Note: this is a demo for the corresponding
RFC.
Devitions from the RFC include:
- Not as many compilation flags (e.g. --profile)
- -Zpolyfill flags like --test to demo how cargo test might work
- Assuming a "shell" script is actually a parameter from cargo and dropping it
- Implementation: Writing an explicit Cargo.toml in the target dir since
cargo does not understand embedded manifests yet
Run cargo scripts without any setup or explicit compilation step, with seamless use of crates specified as dependencies inside the scripts.
```console $ cargo install cargo-script-mvs [...]
$ cat script.rs
//! Dependencies can be specified in the script file itself as follows:
//!
//! cargo
//! [dependencies]
//! rand = "0.8.0"
//!
use rand::prelude::*;
fn main() { let x: u64 = random(); println!("A random number: {}", x); }
$ ./script.rs A random number: 9240261453149857564 ```
With cargo-eval Rust files and expressions can be executed just like a shell or Python script. Features include:
You can get an overview of the available options using the --help flag.
Install or update cargo-eval using Cargo:
console
$ cargo install cargo-script-mvs
The primary use for cargo-eval is for running Rust source files as scripts. For example:
console
$ echo 'fn main() {println!("Hello, World!");}' > hello.rs
$ cargo-eval hello.rs
Hello, World!
This is the equivalent of:
console
$ mkdir src
$ echo 'fn main() {println!("Hello, World!");}' > src/hello.rs
$ echo '[package]' > Cargo.toml
$ echo 'name = "hello"' >> Cargo.toml
$ echo 'version = "0.0.0"' >> Cargo.toml
$ cargo run --quiet
To show the compilation output, pass --verbose.
cargo-eval will look for embedded dependency and manifest information in the
script as shown by the below now.rs variants:
```rust
//! This is a regular crate doc comment, but it also contains a partial
//! Cargo manifest. Note the use of a fenced code block, and the
//! cargo "language".
//!
//! cargo
//! [dependencies]
//! time = "0.1.25"
//!
fn main() { println!("{}", time::now().rfc822z()); } ```
On Unix systems, you can use #!/usr/bin/env cargo-eval as a shebang line in
a Rust script. This will allow you to execute a script files (which don't need
to have the .rs file extension) directly.
Licensed under either of
at your option.