Finding executable in PATH with Rust -

in python can:

from distutils import spawn  cmd = spawn.find_executable("commandname") 

i tried code below, it assumes you're on unix-like system /usr/bin/which available(also involves execution of external command want avoid):

use std::process::command;  let output = command::new("which")                       .arg("commandname")                       .unwrap_or_else(|e| /* handle error here */) 

what simplest way in rust?

i'd grab environment variable , iterate through it, returning first matching path:

use std::env; use std::path::{path, pathbuf};  fn find_it<p>(exe_name: p) -> option<pathbuf>     p: asref<path>, {     env::var_os("path").and_then(|paths| {         env::split_paths(&paths).filter_map(|dir| {             let full_path = dir.join(&exe_name);             if full_path.is_file() {                 some(full_path)             } else {                 none             }         }).next()     }) }  fn main() {     println!("{:?}", find_it("cat"));     println!("{:?}", find_it("dog")); } 

this ugly on windows you'd have append .exe executable name. should potentially extended return items executable, again platform-specific code.

reviewing python implementation, appears support absolute path being passed. that's if function should support or not.

a quick search on crates.io returned 1 crate may useful: quale, although says

currently works on unix-like operating systems.

it wouldn't surprise me find out there others.

---

here's ugly code adds .exe end if it's missing, on windows.

#[cfg(not(target_os = "windows"))] fn enhance_exe_name(exe_name: &path) -> cow<path> {     exe_name.into() }  #[cfg(target_os = "windows")] fn enhance_exe_name(exe_name: &path) -> cow<path> {     use std::ffi::osstr;     use std::os::windows::ffi::osstrext;      let raw_input: vec<_> = exe_name.as_os_str().encode_wide().collect();     let raw_extension: vec<_> = osstr::new(".exe").encode_wide().collect();      if raw_input.ends_with(&raw_extension) {         exe_name.into()     } else {         let mut with_exe = exe_name.as_os_str().to_owned();         with_exe.push(".exe");         pathbuf::from(with_exe).into()     } }  // @ top of `find_it` function: // let exe_name = enhance_exe_name(exe_name.as_ref());