regex(3) Library Functions Manual regex(3)
re_comp, re_exec - regular expression handler
The subroutine compiles a string into an internal form suitable for pattern matching. The subroutine checks the argument string against
the last string passed to
The subroutine returns 0 if the string s was compiled successfully; otherwise a string containing an error message is returned. If is
passed 0 or a null string, it returns without changing the currently compiled regular expression.
The subroutine returns 1 if the string s matches the last compiled regular expression, 0 if the string s failed to match the last compiled
regular expression, and -1 if the compiled regular expression was invalid (indicating an internal error).
The strings passed to both and may have trailing or embedded newline characters; they are terminated by nulls. The regular expressions
recognized are described in the manual entry for given the above difference.
The subroutine returns -1 for an internal error.
The subroutine returns one of the following strings if an error occurs:
No previous regular expression
Regular expression too long
too many () pairs
ed(1), ex(1), egrep(1), fgrep(1), grep(1)