Serial Port Communication Commands

To find list of serial port

# dmesg | grep tty

To find list of serial ports of the current linux system

# setserial -g /dev/ttyS[0123]

To find the list of groups with which current user is associated

# groups ${USER}

To add user "test" to a group "dialout"

#usermod -a -G dialout test

Command to check the signals of the Serial port

#cat /proc/tty/driver/serial

This will display the information about, RTS | DTR | DSR | CTS | CD signals.