tar: real support for -p. +200 if selected.

By Natanael Copa <natanael.copa at gmail.com>

archival/Config.in

@@ -237,7 +237,15 @@ config FEATURE_TAR_LONG_OPTIONS
 	default n
 	depends on TAR && GETOPT_LONG
 	help
-		Enable use of long options, increases size by about 400 Bytes
+	  Enable use of long options, increases size by about 400 Bytes
+
+config FEATURE_TAR_UNAME_GNAME
+	bool "Enable use of user and group names"
+	default n
+	help
+	  Enables use of user and group names in tar. This affects contents
+	  listings (-t) and preserving permissions when unpacking (-p).
+	  +200 bytes.
 
 config UNCOMPRESS
 	bool "uncompress"

archival/libunarchive/data_extract_all.c

@@ -112,7 +112,22 @@ void data_extract_all(archive_handle_t *archive_handle)
 	}
 
 	if (!(archive_handle->flags & ARCHIVE_NOPRESERVE_OWN)) {
+#if ENABLE_FEATURE_TAR_UNAME_GNAME
+		uid_t uid = file_header->uid;
+		gid_t gid = file_header->gid;
+
+		if (file_header->uname) {
+			struct passwd *pwd = getpwnam(file_header->uname);
+			if (pwd) uid = pwd->pw_uid;
+		}
+		if (file_header->gname) {
+			struct group *grp = getgrnam(file_header->gname);
+			if (grp) gid = grp->gr_gid;
+		}
+		lchown(file_header->name, uid, gid);
+#else
 		lchown(file_header->name, file_header->uid, file_header->gid);
+#endif
 	}
 	if ((file_header->mode & S_IFMT) != S_IFLNK) {
 		/* uclibc has no lchmod, glibc is even stranger -

archival/libunarchive/get_header_tar.c

@@ -187,6 +187,10 @@ char get_header_tar(archive_handle_t *archive_handle)
 		/* FIXME: what if we have non-link object with link_target? */
 		/* Will link_target be free()ed? */
 	}
+#if ENABLE_FEATURE_TAR_UNAME_GNAME
+	file_header->uname = tar.uname[0] ? xstrndup(tar.uname, sizeof(tar.uname)) : NULL;
+	file_header->gname = tar.gname[0] ? xstrndup(tar.gname, sizeof(tar.gname)) : NULL;
+#endif
 	file_header->mtime = GET_OCTAL(tar.mtime);
 	file_header->size = GET_OCTAL(tar.size);
 	file_header->gid = GET_OCTAL(tar.gid);
@@ -317,6 +321,9 @@ char get_header_tar(archive_handle_t *archive_handle)
 
 	free(file_header->link_target);
 	/* Do not free(file_header->name)! */
-
+#if ENABLE_FEATURE_TAR_UNAME_GNAME
+	free(file_header->uname);
+	free(file_header->gname);
+#endif
 	return EXIT_SUCCESS;
 }

archival/libunarchive/header_verbose_list.c

@@ -10,6 +10,33 @@ void header_verbose_list(const file_header_t *file_header)
 {
 	struct tm *mtime = localtime(&(file_header->mtime));
 
+#if ENABLE_FEATURE_TAR_UNAME_GNAME
+	char uid[8];
+	char gid[8];
+	char *user = file_header->uname;
+	char *group = file_header->gname;
+
+	if (user == NULL) {
+		snprintf(uid, sizeof(uid), "%u", (unsigned)file_header->uid);
+		user = uid;
+	}
+	if (group == NULL) {
+		snprintf(gid, sizeof(gid), "%u", (unsigned)file_header->gid);
+		group = gid;
+	}
+	printf("%s %s/%s %9u %4u-%02u-%02u %02u:%02u:%02u %s",
+		bb_mode_string(file_header->mode),
+		user,
+		group,
+		(unsigned int) file_header->size,
+		1900 + mtime->tm_year,
+		1 + mtime->tm_mon,
+		mtime->tm_mday,
+		mtime->tm_hour,
+		mtime->tm_min,
+		mtime->tm_sec,
+		file_header->name);
+#else /* !FEATURE_TAR_UNAME_GNAME */
 	printf("%s %d/%d %9"OFF_FMT"u %4u-%02u-%02u %02u:%02u:%02u %s",
 		bb_mode_string(file_header->mode),
 		file_header->uid,
@@ -22,6 +49,7 @@ void header_verbose_list(const file_header_t *file_header)
 		mtime->tm_min,
 		mtime->tm_sec,
 		file_header->name);
+#endif /* FEATURE_TAR_UNAME_GNAME */
 
 	if (file_header->link_target) {
 		printf(" -> %s", file_header->link_target);

include/unarchive.h

@@ -13,6 +13,10 @@
 typedef struct file_header_t {
 	char *name;
 	char *link_target;
+#if ENABLE_FEATURE_TAR_UNAME_GNAME
+	char *uname; 
+	char *gname;
+#endif
 	off_t size;
 	uid_t uid;
 	gid_t gid;