Appendix A Changes

This appendix lists some important user-visible changes between version GNU tar 1.15.90 and previous versions. An up-to-date version of this document is available at the GNU tar documentation page.

Use of short option -o.

Earlier versions of GNU tar understood -o command line option as a synonym for --old-archive.

GNU tar starting from version 1.13.90 understands this option as a synonym for --no-same-owner. This is compatible with UNIX98 tar implementations.

However, to facilitate transition, -o option retains its old semantics when it is used with one of archive-creation commands. Users are encouraged to use --format=oldgnu instead.

It is especially important, since versions of GNU Automake up to and including 1.8.4 invoke tar with this option to produce distribution tarballs. See v7, for the detailed discussion of this issue and its implications.

Future versions of GNU tar will understand -o only as a synonym for --no-same-owner.

Use of short option -l

Earlier versions of GNU tar understood -l option as a synonym for --one-file-system. Such usage is deprecated. For compatibility with other implementations future versions of GNU tar will understand this option as a synonym for --check-links.

Use of options --portability and --old-archive

These options are deprecated. Please use --format=v7 instead.

Use of option --posix

This option is deprecated. Please use --format=posix instead.