advantages of sh and csh ksh

[Kgreen]

Hi I would like to know what are the advantages and disadvantages of having a users shell as /usr/bin sh ksh and csh

[Michal Toth]

sh csh ksh bash tcsh zsh rc es
Job control N Y Y Y Y Y N N
Aliases N Y Y Y Y Y N N
Shell functions Y(1) N Y Y N Y Y Y
"Sensible" Input/Output redirection Y N Y Y N Y Y Y
Directory stack N Y Y Y Y Y F F
Command history N Y Y Y Y Y L L
Command line editing N N Y Y Y Y L L
Vi Command line editing N N Y Y Y(3) Y L L
Emacs Command line editing N N Y Y Y Y L L
Rebindable Command line editing N N N Y Y Y L L
User name look up N Y Y Y Y Y L L
Login/Logout watching N N N N Y Y F F
Filename completion N Y(1) Y Y Y Y L L
Username completion N Y(2) Y Y Y Y L L
Hostname completion N Y(2) Y Y Y Y L L
History completion N N N Y Y Y L L
Fully programmable Completion N N N N Y Y N N
Mh Mailbox completion N N N N(4) N(6) N(6) N N
Co Processes N N Y N N Y N N
Builtin artithmetic evaluation N Y Y Y Y Y N N
Can follow symbolic links invisibly N N Y Y Y Y N N
Periodic command execution N N N N Y Y N N
Custom Prompt (easily) N N Y Y Y Y Y Y
Sun Keyboard Hack N N N N N Y N N
Spelling Correction N N N N Y Y N N
Process Substitution N N N Y(2) N Y Y Y
Underlying Syntax sh csh sh sh csh sh rc rc
Freely Available N N N(5) Y Y Y Y Y
Checks Mailbox N Y Y Y Y Y F F
Tty Sanity Checking N N N N Y Y N N
Can cope with large argument lists Y N Y Y Y Y Y Y
Has non-interactive startup file N Y Y(7) Y(7) Y Y N N
Has non-login startup file N Y Y(7) Y Y Y N N
Can avoid user startup files N Y N Y N Y Y Y
Can specify startup file N N Y Y N N N N
Low level command redefinition N N N N N N N Y
Has anonymous functions N N N N N N Y Y
List Variables N Y Y N Y Y Y Y
Full signal trap handling Y N Y Y N Y Y Y
File no clobber ability N Y Y Y Y Y N F
Local variables N N Y Y N Y Y Y
Lexically scoped variables N N N N N N N Y
Exceptions N N N N N N N Y



Key to the table above.

Y Feature can be done using this shell.

N Feature is not present in the shell.

F Feature can only be done by using the shells function
mechanism.

L The readline library must be linked into the shell to enable
this Feature.


source: comp.unix.shell ; faqs.org

[Matti_Kurkela]

/usr/bin/sh is POSIX standard compliant shell, which means all modern Unix systems may be trusted to have something very much like it. It is based to the classic Bourne shell.
http://en.wikipedia.org/wiki/Bourne_shell


+ when you write scripts using it, the scripts should be portable to other Unix variants with less effort

- when you use a shell interactively (usually most of the time you think as "using a shell"), the more advanced shells have more convenience features than the standard shell


/usr/bin/csh is a shell that uses conventions similar to the C programming language.
http://en.wikipedia.org/wiki/C_shell

- it is definitely NOT compatible with the classic Bourne shell and its descendants

- its design has some fundamental problems: there are things you cannot do with C shell syntax. The traditional "C shell programming considered harmful" posting can be found here: http://www.faqs.org/faqs/unix-faq/shell/csh-whynot/

* if you (or your users) really want a csh-like shell for interactive use, consider installing a "Tenex C shell" (tcsh), a descendant of csh with backwards compatibility and some flaws fixed.


/usr/bin/ksh is known as the Korn shell.
http://en.wikipedia.org/wiki/Korn_shell

+ it is very much backwards compatible to the classic Bourne shell, was the basis of the POSIX shell standard and offers some extensions above and beyond that

- before year 2000 it used to be AT&T proprietary software, so it may not be as widely-known than other shells

[Bill Hassell]

csh is virtually useless due to the many incompatibilities and limitations. The /usr/bin/sh shell is the POSIX shell, virtually identical to ksh (also a POSIX standard shell), so either is a reasonable shell to learn and use. Note that /usr/bin/ksh is ksh88 (fairly old) while /usr/dt/bin/dtksh is ksh93 standard. dtksh has Xwindow programming enhancements.

Bash is also a POSIX shell that is very much like sh and ksh with a few enhancements. Bash must be downloaded as it is not supplied with the OS.

In HP-UX, /usr/bin/sh is the POSIX shell while /usr/old/bin/sh is the Bourne shell, a small subset of POSIX shells and not recommended for today's scripting. POSIX shells are by far the most portable scripting language for Unix followed by Perl.

[Steven E. Protter]

Shalom,

the right tool for the right job. Bourne and c are provided and a I know of a few third party apps that need those shells to install and start.

SEP