export command in Linux
The Linux terminal has many environment variables that contain necessary information about the system. Also, applications may require some environment variables in order to execute.
exportThis article will use the command to define an environment variable in Linux .
exportVariables with commands in Linux
exportThe command is used to create environment variables. You can use the command in the Linux terminal envto get 当前环境the variables.
env
Output:
As shown in the above command output, many information such as path, session, time, etc. are stored as envvariables. However, these variables are not always enough.
Some values that the application needs to use at runtime can be obtained from environment variables. The value may be API key, Usernameor may be Password.
We use exportthe command to define these variables. Example usage is as follows.
export API_KEY=test12345
With this command, API_KEYit is now an environment variable. When we use envthe command again, we can see that this variable is also in the list.
This variable can now be accessed and used from the current terminal and its child processes.
However, it is not accessible from the parent process.
/bin/sh
echo $API_KEY
Output:
To create Persistent Environmentvariables, add them to .bashrca file like . Also, this command API_KEY=test12345is different from the command.
When the command is not used export, the variable is not passed to the child process. It only operates in the current terminal.
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