OT: bash positional parameters

[michael <linux@networkingnewsletter.org.uk>]

Folks

For some reason out of my control I need to pass the name of an env var
to a bash script and then, within said script, determine the value of
that env var.

For example if my script is 'myScript' and assume I've done

	$ export INPUTFILE=/tmp/whateverandaday

then how inside myScript do I get the value of INPUTFILE when all I can
pass to the script is the name of the env var, eg

	$ ./myScript INPUTFILE

(and no I cannot pass $INPUTFILE directly for another reason [a later
part of the script calls a program which needs the env var name not its
value])

I've tried various combos inside the script like 
  echo ${$1}
but they don't work (the nearest I can get is
  set | grep $1
but that's ugly IMHP)

Cheers!

-- 
Michael Bane
Atmospheric Physics Group
University of Manchester