RE_COMP(3) UNIX Programmer’s Manual RE_COMP(3)

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
This interface is made obsolete by regex(3).

The re_comp() function compiles a string into an internal form suitable
for pattern matching. The re_exec() function checks the argument string
against the last string passed to re_comp().

The re_comp() function returns 0 if the string s was compiled successful-
ly; 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.

The re_exec() function returns 1 if the string s matches the last com-
piled regular expression, 0 if the string s failed to match the last com-
piled 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 NULs. The regular ex-
pressions recognized are described in the manual entry for ed(1), given
the above difference.

DIAGNOSTICS
The re_exec() function returns -1 for an internal error.

The re_comp() function 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), regex(3)

HISTORY
The re_comp() and re_exec() functions appeared in 4.0BSD.

BSD Experimental June 4, 1993 1