- This article is about the archive format. For the image format, see PAX (Pick Ax).
pax format (Portable Archive eXchange), or pax interchange format, is an extension of the tar archive format to support arbitrary named attributes. It may also be referred to as something like POSIX.1-2001 tar format.
pax is also the name of a multi-format archiver utility for Unix-like systems. Different editions of pax support different sets of formats. Formats that pax may support include tar, cpio, AR, bar, and ZIP. Some editions of pax support pax format, but some ironically don't.
- Open Group Base Specifications Issue 7 / IEEE Std 1003.1, 2013 Edition: pax command & interchange format
- Format of pax archives
See also Tape Archive#Specifications.