/* * Copyright (c) 2007 Michael Niedermayer * * This file is part of Libav. * * Libav is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * Libav is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with Libav; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include <stdio.h> #include <stdlib.h> #include <inttypes.h> #include <errno.h> #include <string.h> static uint32_t state; static uint32_t ran(void) { return state = state * 1664525 + 1013904223; } int main(int argc, char **argv) { FILE *f; int count, maxburst, length; if (argc < 5) { printf("USAGE: trasher <filename> <count> <maxburst> <seed>\n"); return 1; } f = fopen(argv[1], "rb+"); if (!f) { perror(argv[1]); return 2; } count = atoi(argv[2]); maxburst = atoi(argv[3]); state = atoi(argv[4]); fseek(f, 0, SEEK_END); length = ftell(f); fseek(f, 0, SEEK_SET); while (count--) { int burst = 1 + ran() * (uint64_t) (abs(maxburst) - 1) / UINT32_MAX; int pos = ran() * (uint64_t) length / UINT32_MAX; fseek(f, pos, SEEK_SET); if (maxburst < 0) burst = -maxburst; if (pos + burst > length) continue; while (burst--) { int val = ran() * 256ULL / UINT32_MAX; if (maxburst < 0) val = 0; fwrite(&val, 1, 1, f); } } return 0; }