cmd_lib - Rust command line library

Common rust command line macros and utils, to write shell script like tasks easily in rust programming language. Available at cargo.

run_cmd! --> CmdResult

let name = "rust";
run_cmd!("echo hello, {}", name);

// pipe commands are also supported
run_cmd!("du -ah . | sort -hr | head -n 10");

// also work without string quote
run_cmd!(du -ah . | sort -hr | head -n 10);

// or a group of commands
// if any command fails, just return Err(...)
if run_cmd! {
    use keyword, file;

    cat ${file} | grep ${keyword};
    echo "bad cmd";
    ls -l /nofile;
    date;
}.is_err() {
    warn!("Run group command failed");
}

run_fun! --> FunResult

let version = run_fun!("rustc --version")?;
info!("Your rust version is {}", version.trim());

// with pipes
let n = run_fun!("echo the quick brown fox jumped over the lazy dog | wc -w")?;
info!("There are {} words in above sentence", n.trim());

Run pipe commands in the builder style

parameters could be passed much clearer in this style

Process::new("du -ah .")
    .pipe("sort -hr")
    .pipe("head -n 5")
    .wait::<CmdResult>()?;
// the same run_cmd! macro
run_cmd!("du -ah . | sort -hr | head -n 10")?;

Process::new("ls")
    .pipe("wc -l")
    .current_dir("/src/rust-shell-script/")
    .wait::<CmdResult>()?;

Builtin commands

pwd

pwd: print current working directory

cd

cd: set procecess current directory ``rust run_cmd! { cd /tmp ls | wc -l }; run_cmd!("pwd");

output will be "/tmp"

### lcd
lcd: set group commands current directory
```rust
run_cmd! {
    lcd /tmp
    ls | wc -l
};
run_cmd!("pwd");

output will be the old current directory

Easy Reporting

info!("Running command xxx ...");
warn!("Running command failed");
err!("Copying failed");
die!("Command exit unexpectedly: {}", reason);

output:

INFO: Running command xxx ...
WARN: Running command failed
ERROR: Copying file failed
FATAL: Command exit unexpectedly: disk is full

Complete Example

use cmd_lib::{info, warn, output, run_cmd, run_fun, CmdResult, FunResult};

fn foo() -> CmdResult {
    let dir = "/var/tmp";
    let f = "nofile";

    run_cmd! {
        use dir, f;
        cd ${dir};
        sleep 3;
        ls ${f};
    }
}

fn get_year() -> FunResult {
    let year = run_fun!("date +%Y")?;
    output!("{}", year.trim())
}

fn main() -> CmdResult {
    let name = "rust";
    run_cmd!("echo hello, {}", name)?;

    let result = run_fun!("du -ah . | sort -hr | head -n 5")?;
    info!("Top 5 directories:\n{}", result.trim());

    if foo().is_err() {
        warn!("Failed to run foo()");
    }

    if get_year()? == "2019" {
        info!("You are in year 2019");
    } else {
        info!("Which year are you in ?");
    }

    Ok(())
}