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 #define _XOPEN_SOURCE 600
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <time.h>
  25 #include <inttypes.h>
  26
  27 int main(int argc, char** argv)
  28 {
  29     FILE *f;
  30     int count, maxburst, length;
  31
  32     if (argc < 4){
  33         printf("USAGE: trasher <filename> <count> <maxburst>\n");
  34         return 1;
  35     }
  36
  37     f= fopen(argv[1], "rb+");
  38     if (!f){
  39         perror(argv[1]);
  40         return 2;
  41     }
  42     count= atoi(argv[2]);
  43     maxburst= atoi(argv[3]);
  44
  45     srandom (time (0));
  46
  47     fseek(f, 0, SEEK_END);
  48     length= ftell(f);
  49     fseek(f, 0, SEEK_SET);
  50
  51     while(count--){
  52         int burst= 1 + random() * (uint64_t) (abs(maxburst)-1) / RAND_MAX;
  53         int pos= random() * (uint64_t) length / RAND_MAX;
  54         fseek(f, pos, SEEK_SET);
  55
  56         if(maxburst<0) burst= -maxburst;
  57
  58         if(pos + burst > length)
  59             continue;
  60
  61         while(burst--){
  62             int val= random() * 256ULL / RAND_MAX;
  63
  64             if(maxburst<0) val=0;
  65
  66             fwrite(&val, 1, 1, f);
  67         }
  68     }
  69
  70     return 0;
  71 }