@var{regexp} and @var{replace} are described in detail in
@ref{The "s" Command, The "s" Command, The `s' Command, sed, GNU sed}.
-The supported @var{flags} are:
+Supported @var{flags} are:
@table @samp
@item g
@var{regexp} is an @dfn{extended regular expression} (@pxref{Extended
regexps, Extended regular expressions, Extended regular expressions,
sed, GNU sed}.
+
+@item @var{number}
+Only replace the @var{number}th match of the @var{regexp}.
+
+Note: the @var{posix} standard does not specify what should happen
+when you mix the @samp{g} and @var{number} modifiers. @GNUTAR{}
+follows the GNU @command{sed} implementation in this regard, so
+the the interaction is defined to be: ignore matches before the
+@var{number}th, and then match and replace all matches from the
+@var{number}th on.
+
@end table
Any delimiter can be used in lieue of @samp{/}, the only requirement being
@item Extract @file{usr/} hierarchy into @file{usr/local/}:
@smallexample
-$ @kbd{tar --transform='s,usr/,usr/local/,' -x arch.tar}
+$ @kbd{tar --transform='s,usr/,usr/local/,' -x -f arch.tar}
@end smallexample
@item Strip two leading directory components (equivalent to
@option{--strip-components=2}):
@smallexample
-$ @kbd{tar --transform='s,/*[^/]*/[^/]*/,,' -x arch.tar}
+$ @kbd{tar --transform='s,/*[^/]*/[^/]*/,,' -x -f arch.tar}
@end smallexample
@item Prepend @file{/prefix/} to each file name:
@smallexample
-$ @kbd{tar --transform 's,^,/prefix/,' -x arch.tar}
+$ @kbd{tar --transform 's,^,/prefix/,' -x -f arch.tar}
@end smallexample
@item Convert each file name to lower case:
@smallexample
-$ @kbd{tar --transform 's/.*/\L&/' -x arch.tar}
+$ @kbd{tar --transform 's/.*/\L&/' -x -f arch.tar}
@end smallexample
@end enumerate
$ @kbd{tar -cf arch.tar --transform='s,^usr/,var/,' \
--verbose --show-transformed-names /}
@end smallexample
+
+If both @option{--strip-components} and @option{--transform} are used
+together, then @option{--transform} is applied first, and the required
+number of components is then stripped from its result.
@node after
@section Operating Only on New Files