/usr/bin/ssh hostname "echo test\$ing | /usr/bin/passwd --stdin bob" #### /.../bin/sh -c '/usr/bin/ssh hostname "echo test\$ing | /usr/bin/passwd --stdin bob"' #### /usr/bin/ssh hostname "echo test\$ing | /usr/bin/passwd --stdin bob" #### echo test$ing | /usr/bin/passwd --stdin bob #### $ echo 'test\$ing' test\$ing $ echo "test\$ing" test$ing #### my $set_password = '/usr/bin/ssh ' . $master_host . " \"echo \Q$new_password\E | /usr/bin/passwd --stdin \Q$username\E\""; #### my $set_password = '/usr/bin/ssh ' . $master_host . " 'echo \Q$new_password\E | /usr/bin/passwd --stdin \Q$username\E'";