REGEX(3-BSD)        RISC/os Reference Manual         REGEX(3-BSD)



NAME
     re_comp, re_exec - regular expression handler

SYNOPSIS
     char *recomp(s)
     char *s;

     reexec(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 \).









                        Printed 11/19/92                   Page 1