From: Alexei Kosut Date: Fri, 20 Dec 1996 05:42:13 +0000 (+0000) Subject: Document the change in SCRIPT_NAME/PATH_INFO behavior, and the addition of X-Git-Tag: APACHE_1_2b3~16 X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=5d5ff2d5981058898f1216587f0e2ecfff286d84;p=apache Document the change in SCRIPT_NAME/PATH_INFO behavior, and the addition of FILEPATH_INFO. git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@77293 13f79535-47bb-0310-9956-ffa450edef68 --- diff --git a/docs/manual/cgi_path.html b/docs/manual/cgi_path.html new file mode 100644 index 0000000000..81bb314ead --- /dev/null +++ b/docs/manual/cgi_path.html @@ -0,0 +1,84 @@ + +PATH_INFO Changes in the CGI Environment + + + +

PATH_INFO Changes in the CGI Environment

+ +

Overview

+ +

As implemented in Apache 1.1.1 and earlier versions, the method +Apache used to create PATH_INFO in the CGI environment was +counterintiutive, and could result in crashes in certain cases. In +Apache 1.2 and beyond, this behavior has changed. Although this +results in some compatibility problems with certain legacy CGI +applications, the Apache 1.2 behavior is still compatible with the +CGI/1.1 specification, and CGI scripts can be easily modified (see below). + +

The Problem

+ +

Apache 1.1.1 and earlier implemented the PATH_INFO and SCRIPT_NAME +environment variables by looking at the filename, not the URL. While +this resulted in the correct values in many cases, when the filesystem +path was overloaded to contain path information, it could result in +errant behavior. For example, if the following appeared in a config +file: +

+     Alias /cgi-ralph /usr/local/httpd/cgi-bin/user.cgi/ralph
+

In this case, user.cgi is the CGI script, the "/ralph" +is information to be passed onto the CGI. If this configuration was in +place, and a request came for "/cgi-ralph/script/", the +code would set PATH_INFO to "/ralph/script", and +SCRIPT_NAME to "/cgi-". Obviously, the latter is +incorrect. In certain cases, this could even cause the server to +crash.

+ +

The Solution

+ +

Apache 1.2 and later now determine SCRIPT_NAME and PATH_INFO by +looking directly at the URL, and determining how much of the URL is +client-modifiable, and setting PATH_INFO to it. To use the above +example, PATH_INFO would be set to "/script", and +SCRIPT_NAME to "/cgi-ralph". This makes sense and results +in no server behavior problems. It also permits the script to be +gauranteed that +"http://$SERVER_NAME:$SERVER_PORT$SCRIPT_NAME$PATH_INFO" +will always be an accessable URL that points to the current script, +something which was not neccessarily true with previous versions of +Apache. + +

However, the "/ralph" +information from the Alias directive is lost. This is +unfortunate, but we feel that using the filesystem to pass along this +sort of information is not a recommended method, and a script making +use of it "deserves" not to work. Apache 1.2b3 and later, however, do +provide a workaround. + +

Compatibility with Previous Servers

+ +

It may be neccessary for a script that was designed for earlier +versions of Apache or other servers to need the information that the +old PATH_INFO variable provided. For this purpose, Apache 1.2 (1.2b3 +and later) sets an additional variable, FILEPATH_INFO. This +environment variable contains the value that PATH_INFO would have had +with Apache 1.1.1.

+ +

A script that wishes to work with both Apache 1.2 and earlier +versions can simply test for the existance of FILEPATH_INFO, and use +it if available. Otherwise, it can use PATH_INFO. For example, in +Perl, one might use: +

+    $path_info = $ENV{'FILEPATH_INFO'} || $ENV{'PATH_INFO'};
+

+ +

By doing this, a script can work with all servers supporting the +CGI/1.1 specification, including all versions of Apache.

+ + + + + diff --git a/docs/manual/cgi_path.html.en b/docs/manual/cgi_path.html.en new file mode 100644 index 0000000000..81bb314ead --- /dev/null +++ b/docs/manual/cgi_path.html.en @@ -0,0 +1,84 @@ + +PATH_INFO Changes in the CGI Environment + + + +