coreutils/lib/strstr.c
1992-10-31 20:42:48 +00:00

50 lines
1.4 KiB
C

/* strstr.c -- return the offset of one string within another
Copyright (C) 1989, 1990 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
/* Author:
Mike Rendell Department of Computer Science
michael@garfield.mun.edu Memorial University of Newfoundland
..!uunet!garfield!michael St. John's, Nfld., Canada
(709) 737-4550 A1C 5S7
*/
/* Return the starting address of string S2 in S1;
return 0 if it is not found. */
char *
strstr (s1, s2)
char *s1;
char *s2;
{
int i;
char *p1;
char *p2;
char *s = s1;
for (p2 = s2, i = 0; *s; p2 = s2, i++, s++)
{
for (p1 = s; *p1 && *p2 && *p1 == *p2; p1++, p2++)
;
if (!*p2)
break;
}
if (!*p2)
return s1 + i;
return 0;
}