如何每N秒重复运行bash脚本？

Question

I have a shell script printing some statistics like disk info, memory use and so on. But it shows information only once after the script runs and exits. Can I make this script be run repeatedly (like htop for example) or something like that? I want this info to be updated every 5-10 seconds.

Answer 1

In linux you can use the watch program to repeat an action. Assuming that script.sh is executable:

watch -n 10 path/to/script.sh

Would run it every 10 seconds.

To make your script executable, you can use chmod +x script.sh . Don't forget to add the shebang

#!/bin/bash

to the first line (assuming that it's a bash script).

If you're running the script from your current directory, you can then do:

watch -n 10 ./script.sh

Answer 2

A slight improvement to my comment: if your script exits with true (eg when it ends with exit 0 ), you can run

while script; do sleep 10; done

This is the canonical way to repeat a command as long as it doesn't fail.

Answer 3

As mentioned in a comment you need to wrap the script in an unconditional loop:

while :; do script; sleep 10; done

Depending on the script logic instead of the sleep 10 you may want to put different for instance the read - for the input data on the file/socket stdin. This will assure you script will not wake until some data to process will be present and if the data will be present the script will not take any time to wake.