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