All things command-line wizardry.
# one-line if statements if true; then echo "Do something"; fi # => Do something if false; then echo "Do something"; fi # =>
# one-line for statements for i in hello there; do echo $i; done # => hello # => there for i in $(seq 1 3); do echo $i; done # => 1 # => 2 # => 3
You'll often need to run a command over and over again for some reason (mine right now is: I have to check if a file exists). There are obviously better options - but doing things through command-line ninjutsu is always funnier. So, one-line infinite loops in Shell (both sh and Bash):
while true; do echo "Doing some work" && sleep 1; done # => Doing some work # => Doing some work # => Doing some work # => ...
This will run
echo "Hello!" forever, "sleeping" for one second between each execution.