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# which
A Rust equivalent of Unix command "which". Locate installed executable in cross platforms.
## Support platforms
* Linux
* Windows
* macOS
* wasm32-wasi*
### A note on WebAssembly
This project aims to support WebAssembly with the [WASI](https://wasi.dev/) extension. All `wasm32-wasi*` targets are officially supported.
If you need to add a conditional dependency on `which` please refer to [the relevant cargo documentation for platform specific dependencies.](https://doc.rust-lang.org/cargo/reference/specifying-dependencies.html#platform-specific-dependencies)
Here's an example of how to conditionally add `which`. You should tweak this to your needs.
```toml
[target.'cfg(not(all(target_family = "wasm", target_os = "unknown")))'.dependencies]
which = "7.0.0"
```
Note that non-WASI environments have no access to the system. Using this in that situation requires disabling the default features of this crate and providing a custom `which::sys::Sys` implementation to `which::WhichConfig`.
## Examples
1) To find which rustc executable binary is using.
``` rust
use which::which;
let result = which("rustc").unwrap();
assert_eq!(result, PathBuf::from("/usr/bin/rustc"));
```
2. After enabling the `regex` feature, find all cargo subcommand executables on the path:
``` rust
use which::which_re;
which_re(Regex::new("^cargo-.*").unwrap()).unwrap()
.for_each(|pth| println!("{}", pth.to_string_lossy()));
```
## MSRV
This crate currently has an MSRV of Rust 1.70. Increasing the MSRV is considered a breaking change and thus requires a major version bump.
We cannot make any guarantees about the MSRV of our dependencies. You may be required to pin one of our dependencies to a lower version in your own Cargo.toml in order to compile
with the minimum supported Rust version. Eventually Cargo will handle this automatically. See [rust-lang/cargo#9930](https://github.com/rust-lang/cargo/issues/9930) for more.
## Documentation
The documentation is [available online](https://docs.rs/which/).