CGI Command line options CGI Command line options+ +
QUERY_STRING environment variable) for a non-encoded
+= character to determine if the command line is to be used, if it
+finds one, the command line is not to be used. This trusts the clients
+to encode the = sign in ISINDEX queries, a practice which was
+considered safe at the time of the design of this specification.
+
+For example, use the finger script and the ISINDEX interface to look up "httpd". You will see that the script will call itself with /cgi-bin/finger?httpd and will actually execute "finger httpd" on the command line and output the results to you.
+
+If the server does find a "=" in the QUERY_STRING,
+then the command line will not be used, and no decoding will be
+performed. The query then remains intact for processing by an
+appropriate FORM submission decoder.
+Again, as an example, use this hyperlink to submit "httpd=name" to the finger script. Since this QUERY_STRING
+contained an unencoded "=", nothing was decoded, the script didn't know
+it was being submitted a valid query, and just gave you the default
+finger form.
+
+If the server finds that it cannot send the string due to internal
+limitations (such as exec() or /bin/sh command line restrictions) the
+server should include NO command line information and provide the
+non-decoded query information in the environment
+variable QUERY_STRING.
+
+ +
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+interface specification + +CGI - Common Gateway Interface +
cgi@ncsa.uiuc.edu + + + \ No newline at end of file diff --git a/docs/cgi/env.html b/docs/cgi/env.html new file mode 100644 index 0000000..961671a --- /dev/null +++ b/docs/cgi/env.html @@ -0,0 +1,149 @@ +
CGI Environment Variables+ +In order to pass data about the information request from the server to +the script, the server uses command line arguments as well as +environment variables. These environment variables are set when the +server executes the gateway program.
+ +
+The following environment variables are not request-specific and are +set for all requests:
+ +
SERVER_SOFTWARE + + The name and version of the information server software answering + the request (and running the gateway). Format: name/version
+ +
SERVER_NAME + The server's hostname, DNS alias, or IP address as it would appear + in self-referencing URLs.
+ +
GATEWAY_INTERFACE + The revision of the CGI specification to which this server + complies. Format: CGI/revision
+ +
+ +
SERVER_PROTOCOL + The name and revision of the information protcol this request came + in with. Format: protocol/revision
+ +
SERVER_PORT + The port number to which the request was sent.
+ +
REQUEST_METHOD + The method with which the request was made. For HTTP, this is + "GET", "HEAD", "POST", etc.
+ +
PATH_INFO + The extra path information, as given by the client. In other + words, scripts can be accessed by their virtual pathname, followed + by extra information at the end of this path. The extra + information is sent as PATH_INFO. This information should be + decoded by the server if it comes from a URL before it is passed + to the CGI script.
+ +
PATH_TRANSLATED + The server provides a translated version of PATH_INFO, which takes + the path and does any virtual-to-physical mapping to it.
+ +
SCRIPT_NAME + A virtual path to the script being executed, used for + self-referencing URLs.
+ +
QUERY_STRING + The information which follows the ? in the URL + which referenced this script. This is the query information. It + should not be decoded in any fashion. This variable should always + be set when there is query information, regardless of command line decoding.
+ +
REMOTE_HOST + The hostname making the request. If the server does not have this + information, it should set REMOTE_ADDR and leave this unset.
+ +
REMOTE_ADDR + The IP address of the remote host making the request.
+ +
AUTH_TYPE + If the server supports user authentication, and the script is + protects, this is the protocol-specific authentication method used + to validate the user.
+ +
REMOTE_USER + If the server supports user authentication, and the script is + protected, this is the username they have authenticated as.
+
REMOTE_IDENT + If the HTTP server supports RFC 931 identification, then this + variable will be set to the remote user name retrieved from the + server. Usage of this variable should be limited to logging only. +
+ +
CONTENT_TYPE + For queries which have attached information, such as HTTP POST and + PUT, this is the content type of the data.
+ +
CONTENT_LENGTH + The length of the said content as given by the client.
+ +
+ +An example of this is the HTTP_ACCEPT variable which was defined in +CGI/1.0. Another example is the header User-Agent.
+ +
HTTP_ACCEPT + The MIME types which the client will accept, as given by HTTP + headers. Other protocols may need to get this information from + elsewhere. Each item in this list should be separated by commas as + per the HTTP spec.
+ + Format: type/subtype, type/subtype
+ + +
HTTP_USER_AGENT
+
+ The browser the client is using to send the request. General
+format: software/version library/version.
+ +
+ +
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+interface specification + +CGI - Common Gateway Interface +
cgi@ncsa.uiuc.edu + + \ No newline at end of file diff --git a/docs/cgi/in.html b/docs/cgi/in.html new file mode 100644 index 0000000..679306a --- /dev/null +++ b/docs/cgi/in.html @@ -0,0 +1,33 @@ +
CGI Script Input
+
+The server will send CONTENT_LENGTH bytes on
+this file descriptor. Remember that it will give the CONTENT_TYPE of the data as well. The server is
+in no way obligated to send end-of-file after the script reads
+CONTENT_LENGTH bytes.
+
a=b&b=c.
++ +In this case, the server will set CONTENT_LENGTH to 7 and CONTENT_TYPE +to application/x-www-form-urlencoded. The first byte on the script's +standard input will be "a", followed by the rest of the encoded string.
+ +
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+interface specification + +CGI - Common Gateway Interface +
cgi@ncsa.uiuc.edu + + \ No newline at end of file diff --git a/docs/cgi/interface.html b/docs/cgi/interface.html new file mode 100644 index 0000000..33f0288 --- /dev/null +++ b/docs/cgi/interface.html @@ -0,0 +1,29 @@ +
The CGI Specification+ +The server and the CGI script communicate in four major ways. Each of +the following is a hotlink to graphic detail.
+ +
+![[Back]](interface_files/back.gif)
Return to the overview + + + +CGI - Common Gateway Interface +
cgi@ncsa.uiuc.edu + \ No newline at end of file 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+
+ +
+ +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".
+ +
+ +
--- 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 --- ++ + +
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+interface specification + +CGI - Common Gateway Interface +
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