From 8a936cfab718aee9f304f1b41e6b16cf6b5999f9 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Wed, 16 Dec 2009 23:18:59 +0100 Subject: [PATCH] tar: add support for --overwrite. +70 bytes. Signed-off-by: Denys Vlasenko --- archival/libunarchive/data_extract_all.c | 5 ++++- archival/tar.c | 13 +++++++++++-- include/unarchive.h | 3 ++- testsuite/tar.tests | 13 +++++++++++++ 4 files changed, 30 insertions(+), 4 deletions(-) diff --git a/archival/libunarchive/data_extract_all.c b/archival/libunarchive/data_extract_all.c index ae242df64..874d37d94 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 7ec101d31..5994d8913 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 35ce52181..68e83f01c 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 35f96b77e..6c136a615 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