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diff --git a/rubbos/app/apache2/manual/howto/cgi.html.en b/rubbos/app/apache2/manual/howto/cgi.html.en deleted file mode 100644 index c3299f6c..00000000 --- a/rubbos/app/apache2/manual/howto/cgi.html.en +++ /dev/null @@ -1,555 +0,0 @@ -<?xml version="1.0" encoding="ISO-8859-1"?> -<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> -<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en"><head><!-- - XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX - This file is generated from xml source: DO NOT EDIT - XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX - --> -<title>Apache Tutorial: Dynamic Content with CGI - Apache HTTP Server</title> -<link href="../style/css/manual.css" rel="stylesheet" media="all" type="text/css" title="Main stylesheet" /> -<link href="../style/css/manual-loose-100pc.css" rel="alternate stylesheet" media="all" type="text/css" title="No Sidebar - Default font size" /> -<link href="../style/css/manual-print.css" rel="stylesheet" media="print" type="text/css" /> -<link href="../images/favicon.ico" rel="shortcut icon" /></head> -<body id="manual-page"><div id="page-header"> -<p class="menu"><a href="../mod/">Modules</a> | <a href="../mod/directives.html">Directives</a> | <a href="../faq/">FAQ</a> | <a href="../glossary.html">Glossary</a> | <a href="../sitemap.html">Sitemap</a></p> -<p class="apache">Apache HTTP Server Version 2.0</p> -<img alt="" src="../images/feather.gif" /></div> -<div class="up"><a href="./"><img title="<-" alt="<-" src="../images/left.gif" /></a></div> -<div id="path"> -<a href="http://www.apache.org/">Apache</a> > <a href="http://httpd.apache.org/">HTTP Server</a> > <a href="http://httpd.apache.org/docs/">Documentation</a> > <a href="../">Version 2.0</a> > <a href="./">How-To / Tutorials</a></div><div id="page-content"><div id="preamble"><h1>Apache Tutorial: Dynamic Content with CGI</h1> -<div class="toplang"> -<p><span>Available Languages: </span><a href="../en/howto/cgi.html" title="English"> en </a> | -<a href="../ja/howto/cgi.html" hreflang="ja" rel="alternate" title="Japanese"> ja </a> | -<a href="../ko/howto/cgi.html" hreflang="ko" rel="alternate" title="Korean"> ko </a></p> -</div> -</div> -<div id="quickview"><ul id="toc"><li><img alt="" src="../images/down.gif" /> <a href="#intro">Introduction</a></li> -<li><img alt="" src="../images/down.gif" /> <a href="#configuring">Configuring Apache to permit CGI</a></li> -<li><img alt="" src="../images/down.gif" /> <a href="#writing">Writing a CGI program</a></li> -<li><img alt="" src="../images/down.gif" /> <a href="#troubleshoot">But it's still not working!</a></li> -<li><img alt="" src="../images/down.gif" /> <a href="#behindscenes">What's going on behind the scenes?</a></li> -<li><img alt="" src="../images/down.gif" /> <a href="#libraries">CGI modules/libraries</a></li> -<li><img alt="" src="../images/down.gif" /> <a href="#moreinfo">For more information</a></li> -</ul></div> -<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> -<div class="section"> -<h2><a name="intro" id="intro">Introduction</a></h2> - - - <table class="related"><tr><th>Related Modules</th><th>Related Directives</th></tr><tr><td><ul><li><code class="module"><a href="../mod/mod_alias.html">mod_alias</a></code></li><li><code class="module"><a href="../mod/mod_cgi.html">mod_cgi</a></code></li></ul></td><td><ul><li><code class="directive"><a href="../mod/mod_mime.html#addhandler">AddHandler</a></code></li><li><code class="directive"><a href="../mod/core.html#options">Options</a></code></li><li><code class="directive"><a href="../mod/mod_alias.html#scriptalias">ScriptAlias</a></code></li></ul></td></tr></table> - - <p>The CGI (Common Gateway Interface) defines a way for a web - server to interact with external content-generating programs, - which are often referred to as CGI programs or CGI scripts. It - is the simplest, and most common, way to put dynamic content on - your web site. This document will be an introduction to setting - up CGI on your Apache web server, and getting started writing - CGI programs.</p> - </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> -<div class="section"> -<h2><a name="configuring" id="configuring">Configuring Apache to permit CGI</a></h2> - - - <p>In order to get your CGI programs to work properly, you'll - need to have Apache configured to permit CGI execution. There - are several ways to do this.</p> - - <h3><a name="scriptalias" id="scriptalias">ScriptAlias</a></h3> - - - <p>The - <code class="directive"><a href="../mod/mod_alias.html#scriptalias">ScriptAlias</a></code> - - directive tells Apache that a particular directory is set - aside for CGI programs. Apache will assume that every file in - this directory is a CGI program, and will attempt to execute - it, when that particular resource is requested by a - client.</p> - - <p>The <code class="directive"><a href="../mod/mod_alias.html#scriptalias">ScriptAlias</a></code> - directive looks like:</p> - - <div class="example"><p><code> - ScriptAlias /cgi-bin/ /usr/local/apache2/cgi-bin/ - </code></p></div> - - <p>The example shown is from your default <code>httpd.conf</code> - configuration file, if you installed Apache in the default - location. The <code class="directive"><a href="../mod/mod_alias.html#scriptalias">ScriptAlias</a></code> - directive is much like the <code class="directive"><a href="../mod/mod_alias.html#alias">Alias</a></code> directive, which defines a URL prefix that - is to mapped to a particular directory. <code class="directive">Alias</code> - and <code class="directive">ScriptAlias</code> are usually used for - directories that are outside of the <code class="directive"><a href="../mod/core.html#documentroot">DocumentRoot</a></code> directory. The difference between - <code class="directive">Alias</code> and <code class="directive">ScriptAlias</code> - is that <code class="directive">ScriptAlias</code> has the added meaning - that everything under that URL prefix will be considered a CGI - program. So, the example above tells Apache that any request for a - resource beginning with <code>/cgi-bin/</code> should be served from - the directory <code>/usr/local/apache2/cgi-bin/</code>, and should be - treated as a CGI program.</p> - - <p>For example, if the URL - <code>http://www.example.com/cgi-bin/test.pl</code> - is requested, Apache will attempt to execute the file - <code>/usr/local/apache2/cgi-bin/test.pl</code> - and return the output. Of course, the file will have to - exist, and be executable, and return output in a particular - way, or Apache will return an error message.</p> - - - <h3><a name="nonscriptalias" id="nonscriptalias">CGI outside of ScriptAlias directories</a></h3> - - - <p>CGI programs are often restricted to <code class="directive"><a href="../mod/mod_alias.html#scriptalias">ScriptAlias</a></code>'ed directories for security reasons. - In this way, administrators can tightly control who is allowed to - use CGI programs. However, if the proper security precautions are - taken, there is no reason why CGI programs cannot be run from - arbitrary directories. For example, you may wish to let users - have web content in their home directories with the - <code class="directive"><a href="../mod/mod_userdir.html#userdir">UserDir</a></code> directive. - If they want to have their own CGI programs, but don't have access to - the main <code>cgi-bin</code> directory, they will need to be able to - run CGI programs elsewhere.</p> - - <p>There are two steps to allowing CGI execution in an arbitrary - directory. First, the <code>cgi-script</code> handler must be - activated using the <code class="directive"><a href="../mod/mod_mime.html#addhandler">AddHandler</a></code> or <code class="directive"><a href="../mod/core.html#sethandler">SetHandler</a></code> directive. Second, - <code>ExecCGI</code> must be specified in the <code class="directive"><a href="../mod/core.html#options">Options</a></code> directive.</p> - - - <h3><a name="options" id="options">Explicitly using Options to permit CGI execution</a></h3> - - - <p>You could explicitly use the <code class="directive"><a href="../mod/core.html#options">Options</a></code> directive, inside your main server configuration - file, to specify that CGI execution was permitted in a particular - directory:</p> - - <div class="example"><p><code> - <Directory /usr/local/apache2/htdocs/somedir><br /> - <span class="indent"> - Options +ExecCGI<br /> - </span> - </Directory> - </code></p></div> - - <p>The above directive tells Apache to permit the execution - of CGI files. You will also need to tell the server what - files are CGI files. The following <code class="directive"><a href="../mod/mod_mime.html#addhandler">AddHandler</a></code> directive tells the server to treat all - files with the <code>cgi</code> or <code>pl</code> extension as CGI - programs:</p> - - <div class="example"><p><code> - AddHandler cgi-script .cgi .pl - </code></p></div> - - - <h3><a name="htaccess" id="htaccess">.htaccess files</a></h3> - - - <p>The <a href="htaccess.html"><code>.htaccess</code> tutorial</a> - shows how to activate CGI programs if you do not have - access to <code>httpd.conf</code>.</p> - - - <h3><a name="userdir" id="userdir">User Directories</a></h3> - - - <p>To allow CGI program execution for any file ending in - <code>.cgi</code> in users' directories, you can use the - following configuration.</p> - - <div class="example"><p><code> - <Directory /home/*/public_html><br /> - <span class="indent"> - Options +ExecCGI<br /> - AddHandler cgi-script .cgi<br /> - </span> - </Directory> - </code></p></div> - - <p>If you wish designate a <code>cgi-bin</code> subdirectory of - a user's directory where everything will be treated as a CGI - program, you can use the following.</p> - - <div class="example"><p><code> - <Directory /home/*/public_html/cgi-bin><br /> - <span class="indent"> - Options ExecCGI<br /> - SetHandler cgi-script<br /> - </span> - </Directory> - </code></p></div> - - - - </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> -<div class="section"> -<h2><a name="writing" id="writing">Writing a CGI program</a></h2> - - - <p>There are two main differences between ``regular'' - programming, and CGI programming.</p> - - <p>First, all output from your CGI program must be preceded by - a MIME-type header. This is HTTP header that tells the client - what sort of content it is receiving. Most of the time, this - will look like:</p> - - <div class="example"><p><code> - Content-type: text/html - </code></p></div> - - <p>Secondly, your output needs to be in HTML, or some other - format that a browser will be able to display. Most of the - time, this will be HTML, but occasionally you might write a CGI - program that outputs a gif image, or other non-HTML - content.</p> - - <p>Apart from those two things, writing a CGI program will look - a lot like any other program that you might write.</p> - - <h3><a name="firstcgi" id="firstcgi">Your first CGI program</a></h3> - - - <p>The following is an example CGI program that prints one - line to your browser. Type in the following, save it to a - file called <code>first.pl</code>, and put it in your - <code>cgi-bin</code> directory.</p> - - <div class="example"><p><code> - #!/usr/bin/perl<br /> - print "Content-type: text/html\n\n";<br /> - print "Hello, World."; - </code></p></div> - - <p>Even if you are not familiar with Perl, you should be able - to see what is happening here. The first line tells Apache - (or whatever shell you happen to be running under) that this - program can be executed by feeding the file to the - interpreter found at the location <code>/usr/bin/perl</code>. - The second line prints the content-type declaration we - talked about, followed by two carriage-return newline pairs. - This puts a blank line after the header, to indicate the end - of the HTTP headers, and the beginning of the body. The third - line prints the string "Hello, World.". And that's the end - of it.</p> - - <p>If you open your favorite browser and tell it to get the - address</p> - - <div class="example"><p><code> - http://www.example.com/cgi-bin/first.pl - </code></p></div> - - <p>or wherever you put your file, you will see the one line - <code>Hello, World.</code> appear in your browser window. - It's not very exciting, but once you get that working, you'll - have a good chance of getting just about anything working.</p> - - </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> -<div class="section"> -<h2><a name="troubleshoot" id="troubleshoot">But it's still not working!</a></h2> - - - <p>There are four basic things that you may see in your browser - when you try to access your CGI program from the web:</p> - - <dl> - <dt>The output of your CGI program</dt> - <dd>Great! That means everything worked fine. If the output is correct, - but the browser is not processing it correctly, make sure you have the - correct <code>Content-Type</code> set in your CGI program.</dd> - - <dt>The source code of your CGI program or a "POST Method Not - Allowed" message</dt> - <dd>That means that you have not properly configured Apache - to process your CGI program. Reread the section on - <a href="#configuring">configuring - Apache</a> and try to find what you missed.</dd> - - <dt>A message starting with "Forbidden"</dt> - <dd>That means that there is a permissions problem. Check the - <a href="#errorlogs">Apache error log</a> and the section below on - <a href="#permissions">file permissions</a>.</dd> - - <dt>A message saying "Internal Server Error"</dt> - <dd>If you check the - <a href="#errorlogs">Apache error log</a>, you will probably - find that it says "Premature end of - script headers", possibly along with an error message - generated by your CGI program. In this case, you will want to - check each of the below sections to see what might be - preventing your CGI program from emitting the proper HTTP - headers.</dd> - </dl> - - <h3><a name="permissions" id="permissions">File permissions</a></h3> - - - <p>Remember that the server does not run as you. That is, - when the server starts up, it is running with the permissions - of an unprivileged user - usually <code>nobody</code>, or - <code>www</code> - and so it will need extra permissions to - execute files that are owned by you. Usually, the way to give - a file sufficient permissions to be executed by <code>nobody</code> - is to give everyone execute permission on the file:</p> - - <div class="example"><p><code> - chmod a+x first.pl - </code></p></div> - - <p>Also, if your program reads from, or writes to, any other - files, those files will need to have the correct permissions - to permit this.</p> - - - - <h3><a name="pathinformation" id="pathinformation">Path information and environment</a></h3> - - - <p>When you run a program from your command line, you have - certain information that is passed to the shell without you - thinking about it. For example, you have a <code>PATH</code>, - which tells the shell where it can look for files that you - reference.</p> - - <p>When a program runs through the web server as a CGI program, - it may not have the same <code>PATH</code>. Any programs that you - invoke in your CGI program (like <code>sendmail</code>, for - example) will need to be specified by a full path, so that the - shell can find them when it attempts to execute your CGI - program.</p> - - <p>A common manifestation of this is the path to the script - interpreter (often <code>perl</code>) indicated in the first - line of your CGI program, which will look something like:</p> - - <div class="example"><p><code> - #!/usr/bin/perl - </code></p></div> - - <p>Make sure that this is in fact the path to the - interpreter.</p> - - <p>In addition, if your CGI program depends on other <a href="#env">environment variables</a>, you will need to - assure that those variables are passed by Apache.</p> - - - - <h3><a name="syntaxerrors" id="syntaxerrors">Program errors</a></h3> - - - <p>Most of the time when a CGI program fails, it's because of - a problem with the program itself. This is particularly true - once you get the hang of this CGI stuff, and no longer make - the above two mistakes. The first thing to do is to make - sure that your program runs from the command line before - testing it via the web server. For example, try:</p> - - <div class="example"><p><code> - cd /usr/local/apache2/cgi-bin<br /> - ./first.pl - </code></p></div> - - <p>(Do not call the <code>perl</code> interpreter. The shell - and Apache should find the interpreter using the <a href="#pathinformation">path information</a> on the first line of - the script.)</p> - - <p>The first thing you see written by your program should be - a set of HTTP headers, including the <code>Content-Type</code>, - followed by a blank line. If you see anything else, Apache will - return the <code>Premature end of script headers</code> error if - you try to run it through the server. See <a href="#writing">Writing a CGI program</a> above for more - details.</p> - - - <h3><a name="errorlogs" id="errorlogs">Error logs</a></h3> - - - <p>The error logs are your friend. Anything that goes wrong - generates message in the error log. You should always look - there first. If the place where you are hosting your web site - does not permit you access to the error log, you should - probably host your site somewhere else. Learn to read the - error logs, and you'll find that almost all of your problems - are quickly identified, and quickly solved.</p> - - - <h3><a name="suexec" id="suexec">Suexec</a></h3> - - - <p>The <a href="../suexec.html">suexec</a> support program - allows CGI programs to be run under different user permissions, - depending on which virtual host or user home directory they are - located in. Suexec has very strict permission checking, and any - failure in that checking will result in your CGI programs - failing with <code>Premature end of script headers</code>.</p> - - <p>To check if you are using suexec, run <code>apachectl - -V</code> and check for the location of <code>SUEXEC_BIN</code>. - If Apache finds an <code class="program"><a href="../programs/suexec.html">suexec</a></code> binary there on startup, - suexec will be activated.</p> - - <p>Unless you fully understand suexec, you should not be using it. - To disable suexec, simply remove (or rename) the <code class="program"><a href="../programs/suexec.html">suexec</a></code> - binary pointed to by <code>SUEXEC_BIN</code> and then restart the - server. If, after reading about <a href="../suexec.html">suexec</a>, - you still wish to use it, then run <code>suexec -V</code> to find - the location of the suexec log file, and use that log file to - find what policy you are violating.</p> - - </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> -<div class="section"> -<h2><a name="behindscenes" id="behindscenes">What's going on behind the scenes?</a></h2> - - - <p>As you become more advanced in CGI programming, it will - become useful to understand more about what's happening behind - the scenes. Specifically, how the browser and server - communicate with one another. Because although it's all very - well to write a program that prints "Hello, World.", it's not - particularly useful.</p> - - <h3><a name="env" id="env">Environment variables</a></h3> - - - <p>Environment variables are values that float around you as - you use your computer. They are useful things like your path - (where the computer searches for the actual file - implementing a command when you type it), your username, your - terminal type, and so on. For a full list of your normal, - every day environment variables, type - <code>env</code> at a command prompt.</p> - - <p>During the CGI transaction, the server and the browser - also set environment variables, so that they can communicate - with one another. These are things like the browser type - (Netscape, IE, Lynx), the server type (Apache, IIS, WebSite), - the name of the CGI program that is being run, and so on.</p> - - <p>These variables are available to the CGI programmer, and - are half of the story of the client-server communication. The - complete list of required variables is at - <a href="http://hoohoo.ncsa.uiuc.edu/cgi/env.html">http://hoohoo.ncsa.uiuc.edu/cgi/env.html</a>.</p> - - <p>This simple Perl CGI program will display all of the - environment variables that are being passed around. Two - similar programs are included in the - <code>cgi-bin</code> - - directory of the Apache distribution. Note that some - variables are required, while others are optional, so you may - see some variables listed that were not in the official list. - In addition, Apache provides many different ways for you to - <a href="../env.html">add your own environment variables</a> - to the basic ones provided by default.</p> - - <div class="example"><p><code> - #!/usr/bin/perl<br /> - print "Content-type: text/html\n\n";<br /> - foreach $key (keys %ENV) {<br /> - <span class="indent"> - print "$key --> $ENV{$key}<br>";<br /> - </span> - } - </code></p></div> - - - <h3><a name="stdin" id="stdin">STDIN and STDOUT</a></h3> - - - <p>Other communication between the server and the client - happens over standard input (<code>STDIN</code>) and standard - output (<code>STDOUT</code>). In normal everyday context, - <code>STDIN</code> means the keyboard, or a file that a - program is given to act on, and <code>STDOUT</code> - usually means the console or screen.</p> - - <p>When you <code>POST</code> a web form to a CGI program, - the data in that form is bundled up into a special format - and gets delivered to your CGI program over <code>STDIN</code>. - The program then can process that data as though it was - coming in from the keyboard, or from a file</p> - - <p>The "special format" is very simple. A field name and - its value are joined together with an equals (=) sign, and - pairs of values are joined together with an ampersand - (&). Inconvenient characters like spaces, ampersands, and - equals signs, are converted into their hex equivalent so that - they don't gum up the works. The whole data string might look - something like:</p> - - <div class="example"><p><code> - name=Rich%20Bowen&city=Lexington&state=KY&sidekick=Squirrel%20Monkey - </code></p></div> - - <p>You'll sometimes also see this type of string appended to - a URL. When that is done, the server puts that string - into the environment variable called - <code>QUERY_STRING</code>. That's called a <code>GET</code> - request. Your HTML form specifies whether a <code>GET</code> - or a <code>POST</code> is used to deliver the data, by setting the - <code>METHOD</code> attribute in the <code>FORM</code> tag.</p> - - <p>Your program is then responsible for splitting that string - up into useful information. Fortunately, there are libraries - and modules available to help you process this data, as well - as handle other of the aspects of your CGI program.</p> - - </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> -<div class="section"> -<h2><a name="libraries" id="libraries">CGI modules/libraries</a></h2> - - - <p>When you write CGI programs, you should consider using a - code library, or module, to do most of the grunt work for you. - This leads to fewer errors, and faster development.</p> - - <p>If you're writing CGI programs in Perl, modules are - available on <a href="http://www.cpan.org/">CPAN</a>. The most - popular module for this purpose is <code>CGI.pm</code>. You might - also consider <code>CGI::Lite</code>, which implements a minimal - set of functionality, which is all you need in most programs.</p> - - <p>If you're writing CGI programs in C, there are a variety of - options. One of these is the <code>CGIC</code> library, from - <a href="http://www.boutell.com/cgic/">http://www.boutell.com/cgic/</a>.</p> - </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> -<div class="section"> -<h2><a name="moreinfo" id="moreinfo">For more information</a></h2> - - - <p>There are a large number of CGI resources on the web. You - can discuss CGI problems with other users on the Usenet group - <a href="news:comp.infosystems.www.authoring.cgi">comp.infosystems.www.authoring.cgi</a>. And the -servers mailing - list from the HTML Writers Guild is a great source of answers - to your questions. You can find out more at - <a href="http://www.hwg.org/lists/hwg-servers/">http://www.hwg.org/lists/hwg-servers/</a>.</p> - - <p>And, of course, you should probably read the CGI - specification, which has all the details on the operation of - CGI programs. You can find the original version at the - <a href="http://hoohoo.ncsa.uiuc.edu/cgi/interface.html">NCSA</a> and there is an updated draft at the - <a href="http://web.golux.com/coar/cgi/">Common Gateway - Interface RFC project</a>.</p> - - <p>When you post a question about a CGI problem that you're - having, whether to a mailing list, or to a newsgroup, make sure - you provide enough information about what happened, what you - expected to happen, and how what actually happened was - different, what server you're running, what language your CGI - program was in, and, if possible, the offending code. This will - make finding your problem much simpler.</p> - - <p>Note that questions about CGI problems should <strong>never</strong> - be posted to the Apache bug database unless you are sure you - have found a problem in the Apache source code.</p> - </div></div> -<div class="bottomlang"> -<p><span>Available Languages: </span><a href="../en/howto/cgi.html" title="English"> en </a> | -<a href="../ja/howto/cgi.html" hreflang="ja" rel="alternate" title="Japanese"> ja </a> | -<a href="../ko/howto/cgi.html" hreflang="ko" rel="alternate" title="Korean"> ko </a></p> -</div><div id="footer"> -<p class="apache">Copyright 2009 The Apache Software Foundation.<br />Licensed under the <a href="http://www.apache.org/licenses/LICENSE-2.0">Apache License, Version 2.0</a>.</p> -<p class="menu"><a href="../mod/">Modules</a> | <a href="../mod/directives.html">Directives</a> | <a href="../faq/">FAQ</a> | <a href="../glossary.html">Glossary</a> | <a href="../sitemap.html">Sitemap</a></p></div> -</body></html>
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