Скачать или смотреть How to Send Arguments to Bash Script in GNU Parallel

Learn how to efficiently send arguments to your bash script using GNU Parallel for executing commands simultaneously, enhancing your workflow and productivity.
---
This video is based on the question https://stackoverflow.com/q/64595427/ asked by the user 'Sunchi' ( https://stackoverflow.com/u/7802905/ ) and on the answer https://stackoverflow.com/a/64597900/ provided by the user 'Sunchi' ( https://stackoverflow.com/u/7802905/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: How to send arguments to bash script in GNU parallel

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
How to Send Arguments to Bash Script in GNU Parallel

When working with multiple commands in Unix-like systems, it's common to need a quick way to execute tasks simultaneously. One powerful tool for this is GNU Parallel, which allows you to run multiple processes in parallel. However, a common issue users face is figuring out how to send arguments to their bash scripts when using GNU Parallel. In this post, we'll explore how to effectively handle this situation and enhance your command-line productivity.

Understanding the Problem

You have a bash script, bash_script.sh, that uses scp to transfer a file to multiple servers. Here’s how the script looks:

[[See Video to Reveal this Text or Code Snippet]]

While you can execute this script sequentially by running:

[[See Video to Reveal this Text or Code Snippet]]

You might want to execute the commands in parallel to save time, especially if transferring large files or working with many servers. The challenge is figuring out how to apply GNU Parallel in this context.

Solution: Using GNU Parallel

To run the commands in parallel while sending arguments to your bash script, you will need to adjust how you invoke the scp command within GNU Parallel. Here’s a minimalist approach that accomplishes your goal effectively:

Modified Script

Instead of modifying your existing script significantly, you can directly utilize the parallel command as follows:

[[See Video to Reveal this Text or Code Snippet]]

Explanation of the Command

parallel: This invokes GNU Parallel.

scp "$1": This uses the first argument passed to your script.

xxx@ {}.com:: The {} is a placeholder that GNU Parallel will replace with values from the provided list.

:::: This introduces the list that follows, which in this case is {1..5}.

{1..5}: This generates the numbers 1 through 5, replacing {} in the command to send files to xxx@ 1.com, xxx@ 2.com, xxx@ 3.com, and so on.

How to Use the Modified Command

To use the modified command, simply call your script as follows:

[[See Video to Reveal this Text or Code Snippet]]

Advantages of Using GNU Parallel

Time Efficiency: By executing commands in parallel, you significantly reduce the time required for multiple file transfers.

Simplicity: The structure remains simple and easy to understand, without the need for complex loops or additional scripts.

Flexibility: You can easily adjust the range of servers by changing the numbers in {1..5}.

Conclusion

Using GNU Parallel to execute a bash script with arguments does not have to be complicated. By incorporating GNU Parallel's capabilities into your command, you can achieve efficient parallel processing with minimal adjustments to your existing scripts. Remember, the key takeaway is modifying how you invoke the scp command within GNU Parallel, which can save you time and increase productivity.

Now, next time you need to run tasks simultaneously with arguments in bash scripts, remember this straightforward method with GNU Parallel!