1.1 What is Bash?
Bash is the shell, or command language interpreter,
for the GNU operating system.
The name is an acronym for the 'Bourne-Again SHell',
a pun on Stephen Bourne, the author of the direct ancestor of
the current Unix shell
which appeared in the Seventh Edition Bell Labs Research version
Bash is largely compatible with
sh and incorporates useful
features from the Korn shell
ksh and the C shell
It is intended to be a conformant implementation of the IEEE
POSIX Shell and Tools specification (IEEE Working Group 1003.2).
It offers functional improvements over
sh for both interactive and
While the GNU operating system provides other shells, including
a version of
csh, Bash is the default shell.
Like other GNU software, Bash is quite portable. It currently runs
on nearly every version of Unix and a few other operating systems -
independently-supported ports exist for MS-DOS, OS/2,
Windows 95/98, and Windows NT.