#!/bin/sh
# Petr Simandl www.simandl.cz
# listing of all possible channels of given wifi card

chmin=1
chmax=240

if [ "$1 x" = " x" ]
    then
      echo "Missing interface name"
      echo "Usage: $0 <interface>"
      exit 1
fi

for channel in `seq $chmin $chmax`
do
  iwconfig $1 channel $channel 2>/dev/null && ( echo -n "	Channel " ; echo -n "$channel : " ; \
  iwlist $1 freq | grep Freq | sed 's/Current Frequency://' | sed 's/GHz//' | awk '{print $1" GHz"}'
  ) 
done