# Function bitflags::__core::env::var_os [−] [src]

    pub fn var_os<K>(key: K) -> Option<OsString> where K: AsRef<OsStr>

1.0.0

Fetches the environment variable `key` from the current process, returning `None` if the variable isn't set.

# Examples

    use std::env;

    let key = "HOME";
    match env::var_os(key) {
        Some(val) => println!("{}: {:?}", key, val),
        None => println!("{} is not defined in the environment.", key)
    }

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