REGEX(3)
NAME
re_comp, re_exec − regular expression handler
USAGE
char *re_comp(s) char *s;
re_exec(s) char *s;
DESCRIPTION
Re_comp compiles a string into an internal form suitable for pattern matching. Re_exec checks the argument string against the last string passed to re_comp.
Re_comp returns zero if the string s was compiled successfully; otherwise it returns a string containing an error message. If re_comp is passed zero or a null string, it returns without changing the currently compiled regular expression.
Re_exec returns 1 if the string s matches the last compiled regular expression, zero 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).
A string passed to either re_comp or re_exec may have trailing or embedded newline characters, and is null-terminated. With that exception, recognized regular expressions are the ones described in the manual entry for ed(1).
DIAGNOSTICS
Re_exec returns -1 for an internal error.
Re_comp returns one of the following strings if an error occurs:
No previous regular expression, Regular expression too long unmatched \( missing ] too many \(\) pairs unmatched \)