trasher.c 1.9 KB

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  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. #include <stdio.h>
  21. #include <stdlib.h>
  22. #include <inttypes.h>
  23. static uint32_t state;
  24. static uint32_t ran(void)
  25. {
  26. return state = state * 1664525 + 1013904223;
  27. }
  28. int main(int argc, char **argv)
  29. {
  30. FILE *f;
  31. int count, maxburst, length;
  32. if (argc < 5) {
  33. printf("USAGE: trasher <filename> <count> <maxburst> <seed>\n");
  34. return 1;
  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. state = atoi(argv[4]);
  44. fseek(f, 0, SEEK_END);
  45. length = ftell(f);
  46. fseek(f, 0, SEEK_SET);
  47. while (count--) {
  48. int burst = 1 + ran() * (uint64_t) (abs(maxburst) - 1) / UINT32_MAX;
  49. int pos = ran() * (uint64_t) length / UINT32_MAX;
  50. fseek(f, pos, SEEK_SET);
  51. if (maxburst < 0)
  52. burst = -maxburst;
  53. if (pos + burst > length)
  54. continue;
  55. while (burst--) {
  56. int val = ran() * 256ULL / UINT32_MAX;
  57. if (maxburst < 0)
  58. val = 0;
  59. fwrite(&val, 1, 1, f);
  60. }
  61. }
  62. return 0;
  63. }