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Environmental variables in linux

Environmental variables in linux

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Mohd Kamaal
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2 min read

Introduction:

In server administration, environmental variables play a crucial role in configuring and managing the server environment. They provide a convenient way to store and access various settings, paths, and configurations needed by applications and scripts. This article explores the importance of environmental variables for server admins and provides a detailed tutorial on working with environmental variables in the Linux terminal for DevOps professionals.

Section 1: Managing Environmental Variables in the Linux Terminal

  • Viewing Environmental Variables

  • Command to display all environmental variables: env or printenv.

  • Viewing specific environmental variables: echo $VARIABLE_NAME

    1. Setting Environmental Variables

  • Temporary assignment: VARIABLE_NAME=value.

  • Exporting variables to make them available to child processes: export VARIABLE_NAME=value.

  • Setting variables for the current session: source script.sh or . script.sh.

    1. Persistent Environmental Variables

  • Setting variables permanently: modifying profile files (~/.bashrc, ~/.bash_profile, etc.).

  • Understanding the difference between system-wide and user-specific profile files.

  • Reloading profile files for changes to take effect: source ~/.basr.

    1. Manipulating Environmental Variables

  • Modifying existing variables: VARIABLE_NAME=new_value.

  • Appending to variable values: VARIABLE_NAME=$VARIABLE_NAME:extra_value.

  • Unsetting variables: unset VARIABLE_NAME

    1. Best Practices for Environmental Variables

  • Choosing meaningful and descriptive variable names.

  • Avoiding conflicts with existing variables.

  • Securing sensitive information in environmental variables.

Section 2: Practical Use Cases and Examples

  • Setting paths for application dependencies: Demonstrating how to set PATH variable for convenient access to executables.

  • Configuring database connection settings: Illustrating the use of environmental variables for storing database credentials.

  • Defining environment-specific configurations: Using variables to switch between development, staging, and production environments.

  • Integrating with continuous integration and deployment tools: Showcasing how to use environmental variables in CI/CD pipelines.

Section 3: Advanced Techniques

  • Using conditional statements and fallback values for environmental variables.

  • Exporting variables from one script to another.

  • Interacting with external configuration files.

Conclusion:

Environmental variables are essential tools for server administrators and DevOps professionals to configure and manage the server environment efficiently. By understanding their importance and mastering the techniques for working with environmental variables in the Linux terminal, you can streamline your workflow, improve system reliability, and enhance application deployment. Use the tutorial provided in this article as a comprehensive guide to leveraging the power of environmental variables in your server administration tasks.