perldoc tool provides documentation on language and core modules. To learn more about a module, use
perldoc module_name. For example,
perldoc CGI will display the following information about the CGI core module:
CGI - Handle Common Gateway Interface requests and responses
my $q = CGI->new;
CGI.pm is a stable, complete and mature solution for processing and preparing HTTP requests and responses. Major features including processing form submissions, file uploads, reading and writing cookies, query string generation and manipulation, and processing and preparing HTTP headers. Some HTML generation utilities are included as well.
There are two styles of programming with CGI.pm, an object-oriented style and a function-oriented style. In the object-oriented style you create one or more CGI objects and then use object methods to create the various elements of the page. Each CGI object starts out with the list of named parameters that were passed to your CGI script by the server.
For details on Perl functions, use
perldoc -f function_name . For example, perldoc -f split wil display the following information about the split function:
split Splits the string EXPR into a list of strings and returns that list. By default, empty leading fields are preserved, and empty trailing ones are deleted. (If all fields are empty, they are considered to be trailing.)
In scalar context, returns the number of fields found. In scalar and void context it splits into the @_ array. Use of split in scalar and void context is deprecated, however, because it clobbers your subroutine arguments.
If EXPR is omitted, splits the $_ string. If PATTERN is also omitted, splits on whitespace (after skipping any leading whitespace). Anything matching PATTERN is taken to be a delimiter separating the fields. (Note that the delimiter may be longer than one character.)