mdig -version (return code: 0)
mDiG 9.11.3-1ubuntu1.3-Ubuntu
mdig --help (return code: 1)
Invalid option: --help
Usage: mdig @server {global-opt} host
{local-opt} [ host {local-opt} [...]]
Use "mdig -h" (or "mdig -h | more") for complete list of options