[git commit master 1/1] tar: optional support for --to-command
Denys Vlasenko
vda.linux at googlemail.com
Thu Jun 24 23:33:00 UTC 2010
commit: http://git.busybox.net/busybox/commit/?id=2b46fd49b14b2ac30e0c767c65ac2b29f6922a45
branch: http://git.busybox.net/busybox/commit/?id=refs/heads/master
function old new delta
data_extract_to_command - 430 +430
dec2env - 44 +44
tar_main 778 819 +41
str2env - 37 +37
tar_var - 32 +32
xputenv - 22 +22
tar_longopts 257 270 +13
------------------------------------------------------------------------------
(add/remove: 6/0 grow/shrink: 2/0 up/down: 619/0) Total: 619 bytes
Signed-off-by: Ladislav Michl <Ladislav.Michl at seznam.cz>
Signed-off-by: Denys Vlasenko <vda.linux at googlemail.com>
---
archival/Config.src | 9 ++
archival/libunarchive/Kbuild.src | 1 +
archival/libunarchive/data_extract_to_command.c | 137 +++++++++++++++++++++++
archival/tar.c | 12 ++
include/unarchive.h | 4 +
5 files changed, 163 insertions(+), 0 deletions(-)
create mode 100644 archival/libunarchive/data_extract_to_command.c
diff --git a/archival/Config.src b/archival/Config.src
index 3dbd3ae..f64b334 100644
--- a/archival/Config.src
+++ b/archival/Config.src
@@ -280,6 +280,15 @@ config FEATURE_TAR_LONG_OPTIONS
help
Enable use of long options, increases size by about 400 Bytes
+config FEATURE_TAR_TO_COMMAND
+ bool "Support for writing to an external program"
+ default y
+ depends on TAR && FEATURE_TAR_LONG_OPTIONS
+ help
+ If you enable this option you'll be able to instruct tar to send
+ the contents of each extracted file to the standard input of an
+ external program.
+
config FEATURE_TAR_UNAME_GNAME
bool "Enable use of user and group names"
default y
diff --git a/archival/libunarchive/Kbuild.src b/archival/libunarchive/Kbuild.src
index 8185455..6ad1d7a 100644
--- a/archival/libunarchive/Kbuild.src
+++ b/archival/libunarchive/Kbuild.src
@@ -53,6 +53,7 @@ lib-$(CONFIG_FEATURE_SEAMLESS_BZ2) += open_transformer.o decompress_bunzip2
lib-$(CONFIG_FEATURE_SEAMLESS_LZMA) += open_transformer.o decompress_unlzma.o get_header_tar_lzma.o
lib-$(CONFIG_FEATURE_SEAMLESS_XZ) += open_transformer.o decompress_unxz.o
lib-$(CONFIG_FEATURE_COMPRESS_USAGE) += decompress_bunzip2.o
+lib-$(CONFIG_FEATURE_TAR_TO_COMMAND) += data_extract_to_command.o
ifneq ($(lib-y),)
lib-y += $(COMMON_FILES)
diff --git a/archival/libunarchive/data_extract_to_command.c b/archival/libunarchive/data_extract_to_command.c
new file mode 100644
index 0000000..983c530
--- /dev/null
+++ b/archival/libunarchive/data_extract_to_command.c
@@ -0,0 +1,137 @@
+/* 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"
+
+enum {
+ //TAR_FILETYPE,
+ TAR_MODE,
+ TAR_FILENAME,
+ TAR_REALNAME,
+#if ENABLE_FEATURE_TAR_UNAME_GNAME
+ TAR_UNAME,
+ TAR_GNAME,
+#endif
+ TAR_SIZE,
+ TAR_UID,
+ TAR_GID,
+ TAR_MAX,
+};
+
+static const char *const tar_var[] = {
+ // "FILETYPE",
+ "MODE",
+ "FILENAME",
+ "REALNAME",
+#if ENABLE_FEATURE_TAR_UNAME_GNAME
+ "UNAME",
+ "GNAME",
+#endif
+ "SIZE",
+ "UID",
+ "GID",
+};
+
+static void xputenv(char *str)
+{
+ if (putenv(str))
+ bb_error_msg_and_die(bb_msg_memory_exhausted);
+}
+
+static void str2env(char *env[], int idx, const char *str)
+{
+ env[idx] = xasprintf("TAR_%s=%s", tar_var[idx], str);
+ xputenv(env[idx]);
+}
+
+static void dec2env(char *env[], int idx, unsigned long long val)
+{
+ env[idx] = xasprintf("TAR_%s=%llu", tar_var[idx], val);
+ xputenv(env[idx]);
+}
+
+static void oct2env(char *env[], int idx, unsigned long val)
+{
+ env[idx] = xasprintf("TAR_%s=%lo", tar_var[idx], val);
+ xputenv(env[idx]);
+}
+
+void FAST_FUNC data_extract_to_command(archive_handle_t *archive_handle)
+{
+ file_header_t *file_header = archive_handle->file_header;
+
+#if 0 /* do we need this? ENABLE_FEATURE_TAR_SELINUX */
+ char *sctx = archive_handle->tar__next_file_sctx;
+ if (!sctx)
+ sctx = archive_handle->tar__global_sctx;
+ if (sctx) { /* setfscreatecon is 4 syscalls, avoid if possible */
+ setfscreatecon(sctx);
+ free(archive_handle->tar__next_file_sctx);
+ archive_handle->tar__next_file_sctx = NULL;
+ }
+#endif
+
+ if ((file_header->mode & S_IFMT) == S_IFREG) {
+ pid_t pid;
+ int p[2], status;
+ char *tar_env[TAR_MAX];
+
+ memset(tar_env, 0, sizeof(tar_env));
+
+ xpipe(p);
+ pid = BB_MMU ? fork() : vfork();
+ switch (pid) {
+ case -1:
+ bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
+ case 0:
+ /* Child */
+ /* str2env(tar_env, TAR_FILETYPE, "f"); - parent should do it once */
+ oct2env(tar_env, TAR_MODE, file_header->mode);
+ str2env(tar_env, TAR_FILENAME, file_header->name);
+ str2env(tar_env, TAR_REALNAME, file_header->name);
+#if ENABLE_FEATURE_TAR_UNAME_GNAME
+ str2env(tar_env, TAR_UNAME, file_header->tar__uname);
+ str2env(tar_env, TAR_GNAME, file_header->tar__gname);
+#endif
+ dec2env(tar_env, TAR_SIZE, file_header->size);
+ dec2env(tar_env, TAR_UID, file_header->uid);
+ dec2env(tar_env, TAR_GID, file_header->gid);
+ close(p[1]);
+ xdup2(p[0], STDIN_FILENO);
+ signal(SIGPIPE, SIG_DFL);
+ execl("/bin/sh", "/bin/sh" + 5, "-c", archive_handle->tar__to_command, NULL);
+ bb_perror_msg_and_die("can't execute '%s'", "/bin/sh");
+ }
+ close(p[0]);
+ /* Our caller is expected to do signal(SIGPIPE, SIG_IGN)
+ * so that we don't die if child don't read all the input: */
+ bb_copyfd_exact_size(archive_handle->src_fd, p[1], file_header->size);
+ close(p[1]);
+
+ if (safe_waitpid(pid, &status, 0) == -1)
+ bb_perror_msg_and_die("waitpid");
+ if (WIFEXITED(status) && WEXITSTATUS(status))
+ bb_error_msg_and_die("'%s' returned status %d",
+ archive_handle->tar__to_command, WEXITSTATUS(status));
+ if (WIFSIGNALED(status))
+ bb_error_msg_and_die("'%s' terminated on signal %d",
+ archive_handle->tar__to_command, WTERMSIG(status));
+
+ if (!BB_MMU) {
+ int i;
+ for (i = 0; i < TAR_MAX; i++) {
+ if (tar_env[i])
+ bb_unsetenv_and_free(tar_env[i]);
+ }
+ }
+ }
+
+#if 0 /* ENABLE_FEATURE_TAR_SELINUX */
+ if (sctx)
+ /* reset the context after creating an entry */
+ setfscreatecon(NULL);
+#endif
+}
diff --git a/archival/tar.c b/archival/tar.c
index 3a94012..344c9de 100644
--- a/archival/tar.c
+++ b/archival/tar.c
@@ -750,6 +750,7 @@ enum {
IF_FEATURE_SEAMLESS_Z( OPTBIT_COMPRESS ,) // 16th bit
IF_FEATURE_TAR_NOPRESERVE_TIME(OPTBIT_NOPRESERVE_TIME,)
#if ENABLE_FEATURE_TAR_LONG_OPTIONS
+ IF_FEATURE_TAR_TO_COMMAND(OPTBIT_2COMMAND ,)
OPTBIT_NUMERIC_OWNER,
OPTBIT_NOPRESERVE_PERM,
OPTBIT_OVERWRITE,
@@ -772,6 +773,7 @@ enum {
OPT_GZIP = IF_FEATURE_SEAMLESS_GZ( (1 << OPTBIT_GZIP )) + 0, // z
OPT_COMPRESS = IF_FEATURE_SEAMLESS_Z( (1 << OPTBIT_COMPRESS )) + 0, // Z
OPT_NOPRESERVE_TIME = IF_FEATURE_TAR_NOPRESERVE_TIME((1 << OPTBIT_NOPRESERVE_TIME)) + 0, // m
+ OPT_2COMMAND = IF_FEATURE_TAR_TO_COMMAND( (1 << OPTBIT_2COMMAND )) + 0, // to-command
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
@@ -813,6 +815,9 @@ static const char tar_longopts[] ALIGN1 =
# if ENABLE_FEATURE_TAR_NOPRESERVE_TIME
"touch\0" No_argument "m"
# endif
+# if ENABLE_FEATURE_TAR_TO_COMMAND
+ "to-command\0" Required_argument "\xfb"
+# endif
/* use numeric uid/gid from tar header, not textual */
"numeric-owner\0" No_argument "\xfc"
/* do not restore mode */
@@ -904,6 +909,7 @@ int tar_main(int argc UNUSED_PARAM, char **argv)
, &tar_filename // -f filename
IF_FEATURE_TAR_FROM(, &(tar_handle->accept)) // T
IF_FEATURE_TAR_FROM(, &(tar_handle->reject)) // X
+ IF_FEATURE_TAR_TO_COMMAND(, &(tar_handle->tar__to_command)) // --to-command
#if ENABLE_FEATURE_TAR_LONG_OPTIONS && ENABLE_FEATURE_TAR_FROM
, &excludes // --exclude
#endif
@@ -922,6 +928,12 @@ int tar_main(int argc UNUSED_PARAM, char **argv)
if (opt & OPT_2STDOUT)
tar_handle->action_data = data_extract_to_stdout;
+ if (opt & OPT_2COMMAND) {
+ putenv((char*)"TAR_FILETYPE=f");
+ signal(SIGPIPE, SIG_IGN);
+ tar_handle->action_data = data_extract_to_command;
+ }
+
if (opt & OPT_KEEP_OLD)
tar_handle->ah_flags &= ~ARCHIVE_UNLINK_OLD;
diff --git a/include/unarchive.h b/include/unarchive.h
index 8009de2..f3aa05d 100644
--- a/include/unarchive.h
+++ b/include/unarchive.h
@@ -75,6 +75,9 @@ typedef struct archive_handle_t {
char* tar__longname;
char* tar__linkname;
# endif
+#if ENABLE_FEATURE_TAR_TO_COMMAND
+ char* tar__to_command;
+#endif
# if ENABLE_FEATURE_TAR_SELINUX
char* tar__global_sctx;
char* tar__next_file_sctx;
@@ -128,6 +131,7 @@ extern void unpack_ar_archive(archive_handle_t *ar_archive) FAST_FUNC;
extern void data_skip(archive_handle_t *archive_handle) FAST_FUNC;
extern void data_extract_all(archive_handle_t *archive_handle) FAST_FUNC;
extern void data_extract_to_stdout(archive_handle_t *archive_handle) FAST_FUNC;
+extern void data_extract_to_command(archive_handle_t *archive_handle) FAST_FUNC;
extern void header_skip(const file_header_t *file_header) FAST_FUNC;
extern void header_list(const file_header_t *file_header) FAST_FUNC;
--
1.7.1
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