This is a small crate that lets you build pipe chains between spawned processes using a syntax similar to the Unix shell.
```rust
use ubend::IntoPipeSetup;
let output = spawn!( cat <"./tests/input.txt" | grep "spam" | wc "-l" ).expect("spawn failed"). output(). expect("reading output failed"). stdout;
let output = String::from_utf8(output).
expect("UTF-8 error").
trim().
parse::
println!("output: {}", output); ```
Note that arguments to commands need always to be quoted. If you don't quote
them they are interpreted as Rust identifiers which allows you to pass
dynamic strings. Also FOO="bar" cat <"baz"
is the same as
FOO = "bar" cat < "baz"
, since whitespace is ignored in Rust.
use ubend::IntoPipeSetup
is needed when passing a file name or
std::fs::File
as redirection source/target.
Note: Currently only Linux ist tested. Other Unix operating systems might work, too. Windows support is not implemented.
```rust
use ubend::IntoPipeSetup; use ubend::PipeSetup::*;
use std::fs::File; use std::io::{Read, Seek, SeekFrom};
// Ignore stderr spawn!(rm "nosuchfile" 2>Null);
// Redirect stderr to stdout spawn!(rm "nosuchfile" 2>&1);
// Write stderr to stderr of this process spawn!(rm "nosuchfile" 2>Inherit);
// Read from a file opened in Rust
let file = File::open("./tests/input.txt").
expect("couldn't open file");
spawn!(grep "spam" // Write stderr to a temp file
let mut chain = spawn!(rm "nosuchfile" 2>Temp).
expect("spawn failed"); chain.wait_last().
expect("wait failed"); let mut temp = chain.stderr().unwrap(); // Since the file descriptor was shared with the spawned process the
// position needs to be reset manually:
temp.seek(SeekFrom::Start(0)).
expect("seek failed");
```