cross-posted from: https://lemmy.run/post/15922
Running Commands in Parallel in Linux
In Linux, you can execute multiple commands simultaneously by running them in parallel. This can help improve the overall execution time and efficiency of your tasks. In this tutorial, we will explore different methods to run commands in parallel in a Linux environment.
Method 1: Using
&
(ampersand) symbolThe simplest way to run commands in parallel is by appending the
&
symbol at the end of each command. Here’s how you can do it:command_1 & command_2 & command_3 &
This syntax allows each command to run in the background, enabling parallel execution. The shell will immediately return the command prompt, and the commands will execute concurrently.
For example, to compress three different files in parallel using the
gzip
command:gzip file1.txt & gzip file2.txt & gzip file3.txt &
Method 2: Using
xargs
with-P
optionThe
xargs
command is useful for building and executing commands from standard input. By utilizing its-P
option, you can specify the maximum number of commands to run in parallel. Here’s an example:echo -e "command_1\ncommand_2\ncommand_3" | xargs -P 3 -I {} sh -c "{}" &
In this example, we use the
echo
command to generate a list of commands separated by newline characters. This list is then piped (|
) toxargs
, which executes each command in parallel. The-P 3
option indicates that a maximum of three commands should run concurrently. Adjust the number according to your requirements.For instance, to run three different
wget
commands in parallel to download files:echo -e "wget http://example.com/file1.txt\nwget http://example.com/file2.txt\nwget http://example.com/file3.txt" | xargs -P 3 -I {} sh -c "{}" &
Method 3: Using GNU Parallel
GNU Parallel is a powerful tool specifically designed to run jobs in parallel. It provides extensive features and flexibility. To use GNU Parallel, follow these steps:
Install GNU Parallel if it’s not already installed. You can typically find it in your Linux distribution’s package manager.
Create a file (e.g.,
commands.txt
) and add one command per line:command_1 command_2 command_3
Run the following command to execute the commands in parallel:
parallel -j 3 < commands.txt
The
-j 3
option specifies the maximum number of parallel jobs to run. Adjust it according to your needs.For example, if you have a file called
urls.txt
containing URLs and you want to download them in parallel usingwget
:parallel -j 3 wget {} < urls.txt
GNU Parallel also offers numerous advanced options for complex parallel job management. Refer to its documentation for further information.
Conclusion
Running commands in parallel can significantly speed up your tasks by utilizing the available resources efficiently. In this tutorial, you’ve learned three methods for running commands in parallel in Linux:
- Using the
&
symbol to run commands in the background.- Utilizing
xargs
with the-P
option to define the maximum parallelism.- Using GNU Parallel for advanced parallel job management.
Choose the method that best suits your requirements and optimize your workflow by executing commands concurrently.
Can I execute river init or bspwm config like that?