runestrstr.c (1221B)
1 /* 2 * The authors of this software are Rob Pike and Ken Thompson. 3 * Copyright (c) 2002 by Lucent Technologies. 4 * Permission to use, copy, modify, and distribute this software for any 5 * purpose without fee is hereby granted, provided that this entire notice 6 * is included in all copies of any software which is or includes a copy 7 * or modification of this software and in all copies of the supporting 8 * documentation for such software. 9 * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED 10 * WARRANTY. IN PARTICULAR, NEITHER THE AUTHORS NOR LUCENT TECHNOLOGIES MAKE 11 * ANY REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY 12 * OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE. 13 */ 14 #include "plan9.h" 15 #include "utf.h" 16 17 #include <stdarg.h> 18 #include <string.h> 19 20 /* 21 * Return pointer to first occurrence of s2 in s1, 22 * 0 if none 23 */ 24 Rune* runestrstr(Rune* s1, Rune* s2) { 25 Rune * p, *pa, *pb; 26 unsigned int c0, c; 27 28 c0 = *s2; 29 if (c0 == 0) 30 return s1; 31 s2++; 32 for (p = runestrchr(s1, c0); p; p = runestrchr(p + 1, c0)) { 33 pa = p; 34 for (pb = s2;; pb++) { 35 c = *pb; 36 if (c == 0) 37 return p; 38 if (c != *++pa) 39 break; 40 } 41 } 42 return 0; 43 }