$ cargo  nightly -Zscript file.rs

fn main() {}

use std::env;
// https://stackoverflow.com/a/75981598
fn main() {
  let args: Vec<String> = env::args().collect();
  if args.len() > 1 {
      println!("Hello {}!", &args[1]);
  } else {
      println!("Hello world!");
  }
}

$ cargo/bin/cargo  nightly -Zscript ~/bin/script.rs
error: no such command: ` nightly`

	Cargo does not handle ` toolchain` directives.
	Did you mean to invoke `cargo` through `rustup` instead?

#!/bin/sh
//bin/bash -ec '[ "$0" -nt "${0%.*}" ] && /home/user/bin/rustc/bin/rustc -L /home/user/bin/rust-std-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib "$0" -o "${0%.*}"; "${0%.*}" "$@"' "$0" "$@"; exit $?

use std::env;
// https://stackoverflow.com/a/75981598
fn main() {
  let args: Vec<String> = env::args().collect();
  if args.len() > 1 {
      println!("Hello {}!", &args[1]);
  } else {
      println!("Hello world!");
  }
}

//https://stackoverflow.com/q/41322300
//https://c2rust.com/
//https://github.com/rust-lang/rust/issues/1772
#![allow(dead_code, mutable_transmutes, non_camel_case_types, non_snake_case, non_upper_case_globals, unused_assignments, unused_mut)]
#![register_tool(c2rust)]
#![feature(register_tool)]
extern "C" {
    static mut stdin: *mut _IO_FILE;
    static mut stdout: *mut _IO_FILE;
    fn fflush(__stream: *mut FILE) -> libc::c_int;
// ...

./rust.sh "test"
error[E0433]: failed to resolve: use of undeclared crate or module `libc`
  --> ./rust.sh:10:39

// ...

118 |         free(message as *mut libc::c_void);
    |                              ^^^^ use of undeclared crate or module `libc`

error: aborting due to 58 previous errors

For more information about this error, try `rustc --explain E0433`.

cargo 1.82.0-nightly (fa6465836 2024-08-02)
release: 1.82.0-nightly
commit-hash: fa646583675d7c140482bd906145c71b7fb4fc2b
commit-date: 2024-08-02
host: x86_64-unknown-linux-gnu
libgit2: 1.8.1 (sys:0.19.0 vendored)
libcurl: 8.9.0-DEV (sys:0.4.74 curl-8.9.0 vendored ssl:OpenSSL/3.3.1)
ssl: OpenSSL 3.3.1 4 Jun 2024
os: Ubuntu 22.4.0 (jammy) [64-bit]