From 06742ec624c4be64ea1033f5470b668162c022cb Mon Sep 17 00:00:00 2001 From: Sergey Poznyakoff Date: Mon, 4 Oct 2004 09:27:13 +0000 Subject: [PATCH] New function check_cache_directory(), called from dump_dir0() if exclude_caches_option is set, to check for a cache directory tag and exclude the directory if such a tag is found. --- src/create.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 51 insertions(+) diff --git a/src/create.c b/src/create.c index d583e7f..4cd5980 100644 --- a/src/create.c +++ b/src/create.c @@ -922,6 +922,47 @@ dump_regular_finish (int fd, struct tar_stat_info *st, time_t original_ctime) } } +/* Look in directory DIRNAME for a cache directory tag file + with the magic name "CACHEDIR.TAG" and a standard header, + as described at: + http://www.brynosaurus.com/cachedir + Applications can write this file into directories they create + for use as caches containing purely regenerable, non-precious data, + allowing us to avoid archiving them if --exclude-caches is specified. */ + +#define CACHEDIR_SIGNATURE "Signature: 8a477f597d28d172789f06886806bc55" +#define CACHEDIR_SIGNATURE_SIZE (sizeof CACHEDIR_SIGNATURE - 1) + +static bool +check_cache_directory (char *dirname) +{ + static char tagname[] = "CACHEDIR.TAG"; + char *tagpath; + int fd; + int tag_present = false; + + tagpath = xmalloc (strlen (dirname) + strlen (tagname) + 1); + strcpy (tagpath, dirname); + strcat (tagpath, tagname); + + fd = open (tagpath, O_RDONLY); + if (fd >= 0) + { + static char tagbuf[CACHEDIR_SIGNATURE_SIZE]; + + if (read (fd, tagbuf, CACHEDIR_SIGNATURE_SIZE) + == CACHEDIR_SIGNATURE_SIZE + && memcmp (tagbuf, CACHEDIR_SIGNATURE, CACHEDIR_SIGNATURE_SIZE) == 0) + tag_present = true; + + close (fd); + } + + free (tagpath); + + return tag_present; +} + static void dump_dir0 (char *directory, struct tar_stat_info *st, int top_level, dev_t parent_device) @@ -1012,6 +1053,16 @@ dump_dir0 (char *directory, return; } + if (exclude_caches_option + && check_cache_directory(st->orig_file_name)) + { + if (verbose_option) + WARN ((0, 0, + _("%s: contains a cache directory tag; not dumped"), + quotearg_colon (st->orig_file_name))); + return; + } + { char const *entry; size_t entry_len; -- 2.44.0