source/strary.c

   1 /*
   2         Copyright (C) 2006 by Jonas Kramer
   3         Copyright (C) 2006 by Bart Trojanowski <bart@jukie.net>
   4
   5         Published under the terms of the GNU General Public License (GPL).
   6 */
   7
   8 #define _GNU_SOURCE
   9
  10
  11 #include <stdio.h>
  12 #include <stdlib.h>
  13 #include <string.h>
  14 #include <sys/time.h>
  15 #include <sys/types.h>
  16 #include <unistd.h>
  17 #include <stdarg.h>
  18 #include <assert.h>
  19
  20 #include "compatibility.h"
  21 #include "strary.h"
  22
  23
  24 /* Counts the elements of a NULL-terminated array of strings. */
  25 unsigned count(char ** list) {
  26         unsigned n = 0;
  27
  28         if(list != NULL)
  29                 while(list[n] != NULL)
  30                         ++n;
  31
  32         return n;
  33 }
  34
  35 /* Appends a string to a NULL-terminated array of strings. */
  36 char ** append(char ** list, const char * string) {
  37         unsigned size = count(list);
  38
  39         list = realloc(list, sizeof(char *) * (size + 2));
  40
  41         list[size++] = strdup(string);
  42         list[size] = NULL;
  43
  44         return list;
  45 }
  46
  47 /*
  48         Merge two arrays of strings. If the third parameter is zero,
  49         the elements of the second array and the array itself are freed.
  50 */
  51 char ** merge(char ** list, char ** appendix, int keep) {
  52         unsigned size = count(list), i;
  53
  54         for(i = 0; appendix && appendix[i] != NULL; ++i) {
  55                 list = realloc(list, sizeof(char *) * (size + 2));
  56                 list[size++] = strdup(appendix[i]);
  57                 list[size] = NULL;
  58
  59                 if(!keep)
  60                         free(appendix[i]);
  61         }
  62
  63         if(appendix != NULL && !keep)
  64                 free(appendix);
  65
  66         return list;
  67 }
  68
  69 /* Free a NULL-terminated array of strings. */
  70 void purge(char ** list) {
  71         unsigned i = 0;
  72
  73         if(list != NULL) {
  74                 while(list[i] != NULL)
  75                         free(list[i++]);
  76
  77                 free(list);
  78         }
  79 }
  80
  81 /*
  82         Merge strings of an array to one big string. If the second argument is
  83   false, the list is purged.
  84 */
  85 char * join(char ** list, int keep) {
  86         unsigned i = 0, length = 0;
  87         char * result = NULL;
  88
  89         if(list != NULL) {
  90                 while(list[i] != NULL) {
  91                         result = realloc(result, sizeof(char) * (length + strlen(list[i]) + 1));
  92
  93                         strcpy(result + length, list[i]);
  94                         length += strlen(list[i]);
  95                         result[length] = 0;
  96
  97                         ++i;
  98                 }
  99
 100                 if(!keep)
 101                         purge(list);
 102         }
 103
 104         return result;
 105 }