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    system/environment

    Stable

    Access, set and clear environment variables.

    Usage

    var { env } = require('sdk/system/environment');

    You can get the value of an environment variable, by accessing the property with the name of the desired variable:

    var PATH = env.PATH;

    You can check for the existence of an environment variable by checking whether a property with that variable name exists:

    console.log('PATH' in env); // true
    console.log('FOO' in env);  // false

    You can set the value of an environment variable by setting the property:

    env.FOO = 'foo';
    env.PATH += ':/my/path/'

    You can unset an environment variable by deleting the property:

    delete env.FOO;

    Limitations

    There is no way to enumerate existing environment variables, also env won't have any enumerable properties:

    console.log(Object.keys(env)); // []

    Environment variable will be unset, show up as non-existing if it's set to null, undefined or ''.

    env.FOO = null;
    console.log('FOO' in env);  // false
    env.BAR = '';
    console.log(env.BAR);       // undefined

    Document Tags and Contributors

    Contributors to this page: wbamberg
    Last updated by: wbamberg,
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