Simplify nmcli usage to control wifi

wifi

#! /bin/bash

# Control wifi. Since I can never remember the arguments to nmcli, I made
# this command to simplify usage.
#
# Written by Robert Bottomley
#
# $Id: wifi,v 1.4 2021/05/20 18:05:55 bob Exp $
#
# $Log: wifi,v $
# Revision 1.4  2021/05/20 18:05:55  bob
# Display help on invalid option.
#
# Revision 1.3  2021/05/20 18:01:24  bob
# Add more options beyond just on and off.
#
# Revision 1.2  2020/05/21 15:22:10  bob
# *** empty log message ***
#
#

NMCLI=/usr/bin/nmcli
HELPMSG="USAGE: wifi on | off | status | list | rescan | connect <SSID>"

if [ $# -lt 1 ] ; then
    echo $HELPMSG
    exit 1
fi

case $1 in
    on | off)
        $NMCLI radio wifi $1
        if [ $? = 1 ] ; then
            echo "Error: Unable to control radio."
            exit 1
        fi
        ;;

    status)
        echo "Wifi radio `$NMCLI radio wifi`"
        $NMCLI connection show --active
        ;;

    list | rescan)
        $NMCLI device wifi $1
        ;;

    connect)
        if [ $# -lt 2 ] ; then
            echo "Missing SSID"
            exit 1
        fi

        $NMCLI device wifi connect $2 --ask
        ;;

    *)
        echo "Invalid option '$1'"
        echo $HELPMSG
        exit 1
        ;;
esac