Oracle listener control utility doesn’t allow to set the password non-interactively.
In this case the small Perl script, using Expect, could help.
#!/usr/bin/perl
use Expect;
my $exp = new Expect;
my $command = 'lsnrctl';
my $PROMPT='LSNRCTL>';
my $LISTENER_NAME=$ARGV[0] ;
my $NEW_PASSWORD=$ARGV[1] ;
print "Changing pasword for ${LISTENER_NAME} \n" ;
$exp->spawn($command) or die "Cannot spawn $command: $!\n";
$exp->stty(qw(echo));
my $answer = $exp->expect(30, 'LSNRCTL>');
$exp->send("set current_listener ${LISTENER_NAME}\n");
$answer = $exp->expect(30, $PROMPT);
$exp->send("change_pass\n");
# For localized version should be changed (i.e. just to ':')
$answer = $exp->expect(30, 'Old password:');
# It's supposed, that listener still doesn't have the password
$exp->send("\n");
$answer = $exp->expect(30, 'New password:');
$exp->send("${NEW_PASSWORD}\n");
$answer = $exp->expect(30, 'Reenter new password:');
$exp->send("${NEW_PASSWORD}\n");
$answer = $exp->expect(30, $PROMPT);
$exp->send("set password\n");
$answer = $exp->expect(30, 'Password:');
$exp->send("${NEW_PASSWORD}\n");
$answer = $exp->expect(30, $PROMPT);
$exp->send("save_config\n");
# Restart it if necessary
# $answer = $exp->expect(30, $PROMPT);
# $exp->send("reload\n");
$answer = $exp->expect(30, $PROMPT);
$exp->send("exit\n");
exit;