From 136f42f503cb3e9588e62332d043e92b7475ec4e Mon Sep 17 00:00:00 2001 From: Denis Vlasenko Date: Sun, 11 Feb 2007 14:52:07 +0000 Subject: Add CGI docs --- docs/cgi/out.html | 126 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 126 insertions(+) create mode 100644 docs/cgi/out.html (limited to 'docs/cgi/out.html') 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 @@ +CGI Script output

CGI Script Output

+ +

Script output

+ +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.

+ +

Script naming conventions

+ +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.

+ +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.

+ +

Parsed headers

+ +The output of scripts begins with a small header. This header consists +of text lines, in the same format as an +HTTP header, terminated by a blank line (a line with only a +linefeed or CR/LF).

+ +Any headers which are not server directives are sent directly back to +the client. Currently, this specification defines three server +directives:

+ +

Content-type
+ + This is the MIME type of the document you are returning.
+ +
Location
+ + This is used to specify to the server that you are returning a + reference to a document rather than an actual document.
+ + If the argument to this is a URL, the server will issue a redirect + to the client.
+ + 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.
+ + +
Status
+ + This is used to give the server an HTTP/1.0 status +line to send to the client. The format is nnn xxxxx, +where nnn is the 3-digit status code, and +xxxxx is the reason string, such as "Forbidden".
+ +

+ +

Examples

+ +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):

+ +

--- start of output ---
+Content-type: text/html
+
+--- end of output ---
+

+ +Note the blank line after Content-type.

+ +Now, let's say I have a script which, in certain instances, wants to +return the document /path/doc.txt from this server just +as if the user had actually requested +http://server:port/path/doc.txt to begin with. In this +case, the script would output:

--- start of output ---
+Location: /path/doc.txt
+
+--- end of output ---
+

+ +The server would then perform the request and send it to the client. +

+ +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 +gopher://gopher.ncsa.uiuc.edu/, it would output:

+ +

--- start of output ---
+Location: gopher://gopher.ncsa.uiuc.edu/
+
+--- end of output ---
+

+ +Finally, I have a script which wants to talk to the client directly. +In this case, if the script is referenced with SERVER_PROTOCOL of HTTP/1.0, +the script would output the following HTTP/1.0 response:

+ +

--- 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 ---
+

+ + +

+ +

Return to the +interface specification

+ +CGI - Common Gateway Interface +

cgi@ncsa.uiuc.edu

+ \ No newline at end of file -- cgit v1.1