REGEX(3)                             BSD                              REGEX(3)



NAME
     re_comp, re_exec - regular expression handler

SYNOPSIS
     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 0 if the string s was compiled successfully; otherwise a
     string containing an error message is returned. If re_comp is passed 0 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, 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 re_comp and re_exec may have trailing or
     embedded newline characters; they are terminated by nulls.  The regular
     expressions recognized are described in the manual entry for ed(1), given
     the above difference.

SEE ALSO
     ed(1), ex(1), egrep(1), fgrep(1), grep(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 \).