which is the basic differences between the shells?
keramida at ceid.upatras.gr
Sun Jun 6 11:19:32 UTC 2010
On Sat, 5 Jun 2010 22:35:09 +0000, Giorgos Tsiapaliokas <terietor at gmail.com> wrote:
> i am coming from the linux world where i was using the bash shell but
> i found out that there are also much more.
> can u tell me the basic differences between them?(pros and cons)
It isn't humanly possible to write *all* the differences of *all* the
shells in a single email reply. But you can find a good table that
compares various shells in Wikipedia:
In a FreeBSD context there are also a few more things to consider when
* Is the shell part of the base system or a port/package?
* Is the shell well maintained?
* Does the shell depend on many other ports or none at all?
* Does the shell support building static-only copies? This is useful
if you want to upgrade the base system without breaking the login
shell you are using every day.
Having said that, here are a few personal notes from my own experience
with shells on FreeBSD...
The /bin/sh and /bin/csh shells are part of the base system, so they are
rebuilt as part of the normal buildworld process. The big advantage of
using a shell that is part of the base system is that it's always
there. Any shell scripts or code you write that uses these shells will
have a great chance of running on ANY FreeBSD system out there. That's
where traditionalism stops and personal preference jumps in though...
I don't like using csh(1) for a lot of things. It syntax makes me
cringe, even though it's a mostly "ok" interactive shell. So I always
install at least bash and mksh on my systems.
There is no bash shell in the *base* system of FreeBSD. But there are
many ports for command shells, and bash is part of these:
# cd /usr/ports/shells
44bsd-csh dash jailkit pdksh tcshrc
Makefile es ksh93 pear-PHP_Shell v7sh
bash esh lshell psh viewglob
bash-completion fd mksh rc vshnu
bash-static fish nologinmsg rssh wapsh
bash3 flash osh sash zoidberg
bash3-static gscommander p5-Shell-Perl scponly zsh
bashc heirloom-sh p5-Term-ShellUI shell-include
ch ibsh pash tcsh_nls
You can always install bash with "pkg_add". The default package is not
built as a static binary, but you can compile a static bash binary from
# cd /usr/ports/shells/bash
# make WITH_STATIC_BASH=1 install clean
The bash shell depends on two other ports: gettext and libiconv. These
are not large ports, but it is often a good idea to have a shell around
that only depends on libc.
This is why I also install 'shells/mksh' on my systems. It's the ksh
compatible shell of the MirOS BSD folks. It has a small foot-print, a
ksh-compatible syntax, and it depends only on libc.so:
keramida at kobe:/home/keramida$ ldd `which mksh`
libc.so.7 => /lib/libc.so.7 (0x280c9000)
More information about the freebsd-questions