external procedure-return multiple records from database

[rexma]

Hi all

Our aim is to return DB multple records using the from external proc
we have used below shell script command:
vsql -c " select columname from table "

while invoking the shell script it is returning the result correctly
sh shellname.sh

but while invoking through external proc the output is not coming.please refer the code used

#! bin/bash
vsql -c "vsql -c " select columname from table"
exit 0

also we have used export and set try to return the result as follows
export res =vsql -c "vsql -c " select columname from table"
\set res vsql -c "vsql -c " select columname from table"

it is also not working

please suggest as a best way