iTP Secure WebServer System Administrator's Guide (iTPWebSvr 6.0+)

Using Common Gateway Interface (CGI) Programs
iTP Secure WebServer System Administrator’s Guide—523346-002
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HTML Forms
HTML Forms
Input data can be passed to CGI programs through input parameters constructed from
data items entered into HTML forms. These parameters are read by CGI programs on
standard input.
Each data item entered into an HTML form is assigned to a value-name. The resulting
names and their values then are used to construct input parameters formatted as
follows:
name=value&name=value...&name=value
where:
•
A space in a value is replaced with a plus sign (+).
•
An equals sign (=) assigns a value to a specific name.
•
An ampersand (&) separates individual parameters.
For example, if a user name (John J. Smith) and an e-mail address
([e-mail]) are entered into an HTML form as input, these data items would
be formatted into input parameters as follows:
NAME=John+J.+Smith&EMAIL=[e-mail]
The input parameters must be entered exactly as required.
The environment variable CONTENT_LENGTH specifies the number of bytes on
standard input.
For detailed information about processing forms input parameters, consult an
appropriate HTML resource.
Returning Output
Any output a CGI program writes to standard output is passed by the server to the web
client. This output has three components:
•
One or more HTTP response headers
These headers contain descriptive information about the server response to a
request, such as the content (data) type, the number of bytes, and the expiration
time.
•
A blank line
This blank line is mandatory, even no content follows it. This requirement is
imposed by RFC 822; to see RFC 822, use the following URL:
http://www.cis.ohio-state.edu/htbin/rfc/rfc822.html