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

```rust 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

```rust 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 builder style

parameters could be passed much clearer in this style rust 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");

Easy Reporting

rust info!("Running command xxx ..."); warn!("Running command failed"); err!("Copying failed"); die!("Command exit unexpectedly: {}", reason); output: bash INFO: Running command xxx ... WARN: Running command failed ERROR: Copying file failed FATAL: Command exit unexpectedly: disk is full

Complete Example

```rust use cmdlib::{info, warn, output, runcmd, run_fun, CmdResult, FunResult};

fn foo() -> CmdResult { let f = "/var/tmp/nofile"; run_cmd!{ use f; sleep 3; ls ${f}; } }

fn getyear() -> FunResult { let year = runfun!("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(())

} ```

output: bash INFO: Running "echo hello, rust" ... hello, rust INFO: Running "du -ah . | sort -hr | head -n 5" ... INFO: Top 5 directories: 362M . 360M ./target 216M ./target/debug 131M ./target/debug/incremental 117M ./target/package INFO: Running "sleep 3" ... INFO: Running "ls "/var/tmp/nofile"" ... ls: cannot access '/var/tmp/nofile': No such file or directory WARN: Failed to run foo() INFO: Running "date +%Y" ... INFO: You are in year 2019