add a macro rule system!

[electricface]

macro_rules! system(
    ( $cmd:expr ) => (
        {
            let config = ::std::io::ProcessConfig {
                program: $cmd,
                args: &[],
                stdin: ::std::io::process::InheritFd(0),
                stdout: ::std::io::process::InheritFd(1),
                stderr: ::std::io::process::InheritFd(2),
                .. ::std::io::ProcessConfig::new()
            };

            let mut pro = match ::std::io::Process::configure(config){
                Ok(o) => o,
                Err(e) => fail!("failed to execute process: {} [{}]", $cmd ,e)
            };
            pro.wait()
        }
    );

    ( $cmd:expr,$($args:expr)* ) => (
        {
            let config = ::std::io::ProcessConfig {
                program: $cmd,
                args: &[$($args)*],
                stdin: ::std::io::process::InheritFd(0),
                stdout: ::std::io::process::InheritFd(1),
                stderr: ::std::io::process::InheritFd(2),
                .. ::std::io::ProcessConfig::new()
            };

            let mut pro = match ::std::io::Process::configure(config){
                Ok(o) => o,
                Err(e) => fail!("failed to execute process: {} [{}]", $cmd ,e)
            };
            pro.wait()
        }
    )
)

like the perl 's "system" function.

fn main(){
    let ret = system!("bc",);
    println!("{}" , ret );
}

[lifthrasiir]

As with your other issues, I think you need some rationales to suggest those macros. And I guess it is a better fit for the function (std::io::process::run_process perhaps).

[alexcrichton]

Rust's libraries greatly favor composition over specific functions such as this. As with your other issues about new macros, these are mostly conveniences and don't particularly serve any fundamental purpose.

The existing macros in libstd/macros.rs should all exist because of a fundamental reason. For example, format! could never be a library function because it takes a variable number of arguments on which is has special constraints. The macros you have proposed often do not have a fundamental reason to be macros, and would work well with simple functions instead.

For this reason, I'm going to close this and the associated issues about macros. Issues can be created about adding convenience functions if you like, but I do not believe that this functionality belongs in macros.

[electricface]

i think if you add these macro to std lib ,maybe programmers can use rust like a scripting languages.

[lifthrasiir]

@electricface Rust itself is not designed as a scripting language though. How about making your own macro library (see #11151) to provide additional macros like these?