Hi,

I want to stubstitute variable in sed using combination of name and var_$name:

name=Tom
var_$name=1

sed -n "${var_"$name"}"p < myfile

but it doesn't work, do you know what's wrong ?

Thanks

your problem is that the variables are not being expanded in the order you need. For exactly this is the 'eval' command, which restarts the interpretation process of the shell.

notice the difference:

# myvar="foo"
# var='$myvar'
# echo $var
$myvar
# eval echo $var
foo

The next to last line will first evaluate to "eval echo $myvar", then eval will restart the evaluation process resulting in "echo foo", which is in turn being displayed.

bakunin