mkoura · April 2, 2016 09:33
diff --git a/nonsense.sh b/nonsense.sh
 # from a file print 10 lines that are directly before the last ten lines without using tail or head
 { tac | while read l; do [ "${i:=0}" -lt 20 -a "$i" -ge 10 ] && echo "$l"; i=$(($i + 1)); done | tac; } < file

 # monitor changes to a file without using tail -f
 while : ; do read line && echo "$line" || sleep 1; done < file
	# from a file print 10 lines that are directly before the last ten lines without using tail or head
	{ tac \| while read l; do [ "${i:=0}" -lt 20 -a "$i" -ge 10 ] && echo "$l"; i=$(($i + 1)); done \| tac; } < file

	# monitor changes to a file without using tail -f
	while : ; do read line && echo "$line" \|\| sleep 1; done < file