commands/aal/long2str.c

   1 /* $Header$ */
   2 /*
   3  * (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands.
   4  * See the copyright notice in the ACK home directory, in the file "Copyright".
   5  */
   6 /* Integer to String translator
   7         -> base is a value from [-16,-2] V [2,16]
   8         -> base < 0: see 'val' as unsigned value
   9         -> no checks for buffer overflow and illegal parameters
  10         (1985, EHB)
  11 */
  12
  13 #define MAXWIDTH 32
  14
  15 char *
  16 long2str(val, base)
  17         register long val;
  18         register base;
  19 {
  20         static char numbuf[MAXWIDTH];
  21         static char vec[] = "0123456789ABCDEF";
  22         register char *p = &numbuf[MAXWIDTH];
  23         int sign = (base > 0);
  24
  25         *--p = '\0';            /* null-terminate string        */
  26         if (val) {
  27                 if (base > 0) {
  28                         if (val < 0L) {
  29                                 long v1 = -val;
  30                                 if (v1 == val)
  31                                         goto overflow;
  32                                 val = v1;
  33                         }
  34                         else
  35                                 sign = 0;
  36                 }
  37                 else
  38                 if (base < 0) {                 /* unsigned */
  39                         base = -base;
  40                         if (val < 0L) { /* taken from Amoeba src */
  41                                 register mod, i;
  42                         overflow:
  43                                 mod = 0;
  44                                 for (i = 0; i < 8 * sizeof val; i++) {
  45                                         mod <<= 1;
  46                                         if (val < 0)
  47                                                 mod++;
  48                                         val <<= 1;
  49                                         if (mod >= base) {
  50                                                 mod -= base;
  51                                                 val++;
  52                                         }
  53                                 }
  54                                 *--p = vec[mod];
  55                         }
  56                 }
  57                 do {
  58                         *--p = vec[(int) (val % base)];
  59                         val /= base;
  60                 } while (val != 0L);
  61                 if (sign)
  62                         *--p = '-';     /* don't forget it !!   */
  63         }
  64         else
  65                 *--p = '0';             /* just a simple 0      */
  66         return p;
  67 }