FFmpeg
ffhash.c

This example is a simple command line application that takes one or more arguments. It demonstrates a typical use of the hashing API with allocation, initialization, updating, and finalizing.

/*
* Copyright (c) 2002 Fabrice Bellard
* Copyright (c) 2013 Michael Niedermayer
* Copyright (c) 2013 James Almer
*
* This file is part of FFmpeg.
*
* FFmpeg 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.
*
* FFmpeg 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 FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "config.h"
#include "libavutil/hash.h"
#include "libavutil/mem.h"
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <sys/stat.h>
#if HAVE_IO_H
#include <io.h>
#endif
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#define SIZE 65536
static struct AVHashContext *hash;
static int out_b64;
static void usage(void)
{
int i = 0;
const char *name;
printf("usage: ffhash [b64:]algorithm [input]...\n");
printf("Supported hash algorithms:");
do {
name = av_hash_names(i);
if (name)
printf(" %s", name);
i++;
} while(name);
printf("\n");
}
static void finish(void)
{
char res[2 * AV_HASH_MAX_SIZE + 4];
printf("%s=", av_hash_get_name(hash));
if (out_b64) {
av_hash_final_b64(hash, res, sizeof(res));
printf("b64:%s", res);
} else {
av_hash_final_hex(hash, res, sizeof(res));
printf("0x%s", res);
}
}
static int check(char *file)
{
int fd, flags = O_RDONLY;
int ret = 0;
#ifdef O_BINARY
flags |= O_BINARY;
#endif
if (file) fd = open(file, flags);
else fd = 0;
if (fd == -1) {
printf("%s=OPEN-FAILED: %s:", av_hash_get_name(hash), strerror(errno));
ret = 1;
goto end;
}
av_hash_init(hash);
for (;;) {
int size = read(fd, buffer, SIZE);
if (size < 0) {
int err = errno;
close(fd);
finish();
printf("+READ-FAILED: %s", strerror(err));
ret = 2;
goto end;
} else if(!size)
break;
av_hash_update(hash, buffer, size);
}
close(fd);
finish();
if (file)
printf(" *%s", file);
printf("\n");
return ret;
}
int main(int argc, char **argv)
{
int i;
int ret = 0;
const char *hash_name;
if (argc == 1) {
usage();
return 0;
}
hash_name = argv[1];
out_b64 = av_strstart(hash_name, "b64:", &hash_name);
if ((ret = av_hash_alloc(&hash, hash_name)) < 0) {
switch(ret) {
case AVERROR(EINVAL):
printf("Invalid hash type: %s\n", hash_name);
break;
case AVERROR(ENOMEM):
printf("%s\n", strerror(errno));
break;
}
return 1;
}
for (i = 2; i < argc; i++)
ret |= check(argv[i]);
if (argc < 3)
ret |= check(NULL);
av_hash_freep(&hash);
return ret;
}