Shell Quoting. Was: Shell tips and tricks

[Ben Scott]

On 10/8/07, Tom Buskey <tom at buskey.name> wrote:
> Make sure you start your script with #!/bin/bash or #!/bin/ksh.  $(...) does
> not exist in Bourne shell so you shouldn't expect #!/bin/sh to have it.

  Didn't we already have this discussion?  :-)

> On a similar note, why would you use [[...]] instead of [...] ?

  According to Ye Olde FM, "word splitting and pathname expansion are
not performed on the words between the [[ and ]]", but I've never used
that particular construct in practice.  Perhaps as an alternative to
quoting individual arguments?

  I've used $(( ... )) for arithmetic before.  It's faster than
calling the external expr(1) program, generally doesn't need quoting,
nests nicely, and looks better.

-- Ben