List of PHP regex functions based on PERL
FUNCTION DESCRIPTION
the preg_match() function The preg_match() function tests an expression against a pattern.
the preg_replace() function The preg_replace() function searches and replaces a string in a pattern.
the preg_split() function The preg_split() function splits a pattern and saves it in an array.

List of PHP regex functions based on POSIX
FUNCTION DESCRIPTION
the ereg() function The ereg() function tests an expression against a pattern.
the ereg_replace() function The ereg_replace() function searches and replaces a string in a pattern.
the split() function The split() function splits a pattern and saves it in an array.