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To avoid operating on files whose names match a particular pattern, use the --exclude or --exclude-from options.
Causes tar
to ignore files that match the pattern.
The --exclude=pattern option prevents any file or member whose name matches the shell wildcard (pattern) from being operated on. For example, to create an archive with all the contents of the directory src except for files whose names end in .o, use the command ‘tar -cf src.tar --exclude='*.o' src’.
You may give multiple --exclude options.
Causes tar
to ignore files that match the patterns listed in
file.
Use the --exclude-from option to read a
list of patterns, one per line, from file; tar
will
ignore files matching those patterns. Thus if tar
is
called as ‘tar -c -X foo .’ and the file foo contains a
single line *.o, no files whose names end in .o will be
added to the archive.
Notice, that lines from file are read verbatim. One of the frequent errors is leaving some extra whitespace after a file name, which is difficult to catch using text editors.
However, empty lines are OK.
When archiving directories that are under some version control system (VCS), it is often convenient to read exclusion patterns from this VCS’ ignore files (e.g. .cvsignore, .gitignore, etc.) The following options provide such possibility:
Before archiving a directory, see if it contains any of the following files: cvsignore, .gitignore, .bzrignore, or .hgignore. If so, read ignore patterns from these files.
The patterns are treated much as the corresponding VCS would treat them, i.e.:
Contains shell-style globbing patterns that apply only to the directory where this file resides. No comments are allowed in the file. Empty lines are ignored.
Contains shell-style globbing patterns. Applies to the directory where .gitfile is located and all its subdirectories.
Any line beginning with a ‘#’ is a comment. Backslash escapes the comment character.
Contains shell globbing-patterns and regular expressions (if prefixed with ‘RE:’16. Patterns affect the directory and all its subdirectories.
Any line beginning with a ‘#’ is a comment.
Contains posix regular expressions17. The line ‘syntax: glob’ switches to shell globbing patterns. The line ‘syntax: regexp’ switches back. Comments begin with a ‘#’. Patterns affect the directory and all its subdirectories.
Before dumping a directory, tar
checks if it contains
file. If so, exclusion patterns are read from this file.
The patterns affect only the directory itself.
Same as --exclude-ignore, except that the patterns read affect both the directory where file resides and all its subdirectories.
Exclude files and directories used by following version control systems: ‘CVS’, ‘RCS’, ‘SCCS’, ‘SVN’, ‘Arch’, ‘Bazaar’, ‘Mercurial’, and ‘Darcs’.
As of version 1.34, the following files are excluded:
Exclude backup and lock files. This option causes exclusion of files that match the following shell globbing patterns:
When creating an archive, the --exclude-caches option family
causes tar
to exclude all directories that contain a cache
directory tag. A cache directory tag is a short file with the
well-known name CACHEDIR.TAG and having a standard header
specified in 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.
There are three ‘exclude-caches’ options, each providing a different exclusion semantics:
Do not archive the contents of the directory, but archive the directory itself and the CACHEDIR.TAG file.
Do not archive the contents of the directory, nor the CACHEDIR.TAG file, archive only the directory itself.
Omit directories containing CACHEDIR.TAG file entirely.
Another option family, --exclude-tag, provides a generalization of this concept. It takes a single argument, a file name to look for. Any directory that contains this file will be excluded from the dump. Similarly to ‘exclude-caches’, there are three options in this option family:
Do not dump the contents of the directory, but dump the directory itself and the file.
Do not dump the contents of the directory, nor the file, archive only the directory itself.
Omit directories containing file file entirely.
Multiple --exclude-tag* options can be given.
For example, given this directory:
$ find dir dir dir/blues dir/jazz dir/folk dir/folk/tagfile dir/folk/sanjuan dir/folk/trote
The --exclude-tag will produce the following:
$ tar -cf archive.tar --exclude-tag=tagfile -v dir dir/ dir/blues dir/jazz dir/folk/ tar: dir/folk/: contains a cache directory tag tagfile; contents not dumped dir/folk/tagfile
Both the dir/folk directory and its tagfile are preserved in the archive, however the rest of files in this directory are not.
Now, using the --exclude-tag-under option will exclude tagfile from the dump, while still preserving the directory itself, as shown in this example:
$ tar -cf archive.tar --exclude-tag-under=tagfile -v dir dir/ dir/blues dir/jazz dir/folk/ ./tar: dir/folk/: contains a cache directory tag tagfile; contents not dumped
Finally, using --exclude-tag-all omits the dir/folk directory entirely:
$ tar -cf archive.tar --exclude-tag-all=tagfile -v dir dir/ dir/blues dir/jazz ./tar: dir/folk/: contains a cache directory tag tagfile; directory not dumped
According to the Bazaar docs,
globbing-patterns are Korn-shell style and regular expressions are
perl-style. As of GNU tar
version 1.34, these are
treated as shell-style globs and posix extended regexps. This will be
fixed in future releases.
Support for perl-style regexps will appear in future releases.
Next: Wildcards Patterns and Matching, Previous: Reading Names from a File, Up: Choosing Files and Names for tar
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