeric comparisons.
They are:

     =        equal
     ==       equal
     >        greater
     >=       greater or equal
     <        less
     <=       less or equal

For example,

     ${if >{$message_size}{10M} ...

Note that the general negation operator provides for inequality testing.
The two strings must take the form of optionally signed decimal
integers, optionally followed by one of the letters `K' or `M' (in
either upper or lower case), signifying multiplication by 1024 or
1024*1024, respectively.

     [(font color=blue)]______________________________________________________________[(/font)]
     
     def:<variable name>

The "def" condition must be followed by the name of one of the expansion
variables defined in section "Expansion variables".  The condition is
true if the named expansion variable does not contain the empty string,
for example

     ${if def:sender_ident {from $sender_ident}}

Note that the variable name is given without a leading "$" character.
If the variable does not exist, the expansion fails.

     [(font color=blue)]______________________________________________________________[(/font)]
     
     def:header_<header name>:  or  def:h_<header name>:

This condition is true if a message is being processed and the named
header exists in the message. For example,

     ${if def:header_reply-to:{$h_reply-to:}{$h_from:}}

Note that no "$" appears before "header_" or "h_" in the condition, and
that header names must be terminated by colons if white space does not
follow.

     [(font color=blue)]______________________________________________________________[(/font)]
     
     exists {<file name>}

The substring is first expanded and then interpreted as an absolute
path.  The condition is true if the named file (or directory) exists.
The existence test is done by calling the "stat()" function.  The use
of the "exists" test in users' filter files may be locked out by the
system administrator.

     eq {<string1>}{<string2>}

The two substrings are first expanded. The condition is true if the two
resulting strings are identical, including the case of letters.

     [(font color=blue)]______________________________________________________________[(/font)]
     
     match {<string1>}{<string2>}

The two substrings are first expanded. The second is then treated as a
regular expression and applied to the first. Because of the
pre-expansion, if the regular expression contains dollar, or backslash
characters, they must be escaped with backslashes. Care must also be
taken if the regular expression contains braces (curly brackets). A
closing brace must be escaped so that it is not taken as a premature
termination of <string2>. It does no harm to escape opening braces, but
this is not strictly necessary. For example,

     ${if match {$local_part}{^\\d\{3\}} ...

If the whole expansion string is in double quotes, further escaping of
backslashes is also required.

The condition is true if the regular expression match succeeds. At the
start of an "if" expansion the values of the numeric variable
substitutions $1 etc.  are remembered. Obeying a "match" condition that
succeeds causes them to be reset to the substrings of that condition
and they will have these values during the expansion of the success
string. At the end of the "if" expansion, the previous values are
restored. After testing a combination of conditions using "or", the
subsequent values of the numeric variables are those of the condition
that succeeded.

     [(font color=blue)]______________________________________________________________[(/font)]
     
     pam {<string1>:<string2>:...}

"Pluggable Authentication Modules"
(http://www.kernel.org/pub/linux/libs/pam/) are a facility which is
available in the latest releases of Solaris and in some GNU/Linux
distributions. The Exim support, which is intended for use in
conjunction with the SMTP AUTH command, is available only if Exim is
compiled with

     SUPPORT_PAM=yes

in `Local/Makefile'. You probably need to add -lpam to EXTRALIBS, and
in some releases of GNU/Linux -ldl is also needed.

The argument string is first expanded, and the result must be a
colon-separated list of strings. The PAM module is initialized with the
service name `exim' and the user name taken from the first item in the
colon-separated data string (i.e. <string1>). The remaining items in
the data string are passed over in response to requests from the
authentication function. In the simple case there will only be one
request, for a password, so the data will consist of just two strings.

There can be problems if any of the strings are permitted to contain
colon characters. In the usual way, these have to be doubled to avoid
being taken as separators. If the data is being inserted from a
variable, the "sg" expansion item can be used to double any existing
colons. For example, the configuration of a LOGIN authenticator might
contain this setting:

     server_condition = ${if pam{$1:${sg{$2}{:}{::}}}{yes}{no}}

     [(font color=blue)]______________________________________________________________[(/font)]
     
     first_delivery

This condition, which has no data, is true during a message's first
delivery attempt. It is false during any subsequent delivery attempts.

     [(font color=blue)]______________________________________________________________[(/font)]
     
     queue_running

This condition, which has no data, is true during delivery attempts
that are initiated by queue-runner processes, and false otherwise.

     [(font color=blue)]______________________________________________________________[(/font)]
     
     or {{<cond1>}{<cond2>}...}

The sub-conditions are evaluated from left to right. The condition is
true if any one of the sub-conditions is true.  For example,

     ${if or {{eq{$local_part}{spqr}}{eq{$domain}{testing.com}}}...

When a true sub-condition is found, the following ones are parsed but
not evaluated. If there are several `match' sub-conditions the values
of the numeric variables afterwards are taken from the first one that
succeeds.

     [(font color=blue)]______________________________________________________________[(/font)]
     
     and {{<cond1>}{<cond2>}...}

The sub-conditions are evaluated from left to right. The condition is
true if all of the sub-conditions are true.  If there are several
`match' sub-conditions, the values of the numeric variables afterwards
are taken from the last one.  When a false sub-condition is found, the
following ones are parsed but not evaluated.

Note that "and" and "or" are complete conditions on their own, and
precede their lists of sub-conditions. Each sub-condition must be
enclosed in braces within the overall braces that contain the list. No
repetition of "if" is used.


File: exim_filter.info,  Node: Expansion variables,  Prev: Expansion conditions,  Up: Exim's interface to mail filtering

Expansion variables
===================

This list of expansion variable substitutions contains those that are
likely to be of use in filter files. Others that are not relevant at
filtering time, or are of interest only to the system administrator,
are omitted.

$0, $1, etc: When a "matches" expansion condition succeeds, these
variables contain the captured substrings identified by the regular
expression during subsequent processing of the success string of the
containing "if" expansion item. They may also be set externally by some
other matching process which precedes the expansion of the string. For
example, the commands available in Exim filter files include an "if"
command with its own regular expression matching condition.

$body_linecount: When a message is being received or delivered, this
variable contains the number of lines in the message's body.

 aller_gid: The group id under which the process that called Exim was
running.
This is not the same as the group id of the originator of a message
(see $originator_gid). If Exim re-execs itself, this variable in the new
incarnation normally contains the Exim gid.

  aller_uid: The user id under which the process that called Exim was
running.
This is not the same as the user id of the originator of a message (see
$originator_uid). If Exim re-execs itself, this variable in the new
incarnation normally contains the Exim uid.

     ompile_date: The date on which the Exim binary was compiled.
 ompile_number: The building process for Exim keeps a count of the number
of
times it has been compiled. This serves to distinguish different
compilations of the same version of the program.

$domain: When an address is being directed, routed, or delivered on its
own, this variable contains the domain. In particular, it is set during
user filtering, but not during system filtering, since a message may
have many recipients and the system filter is called just once.

$home: This is set to the user's home directory when user filtering is
configured in the normal way.  When running a filter test via the -bf
option, $home is set to the value of the environment variable HOME.

$local_part: When an address is being directed, routed, or delivered on
its own, this variable contains the local part. If a local part prefix
or suffix has been recognized, it is not included in the value.

$local_part_prefix: When an address is being directed or delivered
locally, and a specific prefix for the local part was recognized, it is
available in this variable. Otherwise it is empty.

$local_part_suffix: When an address is being directed or delivered
locally, and a specific suffix for the local part was recognized, it is
available in this variable. Otherwise it is empty.

$message_body: This variable contains the initial portion of a message's
body while it is being delivered, and is intended mainly for use in
filter files. The maximum number of characters of the body that are
used is set by the "message_body_visible" configuration option; the
default is 500. Newlines are converted into spaces to make it easier to
search for phrases that might be split over a line break.

$message_body_end: This variable contains the final portion of a
message's body while it is being delivered. The format and maximum size
are as for $message_body.

$message_body_size: When a message is being received or delivered, this
variable contains the size of the body in bytes. The count starts from
the character after the blank line that separates the body from the
header.  Newlines are included in the count. See also $message_size and
$body_linecount.

$message_headers: This variable contains a concatenation of all the
header lines when a message is being processed. They are separated by
newline characters.

$message_id: When a message is being received or delivered, this
variable contains the unique message id which is used by Exim to
identify the message.

$message_precedence: When a message is being delivered, the value of any
"Precedence:" header is made available in this variable. If there is no
such header, the value is the null string.

$message_size: When a message is being received or delivered, this
variable contains its size in bytes. In most cases, the size includes
those headers that were received with the message, but not those (such
as "Envelope-to:") that are added to individual deliveries as they are
written.  See also $message_body_size and $body_linecount.

$n0 - $n9: These variables are counters that can be incremented by means
of the "add" command in filter files.

$original_domain: When a top-level address is being processed for
delivery, this contains the same value as $domain. However, if a
`child' address (for example, generated by an alias, forward, or filter
file) is being processed, this variable contains the domain of the
original address.  This differs from $parent_domain when there is more
than one level of aliasing or forwarding.

$original_local_part: When a top-level address is being processed for
delivery, this contains the same value as $local_part. However, if a
`child' address (for example, generated by an alias, forward, or filter
file) is being processed, this variable contains the local part of the
original address.  This differs from $parent_local_part when there is
more than one level of aliasing or forwarding.

$originator_gid: The value of $caller_gid that was set when the message
was received. For messages received via the command line, this is the
gid of the sending user. For messages received by SMTP over TCP/IP,
this is normally the gid of the Exim user.

$originator_uid: The value of $caller_uid that was set when the message
was received. For messages received via the command line, this is the
uid of the sending user. For messages received by SMTP over TCP/IP,
this is normally the uid of the Exim user.

$parent_domain: This variable is empty, except when a `child' address
(generated by aliasing or forwarding, for example) is being processed,
in which case it contains the domain of the immediately preceding
parent address.

$parent_local_part: This variable is empty, except when a `child'
address (generated by aliasing or forwarding, for example) is being
processed, in which case it contains the local part of the immediately
preceding parent address.

$primary_hostname: The value set in the configuration file, or read by
the "uname()" function.

$qualify_domain: The value set for this option in the configuration
file.

$qualify_recipient: The value set for this option in the configuration
file, or if not set, the value of $qualify_domain.

$received_protocol: When a message is being processed, this variable
contains the name of the protocol by which it was received.

$reply_address: When a message is being processed, this variable
contains the contents of the "Reply-To:" header line if one exists, or
otherwise the contents of the "From:" header line.  However, if the
message contains a set of `Resent-' header lines, their contents are
used in preference.

$return_path: When a message is being delivered, this variable contains
the return path - the sender field that will be sent as part of the
envelope. It is not enclosed in <> characters. In many cases,
$return_path has the same value as $sender_address, but if, for
example, an incoming message to a mailing list has been expanded by a
director which specifies a specific address for delivery error
messages, $return_path contains the new error address, while
$sender_address contains the original sender address that was received
with the message.

$sender_address: When a message is being processed, this variable
contains the sender's address that was received in the message's
envelope.  For delivery failure reports, the value of this variable is
the empty string.

$sender_address_domain: The domain portion of $sender_address.

$sender_address_local_part: The local part portion of $sender_address.

$sender_fullhost: When a message is received from a remote host, this
variable contains the host name and IP address in a single string,
which always ends with the IP address in square brackets.  If
"log_incoming_port" is set, the port number on the remote host is added
to the IP address, separated by a full stop.  The format of the rest of
the string depends on whether the host issued a HELO or EHLO SMTP
command, and whether the host name was verified by looking up its IP
address.  A plain host name at the start of the string is a verified
host name; if this is not present, verification either failed or was
not requested. A host name in parentheses is the argument of a HELO or
EHLO command. This is omitted if it is identical to the verified host
name or to the host's IP address in square brackets.

$sender_helo_name: When a message is received from a remote host that
has issued a HELO or EHLO command, the first item in the argument of
that command is placed in this variable. It is also set if HELO or EHLO
is used when a message is received using SMTP locally via the -bs or -bS
options.

$sender_host_address: When a message is received from a remote host,
this variable contains that host's IP address.

$sender_host_name: When a message is received from a remote host, this
variable contains the host's name as verified by looking up its IP
address. If verification failed, or was not requested, this variable
contains the empty string.

$sender_host_port: When a message is received from a remote host, this
variable contains the port number that was used on the remote host.

$sender_ident: When a message is received from a remote host, this
variable contains the identification received in response to an RFC
1413 request. When a message has been received locally, this variable
contains the login name of the user that called Exim.

$sn0 - $sn9: These variables are copies of the values of the $n0 - $n9
accumulators that were current at the end of the system filter file.
This allows a system filter file to set values that can be tested in
users' filter files. For example, a system filter could set a value
indicating how likely it is that a message is junk mail.

$thisaddress: This variable is set only during the processing of the
"foranyaddress" command in a filter file. Its use is explained in the
description of that command.

$tod_bsdinbox: The time of day and date, in the format required for
BSD-style mailbox files, for example: Thu Oct 17 17:14:09 1995.

$tod_full: A full version of the time and date, for example: Wed, 16 Oct
1995 09:51:40 +0100. The timezone is always given as a numerical offset
from GMT.

$tod_log: The time and date in the format used for writing Exim's log
files, for example: 1995-10-12 15:32:29.

$value: This variable contains the result of an expansion lookup or
extraction operation, as described above.  If $value is used in other
circumstances, its contents are null.

$version_number: The version number of Exim.



Tag Table:
Node: Top88
Node: Exim's interface to mail filtering974
Node: Introduction2307
Node: Testing a new filter file4038
Node: Installing a filter file8368
Node: Testing an installed filter file8914
Node: Format of filter files10411
Node: String expansion13401
Node: Header variables17567
Node: User variables19340
Node: Significant deliveries20003
Node: Filter commands21263
Node: The add command22616
Node: The deliver command23231
Node: The save command25375
Node: The pipe command27467
Node: Mail commands32070
Node: Logging commands37583
Node: Other commands39851
Node: Obeying commands conditionally40924
Node: String testing conditions42285
Node: Numeric testing conditions45681
Node: Testing for personal mail46381
Node: Testing for significant deliveries49098
Node: Testing for error messages49553
Node: Testing delivery status50222
Node: Testing a list of addresses51132
Node: Multiple personal mailboxes53319
Node: Ignoring delivery errors55145
Node: Examples of filter commands55861
Node: More about string expansion57381
Node: Expansion items59096
Node: Expansion operators70351
Node: Expansion conditions78119
Node: Expansion variables85505

End Tag Table
