crates/command-fds/README.md

# command-fds

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A library for passing arbitrary file descriptors when spawning child processes.

## Example

```rust
use command_fds::{CommandFdExt, FdMapping};
use std::fs::File;
use std::os::unix::io::AsRawFd;
use std::process::Command;

// Open a file.
let file = File::open("Cargo.toml").unwrap();

// Prepare to run `ls -l /proc/self/fd` with some FDs mapped.
let mut command = Command::new("ls");
command.arg("-l").arg("/proc/self/fd");
command
    .fd_mappings(vec![
        // Map `file` as FD 3 in the child process.
        FdMapping {
            parent_fd: file.as_raw_fd(),
            child_fd: 3,
        },
        // Map this process's stdin as FD 5 in the child process.
        FdMapping {
            parent_fd: 0,
            child_fd: 5,
        },
    ])
    .unwrap();

// Spawn the child process.
let mut child = command.spawn().unwrap();
child.wait().unwrap();
```

## License

Licensed under the [Apache License, Version 2.0](http://www.apache.org/licenses/LICENSE-2.0).

## Contributing

If you want to contribute to the project, see details of
[how we accept contributions](CONTRIBUTING.md).