Star

Star is a very fast tar-like tape archiver with improved functionality.

History

Star was first created in 1982 by Joerg Schilling to extract tapes on a UNIX clone that had no tar command. In 1985 the first fully functional version was release released as mtar.

Later in 1985, format extensions were introduced, and mtar was renamed to star (Schily tar.)

In 1994, Posix 1003.1-1988 extensions were added and Schily tar was renamed to it's current name, star (Standard tar.)

More information on star is provided on the star homepage

Features

Star is the fastest known implementation of a tar archiver.

It includes the first free implementation of POSIX.1-2001 extended tar headers. The POSIX.1-2001 extended tar headers define a new standard way for going beyond the limitations of the historic tar format. They allow (among other things) all UNIX time stamps to be archived withsub-second resolution, files of arbitrary size, filenames without length limitation, and file names that use UNICODE UTF-8 encoding.

Some advantages over other tar implementations include:

Built-in "find"

star is built on top of libfind and thus allows you to execute "find" like expressions in create, extract and list mode. This allows to do a lot of interesting things that could not be done if star and find would be called separatedly.

Accurate sparse files

Star is able to reproduce holes in sparse files accurately supported by the underlying OS.

Integrated pattern matcher

Star provides the ability to easily archive/extract a subset of files on a filesystem.

Sophisticated diff

Star provides an interface for comparing tar archives against existing filesystems.

No limit on filename length

Pathnames up to 1K in length are currently supported and can be increased in the future without breaking the ability to read current media

Supports all 3 POSIX timestamps

Star stores/restores all 3 POSIX timestamps of a file (including creation time.) With POSIX.1-2001 the times are in nanosecond granularity. Star may reset access time after doing backup. (On Solaris this can be done without changing the ctime.)

Automatic byte swap

Star automatically detects swapped archives and transparently reads them the right way, regardless of the endian-ness of the architecture of the system that created the archive and the architecture of the system reading the archive.

Automatic format detect

Star automatically detects several common archive formats and adopts to them. Supported archive types are: Old tar, gnu tar, ansi tar, star, POSIX.1-2001 PAX, Sun's Solaris tar, cpio.

Automatic compression detect

Star automatically detects whether the archive is compressed. If it has been compressed with a compression program that is compatible to decompression with "gzip", "bzip2", "lzop" or "p7zip", star automatically activates decompression.

Fully ansi compatible

Star is fully ANSI/Posix 1003.1 compatible. Star is the first tar implementation that supports POSIX.1-2001.

Support for ACLs and file flags

Star supports Access Control Lists and extened file flags (as found on FreeBSD and Linux). Support to archive and restore other file properties may easily added.

Support for all inode metadata

Star supports to put all inode metadata on the archive. This allows star to perform true incremental dumps.

Usage in Amanda

In Amanda Enterprise, star is provided as an alternative to GNU tar. It is used primarily for the support of extended file attributes, including POSIX ACL's and SELinux contexts.