busybox/archival/libunarchive/get_header_tar_gz.c
Denis Vlasenko 0381d422d9 dpkg_deb: slight code shrink
ar: reuse existing ar unpacking code
get_header_tar: handle autodetection for tiny .tar.gz files too
unarchive.h: do not include CONFIGed out things

function                                             old     new   delta
get_header_tar                                      1521    1534     +13
dpkg_deb_main                                        400     380     -20
ar_main                                              260     196     -64
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/2 up/down: 13/-84)            Total: -71 bytes
2008-07-10 23:06:00 +00:00

37 lines
991 B
C

/* vi: set sw=4 ts=4: */
/*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
#include "libbb.h"
#include "unarchive.h"
char FAST_FUNC get_header_tar_gz(archive_handle_t *archive_handle)
{
#if BB_MMU
unsigned char magic[2];
#endif
/* Can't lseek over pipes */
archive_handle->seek = seek_by_read;
/* Check gzip magic only if open_transformer will invoke unpack_gz_stream (MMU case).
* Otherwise, it will invoke an external helper "gunzip -cf" (NOMMU case) which will
* need the header. */
#if BB_MMU
xread(archive_handle->src_fd, &magic, 2);
/* Can skip this check, but error message will be less clear */
if ((magic[0] != 0x1f) || (magic[1] != 0x8b)) {
bb_error_msg_and_die("invalid gzip magic");
}
#endif
open_transformer(archive_handle->src_fd, unpack_gz_stream, "gunzip");
archive_handle->offset = 0;
while (get_header_tar(archive_handle) == EXIT_SUCCESS)
continue;
/* Can only do one file at a time */
return EXIT_FAILURE;
}