std::env::var - Rust
Description: API documentation for the Rust `var` fn in crate `std`.
Keywords: rust, rustlang, rust-lang, var

# 1.0.0[−][src]Function std::env::var

    pub fn var<K: AsRef<OsStr>>(key: K) -> Result<String, VarError>

Fetches the environment variable `key` from the current process.

# Errors

- Environment variable is not present
- Environment variable is not valid unicode

# 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(key) {
        Ok(val) => println!("{}: {:?}", key, val),
        Err(e) => println!("couldn't interpret {}: {}", key, e),
    }Run

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