1.0.0[−][src]Function std::env::var_os
pub fn var_os<K: AsRef<OsStr>>(key: K) -> Option<OsString>
Fetches the environment variable key
from the current process, returning
None
if the variable isn't set.
Panics
This function may panic if key
is empty, contains an ASCII equals sign
'='
or the NUL character '\0'
, or when the value contains the NUL
character.
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) }Run