It's considered "best" to always use /bin/sh, as that will work with whatever sh-compatible shell that's native to the system. Unless you actually need bash-shell extensions (it can do a bit more than good old sh).

To find out if you have bash you can use several methods, e.g.
or, if you are already executing a bash-lookalike (e.g. ash) you can do
On my tablet there's no bash, so try 'ash' instead with the above commands. It should output /bin/ash.

Hi,

I installed bash for OS2007HE to access arrays.
Writing first shell script was a nightmare for me
as maemo has small screen I edited shell files on PC running Win XP
than saved a file as text .sh , moved to memory card,
moved to /home/user
chmod and tried to use,
forgetting to dos2unix.exe it first.

Installed gainroot, mc
and today try to edit basic shell script in mc's editor.

Installed dialog too to have some DOS-like interaction + menu
to run test shell scripts in sh and bash.

darius

Thanks, no bash found but 'which ash' found bin/ash

Most ppl seem to be saying use bin/sh so for what I'm doing this looks to be the best approach right now.

Again, thanks to all.

On early UNIX, (when the Bourne shell was the most advanced Bourne-compatible shell), it lived as /bin/sh.
Now there are at least three Bourne-compatible shells in common use:

• ash - Almquist SHell; this was originally a clone of an some Bourne shell (sysvr4?), and deliberately lacks extended features. (There's several variants; we have busybox ash by default.)
• bash - Bourne Again SHell; GNU clone of bash with a truckload of features.
• ksh - Korn SHell; This is another classic UNIX shell, designed with a focus on scripting, as well as enhanced interactive use from csh, and backwards compatibility to sh. (There's several variants here, too...)
• zsh; less commonly used, but attempts to incorporate the benefits of bash, ksh, and tcsh. Most notable use is probably Darwin and derivatives.

On most modern UNIXen, there's no binary at /bin/sh; it's a symlink to some Bourne-compatible shell (usually with extensions). But it's always there, and should always be nominally compatible. So by writing scripts using a portable subset of what your /bin/sh knows, and using /bin/sh as an interpreter, your script can work on any UNIX.

Sven Mascheck has some more info on portability, and on shell history in general, at his site. Good reading.

But bottom line is: shebang for /bin/sh, and if it runs on ours (busybox ash), it's a decent bet it'll work everywhere else.

Yup - Benson's got it right.

Write your script using basic sh (available on almost every unix) - and then it will be portable across many.

I've been doing it this way for years - moving scripts from solaris/sys 5/linux/bsd and even the pc with the gnu tools.

Fix the paths - and then go!