Introduction
In the world of Linux, the ‘export’ command is a powerful tool used to create shell variable and functions that can be passed on to child processes. This command plays a crucial role in setting environment variables in various shells. Let’s dive deeper into the functionality and usage of the ‘export’ command in Linux.
Syntax
The syntax for the ‘export’ command is straightforward:
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export VARIABLE=value
This syntax is used to create a new environment variable and assign it a value. The ‘export’ command ensures that the variable is available in the environment of any subsequent commands or shell sessions.
Examples
- Setting a variable:
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export MY_VAR="Hello, World!"
- Checking the variable:
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echo $MY_VAR
- Unsetting a variable:
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export MY_VAR=
Usage
The ‘export’ command is commonly used in shell scripts to pass variables to child processes. This ensures that the variables are available to any commands or programs that are executed within the script. Additionally, the ‘export’ command is essential when working with custom environment variables that need to be accessed by different processes or scripts.
Versions
The ‘export’ command is a standard feature in most Linux distributions, including CentOS, Ubuntu, and Debian. It is supported in various shells such as Bash, Zsh, and Ksh, making it a versatile tool for managing environment variables across different systems.
Conclusion
In conclusion, the ‘export’ command in Linux is a fundamental tool for managing environment variables and passing them to child processes. By understanding its syntax and usage, users can effectively set, access, and modify variables within their shell scripts. Whether you’re a beginner or an experienced Linux user, mastering the ‘export’ command is essential for efficient shell scripting and system administration tasks.