regex(3)                (BSD Compatibility Package)                regex(3)


   NAME
         regex, recomp, reexec - regular expression handler

   SYNOPSIS
         cc [ flag... ] file ... -lucb

         char *recomp(s)
         char *s;

         reexec(s)
         char *s;

   DESCRIPTION
         recomp compiles a string into an internal form suitable for pattern
         matching.  reexec checks the argument string against the last string
         passed to recomp.

         recomp returns a NULL pointer if the string s was compiled
         successfully; otherwise a string containing an error message is
         returned.  If recomp is passed 0 or a NULL string, it returns
         without changing the currently compiled regular expression.

         reexec 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 recomp and reexec may have trailing or
         embedded NEWLINE characters; they are terminated by NULL characters.
         The regular expressions recognized are described in the manual entry
         for ed(1), given the above difference.

   SEE ALSO
         ed(1), ex(1), grep(1) in the User's Reference Manual.
         regcmp(1), regexpr(3G), regcmp(3X), regexpr(5) in the Programmer's
         Reference Manual.

   RETURN VALUE
         reexec returns -1 for an internal error.

         recomp returns one of the following strings if an error occurs:

               No previous regular expression
               Regular expression too long
               unmatched \(
               missing ]
               too many \(\) pairs
               unmatched \)





   7/91                                                                 Page 1