64 lines
3.0 KiB
Rust
64 lines
3.0 KiB
Rust
//! This crate contains a single public function
|
|
//! [`get_path_for_executable`](fn.get_path_for_executable.html).
|
|
//! See docs there for more information.
|
|
|
|
use anyhow::{Error, Result};
|
|
use std::env;
|
|
use std::path::Path;
|
|
use std::process::Command;
|
|
|
|
/// Return a `String` to use for the given executable.
|
|
///
|
|
/// E.g., `get_path_for_executable("cargo")` may return just `cargo` if that
|
|
/// gives a valid Cargo executable; or it may return a full path to a valid
|
|
/// Cargo.
|
|
pub fn get_path_for_executable(executable_name: impl AsRef<str>) -> Result<String> {
|
|
// The current implementation checks three places for an executable to use:
|
|
// 1) Appropriate environment variable (erroring if this is set but not a usable executable)
|
|
// example: for cargo, this checks $CARGO environment variable; for rustc, $RUSTC; etc
|
|
// 2) `<executable_name>`
|
|
// example: for cargo, this tries just `cargo`, which will succeed if `cargo` is on the $PATH
|
|
// 3) `~/.cargo/bin/<executable_name>`
|
|
// example: for cargo, this tries ~/.cargo/bin/cargo
|
|
// It seems that this is a reasonable place to try for cargo, rustc, and rustup
|
|
let executable_name = executable_name.as_ref();
|
|
let env_var = executable_name.to_ascii_uppercase();
|
|
if let Ok(path) = env::var(&env_var) {
|
|
if is_valid_executable(&path) {
|
|
Ok(path)
|
|
} else {
|
|
Err(Error::msg(format!(
|
|
"`{}` environment variable points to something that's not a valid executable",
|
|
env_var
|
|
)))
|
|
}
|
|
} else {
|
|
if is_valid_executable(executable_name) {
|
|
return Ok(executable_name.to_owned());
|
|
}
|
|
if let Some(mut path) = dirs::home_dir() {
|
|
path.push(".cargo");
|
|
path.push("bin");
|
|
path.push(executable_name);
|
|
if is_valid_executable(&path) {
|
|
return Ok(path.into_os_string().into_string().expect("Invalid Unicode in path"));
|
|
}
|
|
}
|
|
// This error message may also be caused by $PATH or $CARGO/$RUSTC/etc not being set correctly
|
|
// for VSCode, even if they are set correctly in a terminal.
|
|
// On macOS in particular, launching VSCode from terminal with `code <dirname>` causes VSCode
|
|
// to inherit environment variables including $PATH, $CARGO, $RUSTC, etc from that terminal;
|
|
// but launching VSCode from Dock does not inherit environment variables from a terminal.
|
|
// For more discussion, see #3118.
|
|
Err(Error::msg(format!("Failed to find `{}` executable. Make sure `{}` is in `$PATH`, or set `${}` to point to a valid executable.", executable_name, executable_name, env_var)))
|
|
}
|
|
}
|
|
|
|
/// Does the given `Path` point to a usable executable?
|
|
///
|
|
/// (assumes the executable takes a `--version` switch and writes to stdout,
|
|
/// which is true for `cargo`, `rustc`, and `rustup`)
|
|
fn is_valid_executable(p: impl AsRef<Path>) -> bool {
|
|
Command::new(p.as_ref()).arg("--version").output().is_ok()
|
|
}
|