# grep -a -B10 -A100 -i fibonacci /dev/hda2 > fabonacci.out
a. searching string fibonacci in partition /dev/hda2, it was in a deleted file.
b. you need a few Mbytes free on the partition while running this command
-a treat device as a series of ASCII characters
-BN before N line
-AN after N line
-i not case-sensitive