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# 1  
Old 12-17-2010
Learning - Why does this bit of code fail
In bash:

Code:
for i in 1 2 3 4 5
do
    tmp_${i}=$i
    echo $i
done

It gives error on executing tmp_1=1, and so on...

Why? If I executed this in prompt, not from script, it shouldn't make a subshell should it?

Moderator's Comments:
Mod Comment please use "code" tags! thanks...
Last edited by DukeNuke2; 12-17-2010 at 08:52 PM..
# 2  
Old 12-17-2010
Use eval
Code:
 
eval "tmp_${i}=$i"

Last edited by anurag.singh; 12-17-2010 at 08:02 PM..
# 3  
Old 12-17-2010
Quote:
Originally Posted by StuartH
In bash:

for i in 1 2 3 4 5
do
tmp_${i}=$i
echo $i
done

It gives error on executing tmp_1=1, and so on...

Why?
It only evaluates variables and assignments once. So once it's done the ${i} substitution, it won't take a step back, start over, and see that you meant it to assign to the variable tmp_1. If you want it to rethink like that, you have to do so explicitly, with eval.
This User Gave Thanks to Corona688 For This Post:
StuartH
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