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CMake/Utilities/cmlibarchive/examples/minitar/minitar.c

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/*-
* This file is in the public domain.
* Do with it as you will.
*/
/*-
* This is a compact "tar" program whose primary goal is small size.
* Statically linked, it can be very small indeed. This serves a number
* of goals:
* o a testbed for libarchive (to check for link pollution),
* o a useful tool for space-constrained systems (boot floppies, etc),
* o a place to experiment with new implementation ideas for bsdtar,
* o a small program to demonstrate libarchive usage.
*
* Use the following macros to suppress features:
* NO_BZIP2 - Implies NO_BZIP2_CREATE and NO_BZIP2_EXTRACT
* NO_BZIP2_CREATE - Suppress bzip2 compression support.
* NO_BZIP2_EXTRACT - Suppress bzip2 auto-detection and decompression.
* NO_COMPRESS - Implies NO_COMPRESS_CREATE and NO_COMPRESS_EXTRACT
* NO_COMPRESS_CREATE - Suppress compress(1) compression support
* NO_COMPRESS_EXTRACT - Suppress compress(1) auto-detect and decompression.
* NO_CREATE - Suppress all archive creation support.
* NO_CPIO_EXTRACT - Suppress auto-detect and dearchiving of cpio archives.
* NO_GZIP - Implies NO_GZIP_CREATE and NO_GZIP_EXTRACT
* NO_GZIP_CREATE - Suppress gzip compression support.
* NO_GZIP_EXTRACT - Suppress gzip auto-detection and decompression.
* NO_LOOKUP - Try to avoid getpw/getgr routines, which can be very large
* NO_TAR_EXTRACT - Suppress tar extraction
*
* With all of the above macros defined (except NO_TAR_EXTRACT), you
* get a very small program that can recognize and extract essentially
* any uncompressed tar archive. On FreeBSD 5.1, this minimal program
* is under 64k, statically linked, which compares rather favorably to
* main(){printf("hello, world");}
* which is over 60k statically linked on the same operating system.
* Without any of the above macros, you get a static executable of
* about 180k with a lot of very sophisticated modern features.
* Obviously, it's trivial to add support for ISO, Zip, mtree,
* lzma/xz, etc. Just fill in the appropriate setup calls.
*/
#include <sys/types.h>
__FBSDID("$FreeBSD$");
#include <sys/stat.h>
#include <archive.h>
#include <archive_entry.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#ifndef NO_CREATE
#include "tree.h"
#endif
/*
* NO_CREATE implies NO_BZIP2_CREATE and NO_GZIP_CREATE and NO_COMPRESS_CREATE.
*/
#ifdef NO_CREATE
#undef NO_BZIP2_CREATE
#define NO_BZIP2_CREATE
#undef NO_COMPRESS_CREATE
#define NO_COMPRESS_CREATE
#undef NO_GZIP_CREATE
#define NO_GZIP_CREATE
#endif
/*
* The combination of NO_BZIP2_CREATE and NO_BZIP2_EXTRACT is
* equivalent to NO_BZIP2.
*/
#ifdef NO_BZIP2_CREATE
#ifdef NO_BZIP2_EXTRACT
#undef NO_BZIP2
#define NO_BZIP2
#endif
#endif
#ifdef NO_BZIP2
#undef NO_BZIP2_EXTRACT
#define NO_BZIP2_EXTRACT
#undef NO_BZIP2_CREATE
#define NO_BZIP2_CREATE
#endif
/*
* The combination of NO_COMPRESS_CREATE and NO_COMPRESS_EXTRACT is
* equivalent to NO_COMPRESS.
*/
#ifdef NO_COMPRESS_CREATE
#ifdef NO_COMPRESS_EXTRACT
#undef NO_COMPRESS
#define NO_COMPRESS
#endif
#endif
#ifdef NO_COMPRESS
#undef NO_COMPRESS_EXTRACT
#define NO_COMPRESS_EXTRACT
#undef NO_COMPRESS_CREATE
#define NO_COMPRESS_CREATE
#endif
/*
* The combination of NO_GZIP_CREATE and NO_GZIP_EXTRACT is
* equivalent to NO_GZIP.
*/
#ifdef NO_GZIP_CREATE
#ifdef NO_GZIP_EXTRACT
#undef NO_GZIP
#define NO_GZIP
#endif
#endif
#ifdef NO_GZIP
#undef NO_GZIP_EXTRACT
#define NO_GZIP_EXTRACT
#undef NO_GZIP_CREATE
#define NO_GZIP_CREATE
#endif
#ifndef NO_CREATE
static void create(const char *filename, int compress, const char **argv);
#endif
static void errmsg(const char *);
static void extract(const char *filename, int do_extract, int flags);
static int copy_data(struct archive *, struct archive *);
static void msg(const char *);
static void usage(void);
static int verbose = 0;
int
main(int argc, const char **argv)
{
const char *filename = NULL;
int compress, flags, mode, opt;
(void)argc;
mode = 'x';
verbose = 0;
compress = '\0';
flags = ARCHIVE_EXTRACT_TIME;
/* Among other sins, getopt(3) pulls in printf(3). */
while (*++argv != NULL && **argv == '-') {
const char *p = *argv + 1;
while ((opt = *p++) != '\0') {
switch (opt) {
#ifndef NO_CREATE
case 'c':
mode = opt;
break;
#endif
case 'f':
if (*p != '\0')
filename = p;
else
filename = *++argv;
p += strlen(p);
break;
#ifndef NO_BZIP2_CREATE
case 'j':
compress = opt;
break;
#endif
case 'p':
flags |= ARCHIVE_EXTRACT_PERM;
flags |= ARCHIVE_EXTRACT_ACL;
flags |= ARCHIVE_EXTRACT_FFLAGS;
break;
case 't':
mode = opt;
break;
case 'v':
verbose++;
break;
case 'x':
mode = opt;
break;
#ifndef NO_BZIP2_CREATE
case 'y':
compress = opt;
break;
#endif
#ifndef NO_COMPRESS_CREATE
case 'Z':
compress = opt;
break;
#endif
#ifndef NO_GZIP_CREATE
case 'z':
compress = opt;
break;
#endif
default:
usage();
}
}
}
switch (mode) {
#ifndef NO_CREATE
case 'c':
create(filename, compress, argv);
break;
#endif
case 't':
extract(filename, 0, flags);
break;
case 'x':
extract(filename, 1, flags);
break;
}
return (0);
}
#ifndef NO_CREATE
static char buff[16384];
static void
create(const char *filename, int compress, const char **argv)
{
struct archive *a;
struct archive *disk;
struct archive_entry *entry;
ssize_t len;
int fd;
a = archive_write_new();
switch (compress) {
#ifndef NO_BZIP2_CREATE
case 'j': case 'y':
archive_write_set_compression_bzip2(a);
break;
#endif
#ifndef NO_COMPRESS_CREATE
case 'Z':
archive_write_set_compression_compress(a);
break;
#endif
#ifndef NO_GZIP_CREATE
case 'z':
archive_write_set_compression_gzip(a);
break;
#endif
default:
archive_write_set_compression_none(a);
break;
}
archive_write_set_format_ustar(a);
if (strcmp(filename, "-") == 0)
filename = NULL;
archive_write_open_file(a, filename);
disk = archive_read_disk_new();
#ifndef NO_LOOKUP
archive_read_disk_set_standard_lookup(disk);
#endif
while (*argv != NULL) {
struct tree *t = tree_open(*argv);
while (tree_next(t)) {
entry = archive_entry_new();
archive_entry_set_pathname(entry, tree_current_path(t));
archive_read_disk_entry_from_file(disk, entry, -1,
tree_current_stat(t));
if (verbose) {
msg("a ");
msg(tree_current_path(t));
}
archive_write_header(a, entry);
fd = open(tree_current_access_path(t), O_RDONLY);
len = read(fd, buff, sizeof(buff));
while (len > 0) {
archive_write_data(a, buff, len);
len = read(fd, buff, sizeof(buff));
}
close(fd);
archive_entry_free(entry);
if (verbose)
msg("\n");
}
argv++;
}
archive_write_close(a);
archive_write_finish(a);
}
#endif
static void
extract(const char *filename, int do_extract, int flags)
{
struct archive *a;
struct archive *ext;
struct archive_entry *entry;
int r;
a = archive_read_new();
ext = archive_write_disk_new();
archive_write_disk_set_options(ext, flags);
#ifndef NO_BZIP2_EXTRACT
archive_read_support_compression_bzip2(a);
#endif
#ifndef NO_GZIP_EXTRACT
archive_read_support_compression_gzip(a);
#endif
#ifndef NO_COMPRESS_EXTRACT
archive_read_support_compression_compress(a);
#endif
#ifndef NO_TAR_EXTRACT
archive_read_support_format_tar(a);
#endif
#ifndef NO_CPIO_EXTRACT
archive_read_support_format_cpio(a);
#endif
#ifndef NO_LOOKUP
archive_write_disk_set_standard_lookup(ext);
#endif
if (filename != NULL && strcmp(filename, "-") == 0)
filename = NULL;
if ((r = archive_read_open_file(a, filename, 10240))) {
errmsg(archive_error_string(a));
errmsg("\n");
exit(r);
}
for (;;) {
r = archive_read_next_header(a, &entry);
if (r == ARCHIVE_EOF)
break;
if (r != ARCHIVE_OK) {
errmsg(archive_error_string(a));
errmsg("\n");
exit(1);
}
if (verbose && do_extract)
msg("x ");
if (verbose || !do_extract)
msg(archive_entry_pathname(entry));
if (do_extract) {
r = archive_write_header(ext, entry);
if (r != ARCHIVE_OK)
errmsg(archive_error_string(a));
else
copy_data(a, ext);
}
if (verbose || !do_extract)
msg("\n");
}
archive_read_close(a);
archive_read_finish(a);
exit(0);
}
static int
copy_data(struct archive *ar, struct archive *aw)
{
int r;
const void *buff;
size_t size;
off_t offset;
for (;;) {
r = archive_read_data_block(ar, &buff, &size, &offset);
if (r == ARCHIVE_EOF) {
errmsg(archive_error_string(ar));
return (ARCHIVE_OK);
}
if (r != ARCHIVE_OK)
return (r);
r = archive_write_data_block(aw, buff, size, offset);
if (r != ARCHIVE_OK) {
errmsg(archive_error_string(ar));
return (r);
}
}
}
static void
msg(const char *m)
{
write(1, m, strlen(m));
}
static void
errmsg(const char *m)
{
write(2, m, strlen(m));
}
static void
usage(void)
{
/* Many program options depend on compile options. */
const char *m = "Usage: minitar [-"
#ifndef NO_CREATE
"c"
#endif
#ifndef NO_BZIP2
"j"
#endif
"tvx"
#ifndef NO_BZIP2
"y"
#endif
#ifndef NO_COMPRESS
"Z"
#endif
#ifndef NO_GZIP
"z"
#endif
"] [-f file] [file]\n";
errmsg(m);
exit(1);
}
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