For starters, if you can make the assumption that Bash is preinstalled (which, to my knowledge is the case on all the systems you list), use the following hashbang to be compatible:
this invokes whatever
bash happens to be configured, no matter whether it's in
While on most systems across a wide range (including AIX, Solaris, several BSD flavors),
bash ended up in different locations,
env always ended up in
/usr/bin/env. The trick, however, is not mine but from the author of the Bash Cookbook.
Anyway, yes Bash would allow you to use some "modern" features that make your life easier.
For example the double brackets:
[[ -f "/etc/debian_version" ]] && echo "This is a Debian flavor"
whereas in traditional shell dialects you'd have to resort to:
test -f "/etc/debian_version" && echo "This is a Debian flavor"
but the best about the double brackets is that they allow regular expressions for matching. The Bash Hackers Wiki will give you many tricks in that direction.
You can also use quite convenient expressions like
$((2**10)) or other arithmetic expressions inline with the
Using backticks for subshells is fine, albeit a bit outdated. But the nesting capabilities of
$(command ...) invocations are way more convenient as you won't have to escape many things at different subshell levels.
These are but a few things Bash gives you over the traditional common POSIX
But if you want more power on the shell (not just in scripts), also have a look at