use warnings;
use strict;
use IPC::Run3 'run3';

my $in = " string argument passed ";
my @cmd = ('/path/to/shellscript.sh');

run3 \@cmd, \$in, \my @out or die "run3 failed";
$?==0 or die "command failed, \$?=$?";

chomp(@out);
print "<<$_>>\n" for @out;