tools/trasher.c

   1 /*
   2  * Copyright (c) 2007 Michael Niedermayer
   3  *
   4  * This file is part of FFmpeg.
   5  *
   6  * FFmpeg is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * FFmpeg is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with FFmpeg; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <time.h>
  24 #include <inttypes.h>
  25
  26 int main(int argc, char** argv)
  27 {
  28     FILE *f;
  29     int count, maxburst, length;
  30
  31     if (argc < 4){
  32         printf("USAGE: trasher <filename> <count> <maxburst>\n");
  33         return 1;
  34     }
  35
  36     f= fopen(argv[1], "rb+");
  37     if (!f){
  38         perror(argv[1]);
  39         return 2;
  40     }
  41     count= atoi(argv[2]);
  42     maxburst= atoi(argv[3]);
  43
  44     srandom (time (0));
  45
  46     fseek(f, 0, SEEK_END);
  47     length= ftell(f);
  48     fseek(f, 0, SEEK_SET);
  49
  50     while(count--){
  51         int burst= 1 + random() * (uint64_t) (abs(maxburst)-1) / RAND_MAX;
  52         int pos= random() * (uint64_t) length / RAND_MAX;
  53         fseek(f, pos, SEEK_SET);
  54
  55         if(maxburst<0) burst= -maxburst;
  56
  57         if(pos + burst > length)
  58             continue;
  59
  60         while(burst--){
  61             int val= random() * 256ULL / RAND_MAX;
  62
  63             if(maxburst<0) val=0;
  64
  65             fwrite(&val, 1, 1, f);
  66         }
  67     }
  68
  69     return 0;
  70 }