rexx/lstring/index.c

   1 /*
   2  * $Header$
   3  * $Log$
   4  * Revision 1.1  2001/04/04 05:43:37  wang
   5  * First commit: compiles on Linux, Amiga, Windows, Windows CE, generic gcc
   6  *
   7  * Revision 1.1  1998/07/02 17:18:00  bnv
   8  * Initial Version
   9  *
  10  */
  11
  12 #include <lstring.h>
  13
  14 /* ----------------- Lindex ---------------------- */
  15 /* haystack   - Lstr where to search               *
  16  *  needle    - Lstr to search                     *
  17  *    p       - starting position [1,haystack len] *
  18  *              if p < 1 then p = 1                *
  19  * returns  0 (NOTFOUND) is needle is not found    *
  20  * else returns position [1,haystack len]          *
  21  * ----------------------------------------------- */
  22 long
  23 Lindex( const PLstr haystack, const PLstr needle, long p)
  24 {
  25         long    n,lp;
  26
  27         p--;            /* for C string offset = 0, Rexx=1 */
  28         if (p<0) p = 0;
  29
  30         L2STR(haystack);
  31         L2STR(needle);
  32
  33         if (!LLEN(*needle)) {
  34                 if (!LLEN(*haystack)) return LNOTFOUND;
  35                 return p+1;
  36         }
  37         if (LLEN(*needle) > LLEN(*haystack)) return LNOTFOUND;
  38         lp = p-1;
  39         do {
  40                 n = 0; p = lp+1;
  41                 if (p >= LLEN(*haystack)) return LNOTFOUND;
  42                 while (LSTR(*haystack)[p] != LSTR(*needle)[0]) {
  43                         p++;
  44                         if (p >= LLEN(*haystack)) return LNOTFOUND;
  45                 }
  46                 lp = p;
  47                 while ( (LSTR(*haystack)[p]==LSTR(*needle)[n]) && (n<LLEN(*needle))) {
  48                         if ((++n) >= LLEN(*needle)) return lp+1;
  49                         p++;
  50                         if (p >= LLEN(*haystack)) return LNOTFOUND;
  51                 }
  52         } while (n<LLEN(*needle));
  53         return lp+1;
  54 } /* Lindex */