/********************************************************************** * Copyright (c) Digital Equipment Corporation 1984, 1985, 1986. * * All Rights Reserved. * * Reference "/usr/src/COPYRIGHT" for applicable restrictions. * **********************************************************************/ static char Sccsid[]="@(#)index.c 3.0 4/22/86"; /* If `s2' is a substring of `s1' return the offset of the first occurrence of `s2' in `s1', else return -1. */ index(as1,as2) char *as1,*as2; { register char *s1,*s2,c; int offset; s1 = as1; s2 = as2; c = *s2; while (*s1) if (*s1++ == c) { offset = s1 - as1 - 1; s2++; while ((c = *s2++) == *s1++ && c) ; if (c == 0) return(offset); s1 = offset + as1 + 1; s2 = as2; c = *s2; } return(-1); }