TIL: Carriage returns for progress bars

\r is a carriage return and you can prepend your printf with it to write over the current line.

Example that will print 1 to 100:

for n in `seq 1 100`; do sleep 1; printf "\r$n"; done

I’ve long wondered specifically which control characters were used to produce progress bars on the terminal. Today I learned it’s really easy! Neat!

Caveat it’s only replacing characters. If your previous string was longer than the current one you’ll have hangovers. You can see it with this command:

for n in longer med s; do printf "\r$n"; sleep 2; done