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/*
* Copyright (c) International Business Machines Corp., 2014
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include "crc32.h"
void usage(void)
{
printf("Usage: crc32 infile\n");
}
int main(int argc, const char *argv[])
{
if (argc != 2) {
usage();
return 1;
}
int fd = open(argv[1], O_RDONLY);
if (fd < 0) {
printf("open %s: %s\n", argv[1], strerror(errno));
return 1;
}
struct stat stat;
int rc = fstat(fd, &stat);
if (rc < 0) {
printf("stat %s: %s\n", argv[1], strerror(errno));
return 1;
}
off_t filesize = stat.st_size;
void *in_buf = mmap(NULL, filesize, PROT_READ, MAP_PRIVATE, fd, 0);
if (in_buf == MAP_FAILED) {
/* FIXME could still try to use read().... */
printf("mmap %d failed: %s\n", filesize, strerror(errno));
return 1;
}
rc = close(fd);
if (rc < 0) {
printf("close %s: %s\n", argv[1], strerror(errno));
return 1;
}
unsigned long crc32 = memcpy32(NULL, in_buf, filesize);
printf("%#010lx", crc32), fflush(stdout);
return 0;
}
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