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/*
* Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under both the BSD-style license (found in the
* LICENSE file in the root directory of this source tree) and the GPLv2 (found
* in the COPYING file in the root directory of this source tree).
* You may select, at your option, one of the above-listed licenses.
*/
#include <stdlib.h> // malloc, exit
#include <stdio.h> // printf
#include <string.h> // strerror
#include <errno.h> // errno
#include <sys/stat.h> // stat
#define ZSTD_STATIC_LINKING_ONLY // ZSTD_findDecompressedSize
#include <zstd.h> // presumes zstd library is installed
static off_t fsize_orDie(const char *filename)
{
struct stat st;
if (stat(filename, &st) == 0) return st.st_size;
/* error */
fprintf(stderr, "stat: %s : %s \n", filename, strerror(errno));
exit(1);
}
static FILE* fopen_orDie(const char *filename, const char *instruction)
{
FILE* const inFile = fopen(filename, instruction);
if (inFile) return inFile;
/* error */
fprintf(stderr, "fopen: %s : %s \n", filename, strerror(errno));
exit(2);
}
static void* malloc_orDie(size_t size)
{
void* const buff = malloc(size + !size); /* avoid allocating size of 0 : may return NULL (implementation dependent) */
if (buff) return buff;
/* error */
fprintf(stderr, "malloc: %s \n", strerror(errno));
exit(3);
}
static void* loadFile_orDie(const char* fileName, size_t* size)
{
off_t const buffSize = fsize_orDie(fileName);
FILE* const inFile = fopen_orDie(fileName, "rb");
void* const buffer = malloc_orDie(buffSize);
size_t const readSize = fread(buffer, 1, buffSize, inFile);
if (readSize != (size_t)buffSize) {
fprintf(stderr, "fread: %s : %s \n", fileName, strerror(errno));
exit(4);
}
fclose(inFile); /* can't fail (read only) */
*size = buffSize;
return buffer;
}
static void decompress(const char* fname)
{
size_t cSize;
void* const cBuff = loadFile_orDie(fname, &cSize);
unsigned long long const rSize = ZSTD_findDecompressedSize(cBuff, cSize);
if (rSize==ZSTD_CONTENTSIZE_ERROR) {
fprintf(stderr, "%s : it was not compressed by zstd.\n", fname);
exit(5);
} else if (rSize==ZSTD_CONTENTSIZE_UNKNOWN) {
fprintf(stderr,
"%s : original size unknown. Use streaming decompression instead.\n", fname);
exit(6);
}
void* const rBuff = malloc_orDie((size_t)rSize);
size_t const dSize = ZSTD_decompress(rBuff, rSize, cBuff, cSize);
if (dSize != rSize) {
fprintf(stderr, "error decoding %s : %s \n", fname, ZSTD_getErrorName(dSize));
exit(7);
}
/* success */
printf("%25s : %6u -> %7u \n", fname, (unsigned)cSize, (unsigned)rSize);
free(rBuff);
free(cBuff);
}
int main(int argc, const char** argv)
{
const char* const exeName = argv[0];
if (argc!=2) {
printf("wrong arguments\n");
printf("usage:\n");
printf("%s FILE\n", exeName);
return 1;
}
decompress(argv[1]);
printf("%s correctly decoded (in memory). \n", argv[1]);
return 0;
}
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