prints a sorted list of nearby wlans.

wlan-scanner.sh

#!/bin/sh

#sudo iwlist wlan0 scan | \				# find all nearby wlans
#	grep -E 'Freq|Quality|ESSID' | \		# select details we care about
#	tr '\n' ' ' | \					# remove newlines for easier sed parsing
#	sed -r 's/\s+/ /g' | \				# remove superflous spaces
#	sed 's/:/: /g' | \				# add a space after each colon (in our case after "Frequency")
#	sed -r 's/( [1-9]\))/ \1/g' | \			# Indent 1-digit channels so they line up nicely
#	sed 's/ Freq/\nFreq/g' | \			# re-add newlines (one line for each wlan)
#	sed -r 's/(Quality|Signal|ESSID)/\t\1/g' | \	# tab output so it lines up
#	sort | \					# well…
#	tail -n +2					# cut the leading empty lines

sudo iwlist wlan0 scan | \
	grep -E 'Freq|Quality|ESSID' | \
	tr '\n' ' ' | \
	sed -r 's/\s+/ /g' | \
	sed 's/:/: /g' | \
	sed -r 's/( [1-9]\))/ \1/g' | \
	sed 's/ Freq/\nFreq/g' | \
	sed -r 's/(Quality|Signal|ESSID)/\t\1/g' | \
	sort | \
	tail -n +2