BASH variable referencing

SwingingSimian · 10-16-2008, 04:54 AM

Hi all

Another no brainer(I must have left mine at home today). I'm sure I have done this before but I can't figure it out.

This is also very similar to one of my previous posts about indirect referencing, but slightly different.

I want to set a varaible such that it updates it's value with reference to another variable. Much like aliasing can do with single quotes.

e.g.

>bar=test
>foo=$bar

>echo $foo
>test

>bar=test1
>echo $foo
>test1

Indirect referencing isn't quite what I want for this, but I'm sure there is something very obvious that I've missed.

Thanks

Nath

Mr. C. · 10-16-2008, 05:03 AM

See indirect expansion in man bash:

Code:

$ bar=test    
$ foo=bar     
$ echo ${!foo}
test

SwingingSimian · 10-16-2008, 05:11 AM

I've already looked at this and it doesn't do quite what I want as it forces me to use the ${!foo} notation. As I am potentially directly setting foo to another value, I want this to work by simply using "$foo".

Thanks

Nath

Mr. C. · 10-16-2008, 05:20 AM

Your example shows foo as being as being the thing you dereference, and it points to bar. And bar contains a value. Can you show an example of something that doesn't follow this classic indirection problem example?