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(tar.info)Wildcards

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Wildcards Patterns and Matching
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   "Globbing" is the operation by which "wildcard" characters, `*' or
`?' for example, are replaced and expanded into all existing files
matching the given pattern.  However, `tar' often uses wildcard
patterns for matching (or globbing) archive members instead of actual
files in the filesystem.  Wildcard patterns are also used for verifying
volume labels of `tar' archives.  This section has the purpose of
explaining wildcard syntax for `tar'.

   A PATTERN should be written according to shell syntax, using wildcard
characters to effect globbing.  Most characters in the pattern stand
for themselves in the matched string, and case is significant: `a' will
match only `a', and not `A'.  The character `?' in the pattern matches
any single character in the matched string.  The character `*' in the
pattern matches zero, one, or more single characters in the matched
string.  The character `\' says to take the following character of the
pattern _literally_; it is useful when one needs to match the `?', `*',
`[' or `\' characters, themselves.

   The character `[', up to the matching `]', introduces a character
class.  A "character class" is a list of acceptable characters for the
next single character of the matched string.  For example, `[abcde]'
would match any of the first five letters of the alphabet.  Note that
within a character class, all of the "special characters" listed above
other than `\' lose their special meaning; for example, `[-\\[*?]]'
would match any of the characters, `-', `\', `[', `*', `?', or `]'.
(Due to parsing constraints, the characters `-' and `]' must either
come _first_ or _last_ in a character class.)

   If the first character of the class after the opening `[' is `!' or
`^', then the meaning of the class is reversed.  Rather than listing
character to match, it lists those characters which are _forbidden_ as
the next single character of the matched string.

   Other characters of the class stand for themselves.  The special
construction `[A-E]', using an hyphen between two letters, is meant to
represent all characters between A and E, inclusive.

   Periods (`.') or forward slashes (`/') are not considered special
for wildcard matches.  However, if a pattern completely matches a
directory prefix of a matched string, then it matches the full matched
string: excluding a directory also excludes all the files beneath it.

   There are some discussions floating in the air and asking for
modifications in the way GNU `tar' accomplishes wildcard matches.  We
perceive any change of semantics in this area as a delicate thing to
impose on GNU `tar' users.  On the other hand, the GNU project should be
progressive enough to correct any ill design: compatibility at all price
is not always a good attitude.  In conclusion, it is _possible_ that
slight amendments be later brought to the previous description.  Your
opinions on the matter are welcome.