ZacharyZhang-NY
b7fca0146d
ElyDoc, ElyTable, ElyShow (LibreOfficeKit), ElyPDF (MuPDF), ElyTree (Git), ElyMark (Milkdown and CodeMirror in CEF). ElyMail and ElyAgent follow.
37 lines
1.0 KiB
Rust
37 lines
1.0 KiB
Rust
/// An environment variable's text; none when unset.
|
|
pub fn value(name: &str) -> Option<String> {
|
|
std::env::var_os(name).map(|value| value.to_string_lossy().into_owned())
|
|
}
|
|
|
|
/// A 0 or 1 switch; anything else warns.
|
|
pub fn flag(name: &str) -> Option<bool> {
|
|
flag_from(name, value(name).as_deref())
|
|
}
|
|
|
|
fn flag_from(name: &str, value: Option<&str>) -> Option<bool> {
|
|
match value {
|
|
None => None,
|
|
Some("1") => Some(true),
|
|
Some("0") => Some(false),
|
|
Some(other) => {
|
|
log::warn!("env: {name}={other} is not 0 or 1, ignored");
|
|
None
|
|
}
|
|
}
|
|
}
|
|
|
|
#[cfg(test)]
|
|
mod tests {
|
|
use super::flag_from;
|
|
|
|
#[test]
|
|
fn only_zero_and_one_are_answers() {
|
|
assert_eq!(flag_from("X", Some("1")), Some(true));
|
|
assert_eq!(flag_from("X", Some("0")), Some(false));
|
|
assert_eq!(flag_from("X", None), None);
|
|
for other in ["", "true", "false", "off", "yes", " 1", "01"] {
|
|
assert_eq!(flag_from("X", Some(other)), None, "{other:?}");
|
|
}
|
|
}
|
|
}
|