When i run this under shell script :

sqlplus -s dcp_owner/mal_dcp_o@maldev @Call_Path.txt $ret_val
v_tmp = $ret_val
echo v_tmp


Call_Path.txt contains the sql script.
No output for v_tmp.
if i change it to :
sqlplus -s dcp_owner/mal_dcp_o@maldev @Call_Path.txt $ret_val >$File
I can see the data exists on the File .
But i get the v_tmp.
May i know what is going on?