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-rw-r--r--archival/libunarchive/data_extract_all.c5
-rw-r--r--archival/tar.c13
-rw-r--r--include/unarchive.h3
-rwxr-xr-xtestsuite/tar.tests13
4 files changed, 30 insertions, 4 deletions
diff --git a/archival/libunarchive/data_extract_all.c b/archival/libunarchive/data_extract_all.c
index ae242df..874d37d 100644
--- a/archival/libunarchive/data_extract_all.c
+++ b/archival/libunarchive/data_extract_all.c
@@ -72,8 +72,11 @@ void FAST_FUNC data_extract_all(archive_handle_t *archive_handle)
switch (file_header->mode & S_IFMT) {
case S_IFREG: {
/* Regular file */
+ int flags = O_WRONLY | O_CREAT | O_EXCL;
+ if (archive_handle->ah_flags & ARCHIVE_O_TRUNC)
+ flags = O_WRONLY | O_CREAT | O_TRUNC;
dst_fd = xopen3(file_header->name,
- O_WRONLY | O_CREAT | O_EXCL,
+ flags,
file_header->mode
);
bb_copyfd_exact_size(archive_handle->src_fd, dst_fd, file_header->size);
diff --git a/archival/tar.c b/archival/tar.c
index 7ec101d..5994d89 100644
--- a/archival/tar.c
+++ b/archival/tar.c
@@ -751,6 +751,7 @@ enum {
#if ENABLE_FEATURE_TAR_LONG_OPTIONS
OPTBIT_NUMERIC_OWNER,
OPTBIT_NOPRESERVE_PERM,
+ OPTBIT_OVERWRITE,
#endif
OPT_TEST = 1 << 0, // t
OPT_EXTRACT = 1 << 1, // x
@@ -771,6 +772,7 @@ enum {
OPT_COMPRESS = IF_FEATURE_SEAMLESS_Z( (1 << OPTBIT_COMPRESS )) + 0, // Z
OPT_NUMERIC_OWNER = IF_FEATURE_TAR_LONG_OPTIONS((1 << OPTBIT_NUMERIC_OWNER )) + 0, // numeric-owner
OPT_NOPRESERVE_PERM = IF_FEATURE_TAR_LONG_OPTIONS((1 << OPTBIT_NOPRESERVE_PERM)) + 0, // no-same-permissions
+ OPT_OVERWRITE = IF_FEATURE_TAR_LONG_OPTIONS((1 << OPTBIT_OVERWRITE )) + 0, // overwrite
};
#if ENABLE_FEATURE_TAR_LONG_OPTIONS
static const char tar_longopts[] ALIGN1 =
@@ -807,9 +809,11 @@ static const char tar_longopts[] ALIGN1 =
"compress\0" No_argument "Z"
# endif
/* use numeric uid/gid from tar header, not textual */
- "numeric-owner\0" No_argument "\xfd"
+ "numeric-owner\0" No_argument "\xfc"
/* do not restore mode */
- "no-same-permissions\0" No_argument "\xfe"
+ "no-same-permissions\0" No_argument "\xfd"
+ /* on unpack, open with O_TRUNC and !O_EXCL */
+ "overwrite\0" No_argument "\xfe"
/* --exclude takes next bit position in option mask, */
/* therefore we have to put it _after_ --no-same-permissions */
# if ENABLE_FEATURE_TAR_FROM
@@ -924,6 +928,11 @@ int tar_main(int argc UNUSED_PARAM, char **argv)
if (opt & OPT_NOPRESERVE_PERM)
tar_handle->ah_flags |= ARCHIVE_DONT_RESTORE_PERM;
+ if (opt & OPT_OVERWRITE) {
+ tar_handle->ah_flags &= ~ARCHIVE_UNLINK_OLD;
+ tar_handle->ah_flags |= ARCHIVE_O_TRUNC;
+ }
+
if (opt & OPT_GZIP)
get_header_ptr = get_header_tar_gz;
diff --git a/include/unarchive.h b/include/unarchive.h
index 35ce521..68e83f0 100644
--- a/include/unarchive.h
+++ b/include/unarchive.h
@@ -58,7 +58,7 @@ typedef struct archive_handle_t {
char *ah_buffer;
/* Flags and misc. stuff */
- unsigned char ah_flags;
+ unsigned ah_flags;
/* "Private" storage for archivers */
// unsigned char ah_priv_inited;
@@ -74,6 +74,7 @@ typedef struct archive_handle_t {
#define ARCHIVE_DONT_RESTORE_OWNER (1 << 5)
#define ARCHIVE_DONT_RESTORE_PERM (1 << 6)
#define ARCHIVE_NUMERIC_OWNER (1 << 7)
+#define ARCHIVE_O_TRUNC (1 << 8)
/* Info struct unpackers can fill out to inform users of thing like
diff --git a/testsuite/tar.tests b/testsuite/tar.tests
index 35f96b7..6c136a6 100755
--- a/testsuite/tar.tests
+++ b/testsuite/tar.tests
@@ -31,6 +31,19 @@ Ok
" \
"" ""
+testing "tar --overwrite" "\
+rm -rf input_* test.tar 2>/dev/null
+ln input input_hard
+tar cf test.tar input_hard
+echo WRONG >input
+# --overwrite opens 'input_hard' without unlinking,
+# thus 'input_hard' still linked to 'input' and we write 'Ok' into it
+tar xf test.tar --overwrite 2>&1 && cat input
+" "\
+Ok
+" \
+"Ok\n" ""
+
cd .. && rm -rf tempdir || exit 1
exit $FAILCOUNT