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
- /usr/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).
(in Debian, /usr/share/doc/libfcgi?/*)
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 1.1.1.1 1997/09/16 15:36:26 stanleyg Exp
$