rexx/lstring/substr.c

   1 /*
   2  * $Header$
   3  * $Log$
   4  * Revision 1.1  2001/04/04 05:43:38  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 <string.h>
  13 #include <lstring.h>
  14
  15 /* --------------------------- Lsubstr -------------------------------- */
  16 /*    to       - Output Lstr                                            *
  17  *   from      - Input Lstr                                             *
  18  *   start     - an integer, can take values from [1,from length]       *
  19  *               if start<1 then start = 1                              *
  20  *   length    - negative value means rest of string (default)          *
  21  *               [1 - nnn] cuts string and pad's it if necessary.       *
  22  *    pad      - pad character                                          *
  23  * -------------------------------------------------------------------- */
  24 void
  25 Lsubstr(const PLstr to, const PLstr from,
  26         long start, long length, const char pad )
  27 {
  28         size_t  l;
  29
  30         L2STR(from);
  31
  32         start--;
  33         if (start<0) start = 0;
  34
  35         if (length<=0) {
  36                 if (length==0 || start>=LLEN(*from)) {
  37                         LZEROSTR(*to);
  38                         return;
  39                 }
  40                 length = LLEN(*from) - start;
  41         }
  42
  43         Lfx(to,(size_t)length);
  44
  45         if (start<LLEN(*from)) {
  46                 if (length+start>LLEN(*from)) {
  47                         l = LLEN(*from) - (size_t)start;
  48                         MEMMOVE( LSTR(*to), LSTR(*from)+start, l);
  49                         MEMSET( LSTR(*to)+l, pad, (size_t)length-l);
  50                 } else
  51                         MEMMOVE( LSTR(*to), LSTR(*from)+start, (size_t)length);
  52         } else
  53                 MEMSET(LSTR(*to),pad,(size_t)length);
  54
  55         LTYPE(*to) = LSTRING_TY;
  56         LLEN(*to) = (size_t)length;
  57 } /* Lstrsub */