Index: ChangeLog =================================================================== RCS file: /cvsroot/tar/tar/ChangeLog,v retrieving revision 1.119 diff -u -r1.119 ChangeLog --- ChangeLog 19 Aug 2004 13:13:37 -0000 1.119 +++ ChangeLog 20 Aug 2004 10:22:35 -0000 @@ -1,3 +1,17 @@ +2004-08-20 Bryan Ford + + * src/tar.c: New option --exclude-caches, to exclude + cache directories automatically on archive creation. + Cache directories are directories containing a + standardized tag file, as specified at: + http://www.brynosaurus.com/cachedir/spec.html + * src/common.h: New variable exclude_caches_option. + * src/create.c: 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. + * doc/tar.texi: Updated accordingly. + 2004-08-19 Sergey Poznyakoff * scripts/backup.in: Renamed LIBPATH to LIBDIR. Index: doc/tar.texi =================================================================== RCS file: /cvsroot/tar/tar/doc/tar.texi,v retrieving revision 1.58 diff -u -r1.58 tar.texi --- doc/tar.texi 19 Aug 2004 13:10:01 -0000 1.58 +++ doc/tar.texi 20 Aug 2004 10:23:03 -0000 @@ -201,6 +201,11 @@ @set xref-exclude-from @xref{exclude} @set pxref-exclude-from @pxref{exclude} +@set op-exclude-caches @kbd{--exclude-caches} +@set ref-exclude-from @ref{exclude-caches} +@set xref-exclude-from @xref{exclude-caches} +@set pxref-exclude-from @pxref{exclude-caches} + @set op-extract @kbd{--extract} (@kbd{--get}, @kbd{-x}) @set ref-extract @ref{extract} @set xref-extract @xref{extract} @@ -2743,6 +2748,11 @@ Similar to @samp{--exclude}, except @command{tar} will use the list of patterns in the file @var{file}. @FIXME-xref{} +@item --exclude-caches + +Automatically excludes all directories +containing a cache directory tag. @FIXME-xref{} + @item --file=@var{archive} @itemx -f @var{archive} @@ -6144,6 +6154,24 @@ @FIXME{do the exclude options files need to have stuff separated by newlines the same as the files-from option does?} +@table @kbd +@item --exclude-caches +Causes @command{tar} to ignore directories containing a cache directory tag. +@end table + +@findex exclude-caches +When creating an archive, +the @samp{--exclude-caches} option +causes @command{tar} to exclude all directories +that contain a @dfn{cache directory tag}. +A cache directory tag is a short file +with the well-known name @file{CACHEDIR.TAG} +and having a standard header +specified in @url{http://www.brynosaurus.com/cachedir/spec.html}. +Various applications write cache directory tags +into directories they use to hold regenerable, non-precious data, +so that such data can be more easily excluded from backups. + @menu * controlling pattern-patching with exclude:: * problems with exclude:: Index: src/common.h =================================================================== RCS file: /cvsroot/tar/tar/src/common.h,v retrieving revision 1.38 diff -u -r1.38 common.h --- src/common.h 3 Aug 2004 04:44:39 -0000 1.38 +++ src/common.h 20 Aug 2004 10:23:05 -0000 @@ -160,6 +160,9 @@ /* Patterns that match file names to be excluded. */ GLOBAL struct exclude *excluded; +/* Exclude directories containing a cache directory tag. */ +GLOBAL bool exclude_caches_option; + /* Specified file containing names to work on. */ GLOBAL const char *files_from_option; Index: src/create.c =================================================================== RCS file: /cvsroot/tar/tar/src/create.c,v retrieving revision 1.86 diff -u -r1.86 create.c --- src/create.c 8 Aug 2004 14:20:17 -0000 1.86 +++ src/create.c 20 Aug 2004 10:23:08 -0000 @@ -922,6 +922,45 @@ } } +/* 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. */ +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 taghdr[] = "Signature: 8a477f597d28d172789f06886806bc55"; + static char tagbuf[43]; + + if (read(fd, tagbuf, 43) == 43) + { + if (memcmp(taghdr, tagbuf, 43) == 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 +1051,16 @@ 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; Index: src/tar.c =================================================================== RCS file: /cvsroot/tar/tar/src/tar.c,v retrieving revision 1.95 diff -u -r1.95 tar.c --- src/tar.c 17 Aug 2004 16:05:03 -0000 1.95 +++ src/tar.c 20 Aug 2004 10:23:11 -0000 @@ -186,6 +186,7 @@ CHECK_LINKS_OPTION, DELETE_OPTION, EXCLUDE_OPTION, + EXCLUDE_CACHES_OPTION, FORCE_LOCAL_OPTION, GROUP_OPTION, IGNORE_CASE_OPTION, @@ -445,6 +446,8 @@ N_("exclude files, given as a PATTERN"), 71 }, {"exclude-from", 'X', N_("FILE"), 0, N_("exclude patterns listed in FILE"), 71 }, + {"exclude-caches", EXCLUDE_CACHES_OPTION, 0, 0, + N_("exclude directories containing a cache tag"), 71 }, {"ignore-case", IGNORE_CASE_OPTION, 0, 0, N_("exclusion ignores case"), 71 }, {"anchored", ANCHORED_OPTION, 0, 0, @@ -914,6 +917,10 @@ add_exclude (excluded, arg, args->exclude_options | recursion_option); break; + case EXCLUDE_CACHES_OPTION: + exclude_caches_option = true; + break; + case FORCE_LOCAL_OPTION: force_local_option = true; break;