Xar is an open source

Open source

The term open source describes practices in production and development that promote access to the end product's source materials. Some consider open source a philosophy, others consider it a pragmatic methodology...

 file archiver

File archiver

A file archiver is a computer program that combines a number of files together into one archive file, or a series of archive files, for easier transportation or storage...

 and the archiver’s file format

File format

A file format is a particular way that information is encoded for storage in a computer file.Since a disk drive, or indeed any computer storage, can store only bits, the computer must have some way of converting information to 0s and 1s and vice-versa. There are different kinds of formats for...

. It was created within the OpenDarwin project and is used in Mac OS X 10.5 for software installation routines, as well as browser extensions in Safari 5.0. Xar replaced the use of gzip

Gzip

Gzip is any of several software applications used for file compression and decompression. The term usually refers to the GNU Project's implementation, "gzip" standing for GNU zip. It is based on the DEFLATE algorithm, which is a combination of Lempel-Ziv and Huffman coding...

ped pax files

Pax (program)

pax is an archiving utility created by POSIX and defined by the POSIX.1-2001 standard. By default, it creates archives in ustar format, also defined by the POSIX standard. Rather than sort out the incompatible options that have crept up between tar and cpio, along with their implementations across...

.

One development branch of RPM, RPM5, uses xar.

/etc/magic

The following code snippet shows the magic number

Magic number (programming)

In computer programming, the term magic number has multiple meanings. It could refer to one or more of the following:* A constant numerical or text value used to identify a file format or protocol; for files, see List of file signatures...

, in the /etc/magic format of the Unix file program:

#-------------------------------------------------------------

1. file(1) magic(5) data for xar archive file format

0 string xar! xar - eXtensible ARchiver archive
>6 beshort x - version %d

External links

• Xar homepage
• Why xar is interesting – Lists the advantages of xar.
• Diagram of the data structure of a Xar file