Search the directory to find matches for the
the specified pattern.
Parameter
$pattern - a string containing the pattern
to search the directory for.
$dirpath - a string containing the
directory path to search.
$pattern_type - a string containing the type
of pattern matching functions to use (can either be 'php' or 'perl').
The format of the $pattern depends on the
$pattern_type-value. If this value is
'php', then the pattern has to follow the
conventions of the eregi_*-functions, else if the value
'perl', then follow the preg_*-patternformat.
It is recommanded to use 'perl', because this
is faster.