More useful UNIX commands.

Posted: December 27, 2011. At: 9:44 PM. This was 6 years ago. Post ID: 2327
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Time a UNIX command. the time(1) command will tell you how long it took for a command to execute.

ubuntu ~ $ sudo time find / -name dpkg.log
0.82user 1.82system 0:34.04elapsed 7%CPU (0avgtext+0avgdata 2260maxresident)k
679328inputs+0outputs (2major+4374minor)pagefaults 0swaps

Listing all logged in users on your UNIX/Linux system. This command uses the finger(1) command to list all users and print the information in a user friendly manner.

ubuntu ~ $ finger -lmps $LOGNAME | sed -e "s/On/Logged in/g" | grep "since"
Logged in since Wed Dec 27 21:42 (UTC) on pts/0 from

Tree view for the ps command.

ubuntu ~ $ pstree -a -u -G -l -h -p | head -n 20
  ├─acpid,1272 -c /etc/acpi/events -s /var/run/acpid.socket
  ├─apache2,4233 -k start
  │   ├─apache2,26326,www-data -k start
  │   ├─apache2,26327,www-data -k start
  │   ├─apache2,26328,www-data -k start
  │   ├─apache2,26329,www-data -k start
  │   ├─apache2,26330,www-data -k start
  │   └─apache2,28733,www-data -k start
  ├─atop,7187 -a -w /var/log/atop/atop_20171227 600
  ├─dbus-daemon,947,messagebus --system --fork
  ├─dhclient,573 -1 -v -pf /run/ -lf /var/lib/dhcp/dhclient.eth0.leases eth0
  ├─getty,1234 -8 38400 tty4
  ├─getty,1237 -8 38400 tty5
  ├─getty,1241 -8 38400 tty2
  ├─getty,1242 -8 38400 tty3
  ├─getty,1245 -8 38400 tty6
  ├─getty,1771 -8 38400 tty1

Human readable directory size display. This is a very useful command indeed for finding just how much space a certain folder is taking up on your hard drive.

ubuntu ~/Documents $ du -ack -BM | sort -nr | head -n 20
74M     total
74M     .
23M     ./wpscan
20M     ./
19M     ./wpscan/.git/objects/pack/pack-9d321cf60e3e0fedc838fe768822143c3fd91cbe.pack
19M     ./wpscan/.git/objects/pack
19M     ./wpscan/.git/objects
19M     ./wpscan/.git
17M     ./impacket-read-only
10M     ./SYSTEM
7M      ./impacket-read-only/.svn/pristine
7M      ./impacket-read-only/.svn
5M      ./python/pycrypto-2.6
5M      ./python
5M      ./impacket-read-only/impacket
5M      ./impacket-read-only/build/lib.linux-x86_64-2.7/impacket
5M      ./impacket-read-only/build/lib.linux-x86_64-2.7
5M      ./impacket-read-only/build
2M      ./wpscan/spec/samples
2M      ./wpscan/spec

Using apt to check what updates are available for your Ubuntu or Debian system.

ubuntu ~/Documents $ apt list --upgradable

This command will install all pending updates to your Debian/Ubuntu system.

ubuntu ~/Documents $ sudo apt upgrade
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