How to set and manage Linux environment variables

How to set and manage Linux environment variables requires specific code examples

In the Linux operating system, environment variables are dynamic values ​​stored in the operating system. They are used to control the behavior and output of various programs. Setting and managing environment variables is very important in Linux systems. This article will introduce how to set and manage Linux environment variables, with specific code examples.

1. View environment variables

In Linux systems, we can view the value of environment variables through the echo $VARIABLE_NAME command, such as viewing the PATH environment The value of the variable can be determined using the echo $PATH command.

2. Set temporary environment variables

To set temporary environment variables, you can use the export command, for example:

export VARIABLE_NAME=value

hereVARIABLE_NAME is the name of the environment variable, value is the value of the environment variable. Once set, this environment variable is only valid in the current session.

3. Set permanent environment variables

To set permanent environment variables, you can edit /etc/profile, ~/.bashrc or ~/.bash_profile and other files, add the following content:

export VARIABLE_NAME=value

Then run source /etc/profile or source ~/.bashrcMake environment variables effective.

4. Manage environment variables

You can delete existing environment variables through the unset command, for example:

unset VARIABLE_NAME

This will Delete the environment variable named VARIABLE_NAME.

5. Example

The following is a specific example that demonstrates how to set up an environment named MY_VARIABLE with a value of hello Variable:

export MY_VARIABLE=hello
echo $MY_VARIABLE

After running the above code, if no error is reported, it means that the value of the environment variable MY_VARIABLE is successfully set to hello, and echo $ MY_VARIABLE can verify the value of environment variables.

Through the above steps, you can easily set and manage Linux environment variables. Remember to choose how to set environment variables temporarily or permanently according to your own needs, and verify whether the environment variables are set successfully in a timely manner. Hope the above content is helpful to you.

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