diff options
Diffstat (limited to 'doc/tar.texi')
| -rw-r--r-- | doc/tar.texi | 64 |
1 files changed, 60 insertions, 4 deletions
diff --git a/doc/tar.texi b/doc/tar.texi index f86f077a..43970adf 100644 --- a/doc/tar.texi +++ b/doc/tar.texi @@ -2905,6 +2905,13 @@ characters set by the previous @option{--quote-chars} option With this option, @command{tar} will not recurse into directories. @xref{recurse}. +@opsummary{no-transform-symlinks} +@item --no-transform-symlinks +Cancel the effect of any prior @command{--transform-symlinks} option +(see below) and return to the default behavior of applying name +transformation expression only to the names of files (archive +members), not to target of symbolic links. + @opsummary{no-same-owner} @item --no-same-owner @itemx -o @@ -3266,8 +3273,9 @@ rather than the data modification time stored in the archive. @xref{Data Modification Times}. @opsummary{transform} +@opsummary{xform} @item --transform=@var{sed-expr} - +@itemx --xform=@var{sed-expr} Transform file or member names using @command{sed} replacement expression @var{sed-expr}. For example, @@ -3284,6 +3292,11 @@ To see transformed member names in verbose listings, use @option{--show-transformed-names} option (@pxref{show-transformed-names}). +@opsummary{transform-symlinks} +@item --transform-symlinks +Apply @command{--transform} option to symbolic link targets +(@pxref{transform}). + @opsummary{uncompress} @item --uncompress @@ -7553,7 +7566,7 @@ characters that are quoted by default in the selected quoting style. @command{Tar} archives contain detailed information about files stored in them and full file names are part of that information. When -storing file to an archive, its file name is recorded in the archive +storing file to an archive, its file name is recorded in it, along with the actual file contents. When restoring from an archive, a file is created on disk with exactly the same name as that stored in the archive. In the majority of cases this is the desired behavior @@ -7570,7 +7583,7 @@ directory components, or with otherwise modified names. In other cases it is desirable to store files under differing names in the archive. -@GNUTAR{} provides two options for these needs. +@GNUTAR{} provides several options for these needs. @table @option @opindex strip-components @@ -7644,7 +7657,9 @@ In case you need to apply more complex modifications to the file name, @table @option @opindex transform +@opindex xform @item --transform=@var{expression} +@itemx --xform=@var{expression} Modify file names using supplied @var{expression}. @end table @@ -7683,7 +7698,7 @@ 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 +Note: the @acronym{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 interaction is defined to be: ignore matches before the @@ -7737,6 +7752,47 @@ $ @kbd{tar --transform 's/.*/\L&/' -x -f arch.tar} @end enumerate +The @option{--transform} option applies only to member names. It does +not apply to symbolic link targets. In many cases, this is the +desired behavior. Consider for example, archiving the @file{/lib} +directory: + +@smallexample +$ @kbd{tar -vv -c -f archive /lib} +tar: Removing leading `/' from member names +drwxr-xr-x root/root 0 2008-07-08 16:20 /lib/ +-rwxr-xr-x root/root 1250840 2008-05-25 07:44 /lib/libc-2.3.2.so +lrwxrwxrwx root/root 0 2008-06-24 17:12 /lib/libc.so.6 -> libc-2.3.2.so +... +@end smallexample + +Now, you can use our example above to extract it into @file{/usr/local}: + +@smallexample +$ @kbd{tar --transform 's,^,/usr/local/,' \ + --show-transformed -v -x -f archive} +drwxr-xr-x root/root 0 2008-07-08 16:20 /usr/local/lib/ +-rwxr-xr-x root/root 1250840 2008-05-25 07:44 /usr/local/lib/libc-2.3.2.so +lrwxrwxrwx root/root 0 2008-06-24 17:12 /usr/local/lib/libc.so.6 -> +libc-2.3.2.so +@end smallexample + +As you see, it correctly extracts @file{libc.so.6} as a symbolic link +to @file{libc-2.3.2.so}. + +However, sometimes you may need to transform symbolic link targets as +well. To do so, @GNUTAR provides an additional option: + +@table @option +@opindex transform-symlinks +@item --transform-symlinks +Apply @command{--transform} option to symbolic link targets. + +@opindex no-transform-symlinks +@itemx --no-transform-symlinks +Cancel the effect of the previous @option{--transform-symlinks} option. +@end table + Unlike @option{--strip-components}, @option{--transform} can be used in any @GNUTAR{} operation mode. For example, the following command adds files to the archive while replacing the leading @file{usr/} |