Apache includes changes allowing it to run on IBM's EBCDIC-based TPF (Transaction Processing Facility) operating system. This builds on the EBCDIC changes previously made to Apache.

Refer to either the TPF4.1 installation or z/TPF1.1 installation documents for step-by-step build instructions.

If you would like to be notified when new versions of Apache are released consider joining the announcements list.

The distributed configuration files (httpd.conf-dist and mime.types, both located in the conf subdirectory) work on TPF with the following caveats:

• Apache on TPF does not support listening on multiple ports.
• 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.
• The default value of MaxRequestsPerChild is zero (infinity). A non-zero value is recommended on TPF to control resource utilization (such as heap storage) by the long running Apache child ECBs.
• Unlike on Unix systems, newly created Apache child processes on TPF re-read the various configuration files (such as httpd.conf and mime.types). Be sure to stop and restart Apache after changing configuration files so that the Apache parent process and all child processes are in sync.

Unless otherwise noted either TPF4.1 PUT09 or z/TPF1.1 is required for the server to function on TPF.

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_ebcdic.c
• ap_fnmatch.c
• ap_md5c.c
• ap_sha1.c
• ap_signal.c
• ap_slack.c
• ap_snprintf.c
• buff.c
• buildmark.c
• http_config.c
• http_core.c
• http_log.c
• http_main.c
• http_protocol.c
• http_request.c
• http_vhost.c
• logresolve.c (requires TPF4.1 PUT 10 or z/TPF1.1)
• mod_access.c (Use of mod_access directives "allow from" & "deny from" with host names (versus ip addresses) requires TPF4.1 PUT 10 or z/TPF1.1)
• 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 TPF4.1 PUT 10 or z/TPF1.1)
• mod_digest.c
• mod_dir.c
• mod_env.c
• mod_example.c
• mod_expires.c
• mod_headers.c
• mod_imap.c
• mod_include.c (CGI execution requires TPF4.1 PUT 10 or z/TPF1.1)
• mod_info.c
• mod_log_agent.c
• mod_log_config.c
• mod_log_forensic.c
• mod_log_referer.c
• mod_mime.c
• mod_mime_magic.c
• mod_negotiation.c
• mod_put.c (third party module)
• mod_setenvif.c
• mod_speling.c
• mod_status.c
• mod_tpf_shm_static.c (third party module, requires TPF4.1 PUT 10 or z/TPF1.1)
• mod_unique_id.c (requires TPF4.1 PUT 10 or z/TPF1.1)
• mod_userdir.c
• mod_usertrack.c
• os.c
• os-inline.c
• regular expression parser (used only on TPF4.1)
• regular expression test tool (used only on TPF4.1; requires TPF4.1 PUT 10 )
• rfc1413.c
• rotatelogs.c (requires TPF4.1 PUT 10 or z/TPF1.1; on TPF4.1, if PJ27214 is implemented be sure to apply PJ28367)
• syslog (requires TPF4.1 PUT13 or z/TPF1.1; see usage instructions)
• util.c
• util_date.c
• util_md5.c
• util_script.c
• util_uri.c

Components/modules not yet supported on TPF:

• htdigest.c
• htpasswd.c
• lib/expat-lite
• lib/sdbm
• mod_auth_digest.c
• mod_proxy.c
• mod_rewrite.c
• mod_vhost_alias.c
• proxy_cache.c
• proxy_connect.c
• proxy_ftp.c
• proxy_http.c
• proxy_util.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

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     (expected output: #!QZZ1)

Mark the script as executable:

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

Create, load, and activate the CGI program (QZZ1) on TPF:

/* QZZ1-- simple "Hello world" program to demonstrate basic CGI output */

#include <stdio.h>
#include <stdlib.h>

int main() {

   /* Print the CGI response header, required for all HTML output. */
   /* Note the extra \n, to send the blank line.                   */
   /* Print the HTML response page to STDOUT.                      */
   printf("Content-type: text/html\n\n");

   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");

   exit(0);
}
                

Request the CGI script from a browser:

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

Overview of Apache's "dash" options:

Apache can be invoked with various options, such as "-f". Some of these options display information about the server or perform syntax checks but they don't actually start the server. These "information only" options are useful with TPF's ZFILE command line feature: -h, -l, -L, -S, -t, -T, -v, and -V.

Another option, -X, is used when actually running the server. It is passed to Apache through the ZINET XPARM field since ZINET is the only way to start the server on TPF.

A third group of options apply to both the informational displays (ZFILE) and running the server (ZINET XPARM): -d, -D and -f.

The rest of Apache's options are either not applicable or are not supported on TPF.

On TPF4.1 using dash options requires PJ27277 which shipped on PUT13.

Table of supported Apache options

See http://httpd.apache.org/docs/programs/httpd.html for more information about these command line options.

Setup for ZFILE examples:

Ensure Apache (CHTA) is loaded.

Create the httpd script:

zfile echo "#!CHTA" > /bin/httpd
zfile cat /bin/httpd   (expected output:  #!CHTA)

(See "ZFILE-Activate a TPF Segment or Script" in the IBM TPF Information Center for additional information.)

Mark the script as executable:

zfile chmod 755 /bin/httpd

ZFILE example 1:

zfile httpd -v

FILE0001I 11.43.09 START OF DISPLAY FROM httpd -v          
Server version: Apache/1.3.20 (TPF)
Server built: May 23 2001 09:39:22
END OF DISPLAY
                

ZFILE example 2:

zfile httpd -t -f /usr/local/apache/conf/alt.conf

FILE0002I 11.47.26 START OF ERROR DISPLAY FROM httpd -t ...
Syntax OK
END OF DISPLAY
                

ZINET XPARM example:

This example uses an alternate configuration file called /usr/local/apache/conf/alt.conf.

Create and transfer your alternate configuration file to your TPF test system.

Add and start Apache using zinet commands:

zinet add s-apache pgm-chta model-daemon user-root xparm--f conf/alt.conf
zinet start s-apache

(See "ZINET ADD-Add an Internet Server Application Entry" and "ZINET ALTER-Change an Internet Server Application Entry" in the IBM TPF Information Center for more information about using the XPARM field.)

Syslog overview:

The syslog daemon is a server process that provides a message logging facility for application and system processes. It can be used to write messages to log files or to tapes. See "Operating the Syslog Daemon" in the IBM TPF Information Center. And see the Apache ErrorLog directive documentation for details on how to use syslog with Apache.

On TPF4.1 syslog capabilities were added with PJ27214 which shipped with PUT13. You must follow the TPF4.1 syslog-specific installation instructions in order to have the option of using syslog with Apache on a TPF4.1 system. No additional installation steps are needed for z/TPF1.1 systems.

Tips on using syslog with your Apache error log:

This section provides some tips on using syslog with Apache. It is not meant to replace the syslog documentation in the TPF TCP/IP publication.

• The syslog daemon will not create files. If you are logging to a file (as specified in the syslog.conf configuration file) that file must already exist and have permissions that allow the syslog daemon to write to it.
• You must restart the syslog daemon for it to recognize changes to its syslog.conf configuration file.
• The syslog daemon must be active prior to starting Apache.
• To indicate you want to use syslog with your Apache error log add the following directive to your httpd.conf file: "ErrorLog syslog:facility" where facility is "local0" through "local7".
• Apache will default the facility to "local7" if you omit the facility name from the ErrorLog directive (that is "ErrorLog syslog").
• The syslog facility name must be one that is recognized by both Apache and the syslog.h header file. The facility names "local0" through "local7" are explicitly set aside for your use.
• Although "local0" through "local7" are recommended user facility names, here is the complete list of names recognized by both Apache and TPF's syslog.h: auth, cron, daemon, kern, local0, local1, local2, local3, local4, local5, local6, local7, lpr, mail, news, syslog, user, and uucp.
• You won't see the normal Apache startup/shutdown messages when you use syslog with your Apache error log.
• Syslog does not support TCP/IP Offload devices (ZCLAW; used only on TPF4.1)

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 needed to be added on TPF. They are in src/os/tpf/os.h.

• EBCDIC changes: TPF-specific conversion tables between US-ASCII and EBCDIC (character set IBM-1047 to be exact) were created.

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