src/utils/cas/lines.c

   1 /*
   2  *  This file is part of aMule.
   3  *
   4  *  This program is free software; you can redistribute it and/or modify
   5  *  it under the terms of the GNU General Public License as published by
   6  *  the Free Software Foundation; either version 2 of the License, or
   7  *  (at your option) any later version.
   8  *
   9  *  This program is distributed in the hope that it will be useful,
  10  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  *  GNU General Public License for more details.
  13  *
  14  *  You should have received a copy of the GNU General Public License
  15  *  along with this program; if not, write to the
  16  *  Free Software Foundation, Inc.,
  17  *  51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA
  18  */
  19
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <stdarg.h>
  23 #include <string.h>
  24
  25 #include "lines.h"
  26
  27 void CreateLine(char *lines[], int line, const char *format, ...)
  28 {
  29         /* Guess we need no more than 80 bytes. */
  30         int size = 100;
  31         char *p;
  32         char *tmp;
  33         va_list ap;
  34         if ((p = malloc(size)) == NULL) {
  35                 lines[line] = NULL;
  36                 return;
  37         }
  38         while (1) {
  39                 int n;
  40                 /* Try to print in the allocated space. */
  41                 va_start(ap, format);
  42                 n = vsnprintf(p, size, format, ap);
  43                 va_end(ap);
  44                 /* If that worked, set the line. */
  45                 if (n > -1 && n < size) {
  46                         break;
  47                 }
  48                 /* Else try again with more space. */
  49                 if (n > -1)     /* glibc 2.1 */
  50                         size = n+1;     /* precisely what is needed */
  51                 else            /* glibc 2.0 */
  52                         size *= 2;      /* twice the old size */
  53                 if ((tmp = realloc(p, size)) == NULL) {
  54                         free(p);
  55                         p = NULL;
  56                         break;
  57                 } else {
  58                         p = tmp;
  59                 }
  60         }
  61         lines[line] = p;
  62 }
  63
  64 void AppendToLine(char *lines[], int line, const char *text)
  65 {
  66         /* Are we trying to append to an empty line? */
  67         if (lines[line] == NULL)
  68                 CreateLine(lines, line, text);
  69         else {
  70                 /* Calculate the new required size... */
  71                 int size = strlen(lines[line]) + strlen(text) + 1;
  72                 if ((lines[line] = realloc(lines[line], size)) == NULL)
  73                         return;
  74                 /* ... and append the new text. */
  75                 strcat(lines[line], text);
  76         }
  77 }