re_comp(3C)

NAME

     re_comp, re_exec - compile and execute regular expressions

SYNOPSIS

     #include <re_comp.h>

     char *re_comp(const char *string);

     int re_exec(const char *string);

DESCRIPTION

     The re_comp() function converts a regular expression  string
     (RE)  into  an  internal form suitable for pattern matching.
     The re_exec() function compares the string pointed to by the
     string  argument  with the last regular expression passed to
     re_comp().

     If re_comp() is called with a  null  pointer  argument,  the
     current regular expression remains unchanged.

     Strings passed to both re_comp() and re_exec() must be  ter-
     minated by a null byte, and may include NEWLINE characters.

     The re_comp() and re_exec() functions support simple regular
     expressions, which are defined on the regexp(5) manual page.
     The  regular expressions  of  the  form  \{m\},  \{m,\},  or
     \{m,n\} are not supported.

RETURN VALUES

     The re_comp() function  returns  a  null  pointer  when  the
     string  pointed  to  by  the string argument is successfully
     converted.  Otherwise, a pointer to  one  of  the  following
     error message strings is returned:

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

     Upon successful completion, re_exec() returns  1  if  string
     matches  the  last  compiled regular expression.  Otherwise,
     re_exec() returns 0 if string fails to match the  last  com-
     piled  regular  expression,  and  -1 if the compiled regular
     expression is invalid (indicating an internal error).

ERRORS

     No errors are defined.

USAGE

     For portability  to  implementations  conforming  to  X/Open
     standards prior to SUS, regcomp(3C) and regexec(3C) are pre-
     ferred to these functions.  See standards(5).

SEE ALSO

     grep(1), regcmp(1),  regcmp(3C),  regcomp(3C),  regexec(3C),
     regexpr(3GEN), regexp(5), standards(5)