man cpio
...
STANDARDS
There is no current POSIX standard for the cpio command; it appeared in
ISO/IEC 9945-1:1996 (“POSIX.1”) but was dropped from IEEE Std 1003.1-2001
(“POSIX.1”). The cpio, ustar, and pax interchange file formats are defined by IEEE Std
1003.1-2001 (“POSIX.1”) for the pax command.
HISTORY
The original cpio and find utilities were written by Dick Haight while
working in AT&T's Unix Support Group. They first appeared in 1977 in
PWB/UNIX 1.0, the “Programmer's Work Bench” system developed for use
within AT&T. They were first released outside of AT&T as part of System
III Unix in 1981. As a result, cpio actually predates tar, even though
it was not well-known outside of AT&T until some time later.
This is a complete re-implementation based on the libarchive(3) library.
BUGS
The cpio archive format has several basic limitations: It does not store
user and group names, only numbers. As a result, it cannot be reliably
used to transfer files between systems with dissimilar user and group
numbering. Older cpio formats limit the user and group numbers to 16 or
18 bits, which is insufficient for modern systems. The cpio archive for‐
mats cannot support files over 4 gigabytes, except for the “odc” variant,
which can support files up to 8 gigabytes.
FreeBSD 8.0 December 21, 2007 FreeBSD 8.0
man pax
...
STANDARDS
The pax utility is a superset of the IEEE Std 1003.2 (“POSIX.2”) stan‐
dard. The options -z, -B, -D, -E, -G, -H, -L, -P, -T, -U, -Y, -Z, the
archive formats bcpio, sv4cpio, sv4crc, tar, and the flawed archive han‐
dling during list and read operations are extensions to the POSIX stan‐
dard.
HISTORY
The pax utility appeared in 4.4BSD.
AUTHORS
Keith Muller at the University of California, San Diego
BUGS
The pax utility does not recognize multibyte characters.
FreeBSD 8.0 July 3, 2004 FreeBSD 8.0
