What is command grouping in Linux and how to use it ?
Do you know how to group multiple commands together and redirect their output collectively to a file ?
It is a very small tip, however many of us dont know what is command grouping in Linux and how to use it.
Command Grouping and Redirection to a file
### Grouping two command: date and uptime ### Redirecting their output in one go to a file called hello.txt $ (date; uptime) > hello.txt $ cat hello.txt Sun Jul 29 23:12:38 PDT 2018 23:12 up 10 days, 4:30, 5 users, load averages: 1.26 1.23 1.25 $ date Sun Jul 29 23:12:46 PDT 2018 $ uptime 23:12 up 10 days, 4:30, 5 users, load averages: 1.37 1.26 1.26 $
Usage of Command Grouping
If you have observed above if we redirect without command grouping we need to redirect each command output individually to a file.
With command grouping we can redirect all commands output of the group to a single file in one go.
In a similar fashion, we can use command grouping in shell scripts to automate our tasks.