regex_bsd(3B)

NAME
     re_comp, re_exec - regular expression handler

SYNOPSIS
     #include unistd.h

     char *re_comp(const char *s);

     int re_exec(const 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.  However, re_comp does not handle range regular
     expressions (\{m,n\}) supported by ed(1) and regcmp(3G).

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 \)

SEE ALSO
     ed(1), ex(1), egrep(1), fgrep(1), grep(1), regcmp(3G).