/* * Copyright (c) 2000, 2001, 2002, 2003, 2004, 2005, 2008, 2009 * The President and Fellows of Harvard College. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE UNIVERSITY AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE UNIVERSITY OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ /* * hash: Takes a file and computes a "hash" value by adding together all * the values in the file mod some largish prime. * * Once the basic system calls are complete, this should work on any * file the system supports. However, it's probably of most use for * testing your file system code. * * This should really be replaced with a real hash, like MD5 or SHA-1. */ #include <stdio.h> #include <unistd.h> #include <fcntl.h> #include <err.h> #ifdef HOST #include "hostcompat.h" #endif #define HASHP 104729 int main(int argc, char *argv[]) { int fd; char readbuf[1]; int j = 0; #ifdef HOST hostcompat_init(argc, argv); #endif if (argc != 2) { errx(1, "Usage: hash filename"); } fd = open(argv[1], O_RDONLY, 0664); if (fd<0) { err(1, "%s", argv[1]); } for (;;) { if (read(fd, readbuf, 1) <= 0) break; j = ((j*8) + (int) readbuf[0]) % HASHP; } close(fd); printf("Hash : %d\n", j); return 0; }