# Overview of the Apache TPF Port

[ Configuration Files | What's Available | CGI Scripts | Porting Notes ]

This version of Apache includes changes allowing it to run on IBM's EBCDIC-based TPF (Transaction Processing Facility) operating system. Unless otherwise noted TPF version 4.1 PUT09 is required.
Refer to htdocs/manual/install-tpf.html for step-by-step installation instructions.
As this is the first cut at making Apache run on TPF, performance tuning has not been done.
This port builds upon the EBCDIC changes previously made to Apache.

## Apache Configuration Files

The distributed configuration files (httpd.conf-dist and mime.types, both located in the conf subdirectory) work on TPF. Performance considerations may dictate setting KeepAlive to "Off" (the default is "On") or lowering the Timeout value from the default 300 seconds (5 minutes) in order to reduce the number of active ECBs on your system.

## What's Available in this Version

(The Apache organization provides online documentation describing the various modules and components of the server.)

### Components/modules tested on TPF:

- alloc.c
- ap_base64.c
- ap_checkpass.c
- ap_cpystrn.c
- ap_fnmatch.c
- ap_md5c.c
- ap_sha1.c
- ap_signal.c
- ap_slack.c
- ap_snprintf.c
- buff.c
- buildmark.c
- ebcdic.c
- gen_test.char.c
- gen_uri_delims.c
- htpasswd.c (requires PUT10)
- http_config.c
- http_core.c
- http_log.c
- http_main.c
- http_protocol.c
- http_request.c
- http_vhost.c
- logresolve.c (requires PUT10)
- mod_access.c (see note 1)
- mod_actions.c
- mod_alias.c
- mod_asis.c
- mod_auth.c
- mod_auth_anon.c
- mod_autoindex.c
- mod_cern_meta.c
- mod_cgi.c (requires PUT10)
- mod_digest.c
- mod_dir.c
- mod_env.c
- mod_example.c
- mod_expires.c
- mod_headers.c
- mod_imap.c
- mod_include.c (see note 2)
- mod_info.c
- mod_log_agent.c
- mod_log_config.c
- mod_log_referer.c
- mod_mime.c
- mod_mime_magic.c
- mod_negotiation.c
- mod_put.c (third party module)
- mod_proxy.c
- mod_setenvif.c
- mod_speling.c
- mod_status.c
- mod_tpf_shm_static.c (third party module, requires PUT10)
- mod_unique_id.c (requires PUT10)
- mod_userdir.c
- mod_usertrack.c
- os.c
- os-inline.c
- proxy_cache.c
- proxy_connect.c
- proxy_ftp.c
- proxy_http.c
- proxy_util.c
- regular expression parser
- regular expression test tool (requires PUT10)
- rfc1413.c
- rotatelogs.c (requires PUT10)
- util.c
- util_date.c
- util_md5.c
- util_script.c
- util_uri.c

Notes:

1. Use of mod_access directives "`allow from`" & "`deny from`" with host names (verses ip addresses) requires TPF version 4.1 PUT10
2. CGI execution requires TPF version 4.1 PUT10

### Components/modules not yet supported on TPF:

- htdigest.c
- lib/expat-lite
- mod_auth_digest.c
- mod_rewrite.c
- mod_vhost_alias.c

### Components/modules that don't apply or that probably won't ever be available on TPF:

- ab.c
- ap_getpass.c
- mod_auth_db.c
- mod_auth_dbm.c
- mod_auth_db.module
- mod_mmap_static.c
- mod_so.c
- suexec.c

## How to Use CGI Scripts

The following is a very simple example of a CGI script ("Hello World") and the necessary steps to run it.
Refer to the mod_cgi module for additional information.

### Add necessary directives to httpd.conf:

Example: `

ScriptLog logs/script_log
ScriptAlias /cgi-bin/ /usr/local/apache/cgi-bin/

`

A request for `http://myserver/cgi-bin/filename.cgi` would cause the server to run the script `/usr/local/apache/cgi-bin/filename.cgi`

### Create the CGI script:

For this example `QZZ1` is the name of the TPF program that will be executed by the CGI script.
The directory path must match what is in the httpd.conf file for `ScriptAlias` directive.

`zfile echo "#!QZZ1" > /usr/local/apache/cgi-bin/filename.cgi
zfile cat /usr/local/apache/cgi-bin/filename.cgi` (this should display`#!QZZ1`)

### Mark the script as executable:

`zfile chmod 755 /usr/local/apache/cgi-bin/filename.cgi
`

### Create, load, and activate a loadset containing the CGI program (QZZ1xx):

`/** QZZ1-- simple "Hello world" program to demonstrate basic CGI output **/
#include <stdio.h>
void main() {

/** Print the CGI response header, required for all HTML output. **/
/** Note the extra \n, to send the blank line. **/
printf("Content-type: text/html\n\n");
/** Print the HTML response page to stdout. **/
printf("<html>\n");
printf("<head><title> CGI Output </title></head>\n");
printf("<body>\n");
printf("<h1> Hello world </h1> \n");
printf("</body>\n");
printf("</html>\n");

}
`

### Request the CGI script from a browser:

`http://myserver/cgi-bin/filename.cgi`

## Porting Notes

### Changes made due to differences between UNIX and TPF's process models:

- Signals: On TPF a signal that is sent to a process remains unhandled until the process explicitly requests that signals be handled using the `tpf_process_signals()` function. Additionally, the default action for an alarm on TPF is to take an OPR-7777 dump and exit. (On UNIX the default is the equivalent of `exit()` with no dump taken.) These differences necessitated a few modifications:
  - bypass the use of `ap_block_alarms()` & `ap_unblock_alarms()`
  - add `tpf_process_signals()` calls
  - add `select()` calls to prevent blocking.

### Find that function...

Some simple functions & definitions initially needed to be added on TPF, such as `FD_SET()`. We've put these in src/os/tpf/os.h for now.

### EBCDIC changes:

TPF-specific conversion tables between US-ASCII and EBCDIC (character set IBM-1047 to be exact) were created and put into ebcdic.c in the src/os/tpf directory.

### Miscellaneous, minor changes:

Various minor changes (such as casting) were made due to differences in how some functions are implemented on TPF.

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