modemtest -V (return code: 255)
Use of uninitialized value $signature in string eq at /usr/lib/x86_64-linux-gnu/perl5/5.26/Device/SerialPort.pm line 613.
Use of uninitialized value $signature in concatenation (.) or string at /usr/lib/x86_64-linux-gnu/perl5/5.26/Device/SerialPort.pm line 614.
Invalid signature in -version: at /usr/bin/modemtest line 117.
new(-version):
Device::SerialPort v1.40.0 loaded.
modemtest --help (return code: 255)
Usage: /usr/bin/modemtest [DEVICE [BAUD [DATABITS [PARITY [STOPBITS [FLOW]]]]]]
-h, --help Help report
--skip-status Skip modem status bit tests
--hide-possible Don't show all possible settings
Device::SerialPort v1.40.0 loaded.