helix-plus/helix-view/src/env.rs

pub fn binary_exists(binary_name: &str) -> bool {
    which::which(binary_name).is_ok()
}

#[cfg(not(windows))]
pub fn env_var_is_set(env_var_name: &str) -> bool {
    std::env::var_os(env_var_name).is_some()
}