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| author | Denis Vlasenko | 2007-02-11 14:52:07 +0000 |
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| committer | Denis Vlasenko | 2007-02-11 14:52:07 +0000 |
| commit | 136f42f503cb3e9588e62332d043e92b7475ec4e (patch) | |
| tree | 81c556d1a136112be07bbd2c19293e65fad03cdd /docs/cgi/out.html | |
| parent | ad67a3925c78e7c9f8e61248f640c5cc7a5cf186 (diff) | |
| download | busybox-136f42f503cb3e9588e62332d043e92b7475ec4e.zip busybox-136f42f503cb3e9588e62332d043e92b7475ec4e.tar.gz | |
Add CGI docs
Diffstat (limited to 'docs/cgi/out.html')
| -rw-r--r-- | docs/cgi/out.html | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/docs/cgi/out.html b/docs/cgi/out.html new file mode 100644 index 0000000..2203ee5 --- /dev/null +++ b/docs/cgi/out.html @@ -0,0 +1,126 @@ +<html><head><title>CGI Script output</title></head><body><h1><img alt="" src="out_files/CGIlogo.gif"> CGI Script Output</h1> +<hr> + +<h2>Script output</h2> + +The script sends its output to stdout. This output can either be a +document generated by the script, or instructions to the server for +retrieving the desired output. <p> +</p><hr> + +<h2>Script naming conventions</h2> + +Normally, scripts produce output which is interpreted and sent back to +the client. An advantage of this is that the scripts do not need to +send a full HTTP/1.0 header for every request. <p> +<a name="nph"> +Some scripts may want to avoid the extra overhead of the server +parsing their output, and talk directly to the client. In order to +distinguish these scripts from the other scripts, CGI requires that +the script name begins with nph- if a script does not want the server +to parse its header. In this case, it is the script's responsibility +to return a valid HTTP/1.0 (or HTTP/0.9) response to the client. </a></p><p> + +</p><hr> +<h2><a name="nph">Parsed headers</a></h2> + +<a name="nph">The output of scripts begins with a small header. This header consists +of text lines, in the same format as an </a><a href="http://www.w3.org/hypertext/WWW/Protocols/HTTP/Object_Headers.html"> +HTTP header</a>, terminated by a blank line (a line with only a +linefeed or CR/LF). <p> + +Any headers which are not server directives are sent directly back to +the client. Currently, this specification defines three server +directives:</p><p> + +</p><ul> +<li> <code>Content-type</code> <p> + + This is the MIME type of the document you are returning. </p><p> + +</p></li><li> <code>Location</code> <p> + + This is used to specify to the server that you are returning a + reference to a document rather than an actual document. </p><p> + + If the argument to this is a URL, the server will issue a redirect + to the client. </p><p> + + If the argument to this is a virtual path, the server will + retrieve the document specified as if the client had requested + that document originally. ? directives will work in here, but # + directives must be redirected back to the client.</p><p> + + +</p></li><li> <a name="status"><code>Status</code></a><p> + + This is used to give the server an HTTP/1.0 <a href="http://www.w3.org/hypertext/WWW/Protocols/HTTP/HTRESP.html">status +line</a> to send to the client. The format is <code>nnn xxxxx</code>, +where <code>nnn</code> is the 3-digit status code, and +<code>xxxxx</code> is the reason string, such as "Forbidden".</p><p> + +</p></li></ul> + +<hr> +<h2>Examples</h2> + +Let's say I have a fromgratz to HTML converter. When my converter is +finished with its work, it will output the following on stdout (note +that the lines beginning and ending with --- are just for illustration +and would not be output): <p> + +</p><pre>--- start of output --- +Content-type: text/html + +--- end of output --- +</pre> + +Note the blank line after Content-type. <p> + +Now, let's say I have a script which, in certain instances, wants to +return the document <code>/path/doc.txt</code> from this server just +as if the user had actually requested +<code>http://server:port/path/doc.txt</code> to begin with. In this +case, the script would output: </p><p> +</p><pre>--- start of output --- +Location: /path/doc.txt + +--- end of output --- +</pre> + +The server would then perform the request and send it to the client. +<p> + +Let's say that I have a script which wants to reference our gopher +server. In this case, if the script wanted to refer the user to +<code>gopher://gopher.ncsa.uiuc.edu/</code>, it would output: </p><p> + +</p><pre>--- start of output --- +Location: gopher://gopher.ncsa.uiuc.edu/ + +--- end of output --- +</pre> + +Finally, I have a script which wants to talk to the client directly. +In this case, if the script is referenced with <a href="http://hoohoo.ncsa.uiuc.edu/cgi/env.html#protocol"><code>SERVER_PROTOCOL</code></a> of HTTP/1.0, +the script would output the following HTTP/1.0 response: <p> + +</p><pre>--- start of output --- +HTTP/1.0 200 OK +Server: NCSA/1.0a6 +Content-type: text/plain + +This is a plaintext document generated on the fly just for you. + +--- end of output --- +</pre> + + +<hr> + +<a href="http://hoohoo.ncsa.uiuc.edu/cgi/interface.html"><img alt="[Back]" src="out_files/back.gif">Return to the +interface specification</a> <p> + +CGI - Common Gateway Interface +</p><address><a href="http://hoohoo.ncsa.uiuc.edu/cgi/mailtocgi.html">cgi@ncsa.uiuc.edu</a></address> +</body></html>
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