NAME
cgi-fcgi - bridge from CGI to FastCGI

SYNOPSIS
cgi-fcgi -f cmdPath
cgi-fcgi -bind -connect connName
cgi-fcgi -start -connect connName appPath [nServers]
cgi-fcgi -connect connName appPath [nServers]

DESCRIPTION
cgi-fcgi is a CGI/1.1 program that communicates with an
already-running FastCGI application in order to respond to an
HTTP request. cgi-fcgi is also capable of starting a FastCGI
application.

When you invoke cgi-fcgi as

cgi-fcgi -f cmdPath

then cgi-fcgi opens the file at cmdPath and reads its
arguments from that file. cgi-fcgi will skip lines
that begin with the comment character #. The first
non-comment line should contain valid arguments in
one of the other three forms.

The -f form of cgi-fcgi is designed for Unix systems
whose exec(2) family of system calls supports the execution of
command interpreter files. For instance, if a file with
execute permission contains the text

#! /bin/cgi-fcgi -f
-connect /httpd/root/sock/app /httpd/root/bin/app

the effect is the same as executing

/bin/cgi-fcgi -connect /httpd/root/sock/app /httpd/root/bin/app

When you invoke cgi-fcgi as

cgi-fcgi -bind -connect connName

the connName argument is either the path name of a Unix domain
listening socket or a host:port pair. If connName contains
a colon, it is assumed to be host:port. cgi-fcgi performs
a connect(2) using connName. If the connect succeeds, cgi-fcgi
forwards the CGI environment variables and stdin data to the
FastCGI application, and forwards the stdout and stderr data from
the application to cgi-fcgi's stdout (most likely connected to
a Web server). When the FastCGI application signals the end of
its response, cgi-fcgi flushes its buffers and
exits, and the Web server completes the http response.

When you invoke cgi-fcgi as

cgi-fcgi -start -connect connName appPath [nServers]

then cgi-fcgi performs the function of starting one or more
FastCGI application processes. The connName argument specifies
either the path name of the Unix domain listening socket that
cgi-fcgi will create, or is "localhost:NNN" where NNN is the port
number of the TCP/IP listening socket that cgi-fcgi will create
on the local machine. (cgi-fcgi will not create processes
on remote machines.) After cgi-fcgi creates the listening socket,
it forks nServers copies of a process running the executable file
appPath. If nServers is omitted, the effect is as if the value "1"
had been specified. The processes share the single listening socket.

When you invoke cgi-fcgi as

cgi-fcgi -connect connName appPath [nServers]

cgi-fcgi performs -bind and then, if necssary, performs -start
and repeats the -bind. That is, cgi-fcgi first operates as if
the command had been

cgi-fcgi -bind -connect connName

If the connect fails, cgi-fcgi tries

cgi-fcgi -start -connect connName appPath [nServers]

and finally retries

cgi-fcgi -bind -connect connName

In this form, cgi-fcgi does not support TCP/IP connections.

ENVIRONMENT VARIABLES
The usual CGI ones, but they are not interpreted by cgi-fcgi.

SEE ALSO
FGCI_accept(3)

BUGS
cgi-fcgi doesn't generate useful HTTP responses in case of error,
and it generates no response at all when run as start-fcgi.

On Digital UNIX 3.0 systems the implementation of Unix Domain
sockets does not work when such sockets are stored on NFS file
systems. Symptom: cgi-fcgi may core dump or may exit with
status 38. Work-around: store sockets in local file systems
(/tmp often works) or use TCP/IP.

On AIX systems the implementation of listening sockets
does not support socket sharing, and the standard FastCGI
application libraries can't synchronize access to AIX listening
sockets. Work-around: Don't use the nServers argument on AIX.

HISTORY
Copyright (c) 1996 Open Market, Inc.
See the file "LICENSE.TERMS" for information on usage and redistribution
of this file, and for a DISCLAIMER OF ALL WARRANTIES.
$Id: cgi-fcgi.1,v 1.1 1997/09/16 15:36:26 stanleyg Exp $