Shell Programming and Scripting

When I've got a long or hard to type file name, the following is something I like to do for convenience.

Code:

$export a=someReallyLongFileName; touch $a; chown hartmann $a
$ls
.  ..  someReallyLongFileName
$echo $a
someReallyLongFileName

But then, as you see with the echo, I have polluted my environment name space when I don't need it any more. Of course, I could always

Code:

export a=

to unset a, but I'm wondering if there's some conceptually more elegant way to do this. Thanks!

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UPDATE: Figured out at least one way to do this. Use parens.

Code:

$( export a=someReallyLongFileName; touch $a; chown hartmann $a )
$ls *
someReallyLongFileName
$echo $a

$

Please do chime in if there are others.

If namespace pollution worries you, then your solution of using brackets is neat. The enclosed commands run in a subshell so the variables evaporate after the commands have executed - though it does mean that you can't use them again if you need to access the file later.

To cut down on the typing, you could also use your shell's filename completion mechanism or use copy/paste if you've got a capable terminal emulator.

cheers

If using ksh or bash, perhaps use the unset built-in function....

Code:

$ export a=someReallyLongFileName
$ echo $a
someReallyLongFileName
$ unset a
$ echo $a

$