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Indirect variable assignment

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# 1  
Old 10-04-2010
Indirect variable assignment
Hi

I have variable A_B=alpha
also var1="A"
var2="B"

I want to retrieve the value alpha using var1 and var2 , somthing like
echo ${${var1}_${var2}} that works. Obviously this is receiving syntax
error
# 2  
Old 10-04-2010
Use this:

Code:
$ A_B=alpha
$ var1="A"
$ var2="B"
$ eval echo \${${var1}_${var2}}
alpha

# 3  
Old 10-04-2010
try with eval:

Code:
eval echo \${${var1}_${var2}}

# 4  
Old 10-04-2010
Code:
V=${var1}_${var2}
$ echo ${!V}

# 5  
Old 10-04-2010
Quote:
Originally Posted by frans
Code:
V=${var1}_${var2}
$ echo ${!V}

In which shell should this work? I tried it with
  • bash ... empty output
  • ksh ... bad substitution
  • zsh ... prints "A_B"
Smilie
# 6  
Old 10-04-2010
Quote:
Originally Posted by hergp
In which shell should this work?
Smilie
Works in bash from version 2
# 7  
Old 10-04-2010
Strange, it works now, but it did not work the first time I tried (empty output). Must have mistyped something.

Anyway, thanks for the clarification.
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