/*** *strstr.c - search for one string inside another * * Copyright (c) 1985-1991, Microsoft Corporation. All rights reserved. * *Purpose: * defines strstr() - search for one string inside another * *Revision History: * 02-27-90 GJF Fixed calling type, #include , fixed * copyright. * 08-14-90 SBM Removed now redundant #include * 10-02-90 GJF New-style function declarator. * 03-14-94 GJF If string2 is empty, return string1. * *******************************************************************************/ #include #include /*** *char *strstr(string1, string2) - search for string2 in string1 * *Purpose: * finds the first occurrence of string2 in string1 * *Entry: * char *string1 - string to search in * char *string2 - string to search for * *Exit: * returns a pointer to the first occurrence of string2 in * string1, or NULL if string2 does not occur in string1 * *Uses: * *Exceptions: * *******************************************************************************/ char * _CALLTYPE1 strstr ( const char * str1, const char * str2 ) { char *cp = (char *) str1; char *s1, *s2; if ( !*str2 ) return(str1); while (*cp) { s1 = cp; s2 = (char *) str2; while ( *s1 && *s2 && !(*s1-*s2) ) s1++, s2++; if (!*s2) return(cp); cp++; } return(NULL); }