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tar: optional autodetection of gz/bz2 compressed tarballs.

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+130 bytes. Closes bug 992.
This commit is contained in:
Denis Vlasenko 2008-02-19 11:26:28 +00:00
parent a37e7134f7
commit 431a7c9c53
3 changed files with 94 additions and 33 deletions
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40
archival/Config.in
View File

@ -166,6 +166,14 @@ config FEATURE_TAR_CREATE
If you enable this option you'll be able to create
tar archives using the `-c' option.
config FEATURE_TAR_GZIP
bool "Enable -z option"
default y
depends on TAR
help
If you enable this option tar will be able to call gzip,
when creating or extracting tar gziped archives.
config FEATURE_TAR_BZIP2
bool "Enable -j option to handle .tar.bz2 files"
default n
@ -182,22 +190,6 @@ config FEATURE_TAR_LZMA
If you enable this option you'll be able to extract
archives compressed with lzma.
config FEATURE_TAR_FROM
bool "Enable -X (exclude from) and -T (include from) options)"
default n
depends on TAR
help
If you enable this option you'll be able to specify
a list of files to include or exclude from an archive.
config FEATURE_TAR_GZIP
bool "Enable -z option"
default y
depends on TAR
help
If you enable this option tar will be able to call gzip,
when creating or extracting tar gziped archives.
config FEATURE_TAR_COMPRESS
bool "Enable -Z option"
default n
@ -206,6 +198,22 @@ config FEATURE_TAR_COMPRESS
If you enable this option tar will be able to call uncompress,
when extracting .tar.Z archives.
config FEATURE_TAR_AUTODETECT
bool "Let tar autodetect gz/bz2 compresses tarballs"
default n
depends on FEATURE_TAR_GZIP || FEATURE_TAR_BZIP2
help
With this option tar can automatically detect gzip/bzip2 compressed
tarballs. Currently it works only on seekable streams.
config FEATURE_TAR_FROM
bool "Enable -X (exclude from) and -T (include from) options)"
default n
depends on TAR
help
If you enable this option you'll be able to specify
a list of files to include or exclude from an archive.
config FEATURE_TAR_OLDGNU_COMPATIBILITY
bool "Enable support for old tar header format"
default N

50
archival/libunarchive/get_header_tar.c
View File

@ -46,6 +46,9 @@ void BUG_tar_header_size(void);
char get_header_tar(archive_handle_t *archive_handle)
{
static smallint end;
#if ENABLE_FEATURE_TAR_AUTODETECT
static smallint not_first;
#endif
file_header_t *file_header = archive_handle->file_header;
struct {
@ -115,7 +118,7 @@ char get_header_tar(archive_handle_t *archive_handle)
* Read until the end to empty the pipe from gz or bz2
*/
while (full_read(archive_handle->src_fd, &tar, 512) == 512)
/* repeat */;
continue;
return EXIT_FAILURE;
}
end = 1;
@ -123,16 +126,49 @@ char get_header_tar(archive_handle_t *archive_handle)
}
end = 0;
/* Check header has valid magic, "ustar" is for the proper tar
* 0's are for the old tar format
*/
if (strncmp(tar.magic, "ustar", 5) != 0) {
#if ENABLE_FEATURE_TAR_OLDGNU_COMPATIBILITY
if (memcmp(tar.magic, "\0\0\0\0", 5) != 0)
/* Check header has valid magic, "ustar" is for the proper tar,
* five NULs are for the old tar format */
if (strncmp(tar.magic, "ustar", 5) != 0
&& (!ENABLE_FEATURE_TAR_OLDGNU_COMPATIBILITY
|| memcmp(tar.magic, "\0\0\0\0", 5) != 0)
) {
#if ENABLE_FEATURE_TAR_AUTODETECT
char (*get_header_ptr)(archive_handle_t *);
/* tar gz/bz autodetect: check for gz/bz2 magic.
* If it is the very first block, and we see the magic,
* we can switch to get_header_tar_gz/bz2/lzma().
* Needs seekable fd. I wish recv(MSG_PEEK) would work
* on any fd... */
if (not_first)
goto err;
#if ENABLE_FEATURE_TAR_GZIP
if (tar.name[0] == 0x1f && tar.name[1] == 0x8b) { /* gzip */
get_header_ptr = get_header_tar_gz;
} else
#endif
#if ENABLE_FEATURE_TAR_BZIP2
if (tar.name[0] == 'B' && tar.name[1] == 'Z'
&& tar.name[2] == 'h' && isdigit(tar.name[3])
) { /* bzip2 */
get_header_ptr = get_header_tar_bz2;
} else
#endif
goto err;
if (lseek(archive_handle->src_fd, -512, SEEK_CUR) != 0)
goto err;
while (get_header_ptr(archive_handle) == EXIT_SUCCESS)
continue;
return EXIT_FAILURE;
err:
#endif /* FEATURE_TAR_AUTODETECT */
bb_error_msg_and_die("invalid tar magic");
}
#if ENABLE_FEATURE_TAR_AUTODETECT
not_first = 1;
#endif
/* Do checksum on headers.
* POSIX says that checksum is done on unsigned bytes, but
* Sun and HP-UX gets it wrong... more details in

31
archival/tar.c
View File

@ -33,8 +33,17 @@
#define FNM_LEADING_DIR 0
#endif
#define block_buf bb_common_bufsiz1
#if !ENABLE_FEATURE_TAR_GZIP && !ENABLE_FEATURE_TAR_BZIP2
/* Do not pass gzip flag to writeTarFile() */
#define writeTarFile(tar_fd, verboseFlag, dereferenceFlag, include, exclude, gzip) \
writeTarFile(tar_fd, verboseFlag, dereferenceFlag, include, exclude)
#endif
#if ENABLE_FEATURE_TAR_CREATE
/* Tar file constants */
@ -514,18 +523,23 @@ static int writeTarFile(const int tar_fd, const int verboseFlag,
if (fstat(tbInfo.tarFd, &tbInfo.statBuf) < 0)
bb_perror_msg_and_die("cannot stat tar file");
if ((ENABLE_FEATURE_TAR_GZIP || ENABLE_FEATURE_TAR_BZIP2) && gzip) {
#if ENABLE_FEATURE_TAR_GZIP || ENABLE_FEATURE_TAR_BZIP2
if (gzip) {
#if ENABLE_FEATURE_TAR_GZIP && ENABLE_FEATURE_TAR_BZIP2
const char *zip_exec = (gzip == 1) ? "gzip" : "bzip2";
#elif ENABLE_FEATURE_TAR_GZIP
const char *zip_exec = "gzip";
#else /* only ENABLE_FEATURE_TAR_BZIP2 */
const char *zip_exec = "bzip2";
#endif
// On Linux, vfork never unpauses parent early, although standard
// allows for that. Do we want to waste bytes checking for it?
#define WAIT_FOR_CHILD 0
volatile int vfork_exec_errno = 0;
#if WAIT_FOR_CHILD
struct fd_pair gzipStatusPipe;
#endif
struct fd_pair gzipDataPipe;
const char *zip_exec = (gzip == 1) ? "gzip" : "bzip2";
xpiped_pair(gzipDataPipe);
#if WAIT_FOR_CHILD
xpiped_pair(gzipStatusPipe);
@ -584,6 +598,7 @@ static int writeTarFile(const int tar_fd, const int verboseFlag,
bb_perror_msg_and_die("cannot exec %s", zip_exec);
}
}
#endif
tbInfo.excludeList = exclude;
@ -934,11 +949,13 @@ int tar_main(int argc, char **argv)
/* create an archive */
if (opt & OPT_CREATE) {
#if ENABLE_FEATURE_TAR_GZIP || ENABLE_FEATURE_TAR_BZIP2
int zipMode = 0;
if (ENABLE_FEATURE_TAR_GZIP && get_header_ptr == get_header_tar_gz)
if (ENABLE_FEATURE_TAR_GZIP && (opt & OPT_GZIP))
zipMode = 1;
if (ENABLE_FEATURE_TAR_BZIP2 && get_header_ptr == get_header_tar_bz2)
if (ENABLE_FEATURE_TAR_BZIP2 && (opt & OPT_BZIP2))
zipMode = 2;
#endif
/* NB: writeTarFile() closes tar_handle->src_fd */
return writeTarFile(tar_handle->src_fd, verboseFlag, opt & OPT_DEREFERENCE,
tar_handle->accept,
@ -946,7 +963,7 @@ int tar_main(int argc, char **argv)
}
while (get_header_ptr(tar_handle) == EXIT_SUCCESS)
/* nothing */;
continue;
/* Check that every file that should have been extracted was */
while (tar_handle->accept) {