How to Pass Specific Variables Between Shell Scripts in Bash Using export

Learn how to effectively pass variables between two shell scripts in Bash with the `export` command for better scope control.
---
This video is based on the question https://stackoverflow.com/q/70831287/ asked by the user 'sanjeewa' ( https://stackoverflow.com/u/3012493/ ) and on the answer https://stackoverflow.com/a/70832892/ provided by the user 'Dudi Boy' ( https://stackoverflow.com/u/6266192/ ) 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: Pass specific variables from one shell script to another?

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

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Passing Variables Between Shell Scripts in Bash

When you're working with Bash scripts, you might come across a situation where you need to pass variables from one script to another. This can be a bit tricky, especially when dealing with functions like jumpto that can change how variables are interpreted. In this guide, we'll discuss how to correctly pass variables, using the example of test.sh and test2.sh. Let's dive in!

The Problem

Imagine you have two Bash scripts: test.sh and test2.sh. In test.sh, you define a variable var1 and attempt to pass it to test2.sh. However, your script does not function as expected because the jumpto function changes the context in which var1 is used. Here’s a quick look at the scripts:

Contents of test.sh

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

Contents of test2.sh

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

The issue here is that when you use jumpto, var1 gets reassigned to $1, which may not provide the output you were aiming for. So, what can you do differently?

The Solution: Using export

To address the issue of variable scope in Bash scripts, we can use the export command. This command allows you to set environment variables that can be accessed by any child processes spawned by the script. Here’s how you can modify test.sh effectively:

Revised Contents of test.sh

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

Explanation of Changes

Using export: By adding export before var1, you’re telling Bash to make var1 a part of the environment. This means that test2.sh can now access var1 without any ambiguity.

Function Redundancy: With var1 now properly exported, you can target the variable correctly in test2.sh without worrying about it being overridden or confused with other positional parameters.

Why This Works

When var1 is exported, it becomes accessible to all subsequent commands and scripts. Thus, test2.sh will be able to access and print the value of var1 directly:

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

Benefits of Using export

Simplifies variable sharing: Makes it easy to share variables across scripts.

Increases maintainability: Reduces complexity by ensuring clarity in variable references.

Conclusion

Being able to pass variables between shell scripts is a powerful feature of Bash scripting. By utilizing the export command, you can ensure that your scripts communicate effectively and maintain easy-to-understand variable assignment. If you follow these adjustments, you’ll find that working with shell scripts becomes much more manageable and less prone to errors. Happy scripting!

Видео How to Pass Specific Variables Between Shell Scripts in Bash Using export канала vlogize