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eval misconception

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# 1  
Old 12-02-2008
eval misconception
Hi, I have two files "foo" and "bar"

Code:
 $ cat foo
a is \$a and b is \$b

Code:
$ cat bar
car tree

using the below 'while' loop I expect the output to be: a is car and b is tree
Code:
while read a b; do
     eval echo $(cat foo)           # o/p: a is $a and b is $b
     eval "echo $(eval "cat foo")"  # o/p: a is $a and b is $b
done < bar

rather getting the one which I mentioned as 'o/p'. I am not very sure about eval, how it works, so pls explain and correct me where I have gone wrong.
Last edited by royalibrahim; 12-02-2008 at 05:23 AM..
# 2  
Old 12-02-2008
Hi,

Code:
while read a b < bar

Code:
while read line; do echo $(eval "echo $line"); done < foo

whill give you the output:

Code:
a is car and b is tree

HTH Chris
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