For example:
a=s1;b=s2; for i in $a $b ; do echo $i ; done
I want to get a and b NOT s1 and s2
How could I do it?
If you are using bash or ksh, indirect parameter expansion is safer than using eval.
a=s1
b=s2
for i in a b; do
echo "$i=${!i}"
done
If you are using zsh, the syntax is slightly different.
for i in a b; do
echo "$i=${(P)i}"
done
Other shells might have different syntax; check its documentation for details.
If you are using a shell (e.g. /bin/sh or dash) without indirect parameter expansion, you'll have to use eval:
for i in a b; do
eval "echo $i=\$$i"
done
Here, eval is safe because you had explicit control over the value of i. In general, any parameters expanded in the argument to eval should be validated to ensure you don't execute code you didn't expect to.
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