#bash #coding #programming #linux #sh

What's is the best way to do an infinite loop in BASH?

Here are some ways to do an infinite loop in BASH, using the no-op builtin (:) inside the loop…

while :;do :;done

while [[ hellnotfrozen ]];do :;done

for ((0;;));do :;done

for ((;;));do :;done

until [[ ! hellnotfrozen ]];do :;done

until [ ! hellnotfrozen ];do :;done

The first “while” loop is the most compact in terms of characters to type, and it doesn’t require the shift key like the “for” loops do – to type the “(())”.

The first “until” loop and the last "while" loop use the BASH compound command for conditional expressions and are more verbose, but they're self-commenting and much more readable and comprehensible. The "until" loop is the fastest executing (using my crude benchmark tests).

The second “until” loop uses the builtin BASH “test” command instead of the compound command, but it executes much more slowly than any of the others.