Chapter 8: File and User Information Utilities

Commands:

Command Description Examples
find The find utility recursively descends the directory hierarchy for each path seeking files that match a Boolean expression. -o

$ find /home/user2 -name 'dir*'
/home/user2/dir2
/home/user2/dir3

grep Searches a file for a pattern. -i

$ grep banana ./*
/home/user2/fruit: banana
/home/user2/fruit.tar:banana
/home/user2/fruit2: banana
/home/user2/fruit2.tar:banana
id Returns the user identity. -a

$ id
uid=1002(user2) gid=10(staff)

$ id -a
uid=1002(user2) gid=10(staff) groups=10(staff)
sort The sort command sorts lines of all the named files together and writes the result on the standard output. $ sort file1

$ sort +1n file2

su Allows a user to become super user or another user - username

$ su -student6
Password:
$
who Lists who is on the system. 0H,-q

$ who
user2 console  Apr 30 12:37   (:0)
user2 pts/4    Apr 30 12:40   (:0.0)
$

who am i Displays the effective current username. $ who am i
user2 pts/4    Apr 30 12:40   (:0.0)
whoami Displays the effective current username $ whoami
user2