BSD 4_3 release

[unix-history] / usr / src / usr.lib / libF77 / rindex_.c

/*
* Copyright (c) 1980 Regents of the University of California.
* All rights reserved.  The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
*
*      @(#)rindex_.c   5.2     6/7/85
*
* find last occurrence of substring in string
*
* calling sequence:
*      character*(*) substr, string
*      indx = rindex (string, substr)
* where:
*      indx will be the index of the first character of the last occurence
*      of substr in string, or zero if not found.
*/

long rindex_(str, substr, slen, sublen)
char *str, *substr; long slen, sublen;
{
       register char   *p = str + (slen - sublen);
       register char   *p1, *p2;
       register int    len;

       if (sublen == 0)
               return(0L);
       while (p >= str) {
               p1 = p;
               p2 = substr;
               len = sublen;
               while ( *p1++ == *p2++ && --len > 0) ;
               if ( len <= 0 )
                       return((long)(++p - str));
               p--;
       }
       return(0L);
}