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Function std.process.environment.get

Retrieves the value of the environment variable with the given name, or a default value if the variable doesn't exist.

static string get (
  scope const(char)[] name,
  string defaultValue = null
) @safe;

Unlike environment.opIndex, this function never throws on Posix.

auto sh = environment.get("SHELL", "/bin/sh");

This function is also useful in checking for the existence of an environment variable.

auto myVar = environment.get("MYVAR");
if (myVar is null)
{
    // Environment variable doesn't exist.
    // Note that we have to use 'is' for the comparison, since
    // myVar == null is also true if the variable exists but is
    // empty.
}

Parameters

NameDescription
name name of the environment variable to retrieve
defaultValue default value to return if the environment variable doesn't exist.

Returns

the value of the environment variable if found, otherwise null if the environment doesn't exist.

Throws

UTFException if the variable contains invalid UTF-16 characters (Windows only).

Authors

Lars Tandle Kyllingstad, Steven Schveighoffer, Vladimir Panteleev

License

Boost License 1.0.