Synopsis:
   $regcomp(<regex pattern>)
   $regexec(<compiled pattern> <string>)
   $regerror(<compiled pattern>)
   $regfree(<compiled pattern>)

Technical:
   These functions are an interface to "regular expression" pattern matching:
   $regcomp() is used to "compile" a regular expression.  The return value
        is suitable for /assigning to an ircII variable.  Note that the
        return value of this function must be passed to the $regfree()
        function, to return the allocated resources for the compiled pattern.
        The compilation could fail: if you believe the compilation failed, you
        should call $regerror() to fetch the error.
   $regexec() is used to match a previously compiled pattern against a 
        text string.  The function returns 1 if the string is matched by the
        pattern, and 0 if it does not.
   $regerror() is used to fetch the error code for the most recently 
        attempted action on a previously compiled pattern.
   $regfree() is used to return the resources allocated to a compiled
        pattern.  Attempting to use a compiled pattern after it has been 
        passed to regfree is an error and may crash the client.  The
        function returns the FALSE value.

   If you neglect to regfree something that was returned by regcomp,
   then that will result in a memory leak.  The client cannot control this,
   and so if you use these functions, it is your duty to keep track of this.

   Passing a value to regexec, regerror, or regfree that was not
   previously returned from regcomp is an error and may crash the client.

Practical:
   Well, I can not give you any immediately practical uses for these functions.
   They are provided mostly for completeness because they were requested and
   they weren't that difficult to support.

Returns:
   $regcomp() returns an opaque r-value suitable for passing to the 
        other three functions.  The return value must be passed later to
        $regfree().
   $regexec() returns 0 or 1 depending on whether the match worked or not
   $regerror() returns the current error condition for a pattern
   $regfree() returns the false value.

See Also:
   assign(1); match(6); rmatch(6)