tldr/pages/common/while.md

# while

> Simple shell loop.
> More information: <https://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_09_04_09>.

- Read `stdin` and perform an action on every line:

`while read line; do echo "$line"; done`

- Execute a command forever once every second:

`while :; do {{command}}; sleep 1; done`
for/if/while: add 2016-01-05 20:47:12 +02:00			`# while`

Reformatted pages once more 2016-01-13 12:04:46 +01:00			`> Simple shell loop.`
while: replace incorrect link (#10579) 2023-08-08 13:21:15 +03:00			`> More information: <https://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_09_04_09>.`
for/if/while: add 2016-01-05 20:47:12 +02:00
*: always backquote `stdin`, `stdout` and `stderr` (#9584) 2022-12-04 08:53:34 +01:00			- Read `stdin` and perform an action on every line:
for/if/while: add 2016-01-05 20:47:12 +02:00
			`while read line; do echo "$line"; done`

Reformatted pages once more 2016-01-13 12:04:46 +01:00			`- Execute a command forever once every second:`
for/if/while: add 2016-01-05 20:47:12 +02:00
			`while :; do {{command}}; sleep 1; done`