Useful commands

Terminal

Reload current shell in place (useful for cleanly applying recent shell config updates)

exec $SHELL

Show current shell level (increases when launching additional shells via bash, zsh etc)

echo $SHLVL

Clear the current screen of text

clear

Timing

Time current command execution and output user and system timing information

time <command>

Prevent sleep

Prevent computer from sleeping and declare user as active

caffeinate -u -t <seconds>

Other caffeinate options

• -d Prevent display sleep

• -i Prevent system idle sleep

• -m Prevent disk idle sleep

Generate MD5 and SHA1 hashes

Generate MD5 hash from file

md5 <file>

Generate SHA1 hash from file

shasum <file>

Math utilities

General maths interpreter (allows general equations entered into command line)

bc

Calculate result of math query using bc

echo <calculation> | bc
echo '5 * 8' | bc