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 FastC-
GI
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 do-
main
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 speci-
fies
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 listen-
ing 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-fc-
gi.
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 Do-
main
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 lis-
tening
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 1.1.1.1 1997/09/16 15:36:26 stanleyg Exp $