Execute a system command

Execute a system command
You are encouraged to solve this task according to the task description, using any language you may know.

In this task, the goal is to run either the ls system command, or the pause system command.

AppleScript

do shell script "ls" without altering line endings

C

Compiler: GCC 4.0.1

Platform: BSD

#include <stdlib.h>

int main()
{
    system("ls");
}

C++

Compiler: Visual C++ 2005

system("pause");

Haskell

Interpreter: GHCi 6.6

import System.Cmd

main = system "ls"

IDL

 $ls

Will execute "ls" with output to the screen.

 spawn,"ls",result

will execute it and store the result in the string array "result".

 spawn,"ls",unit=unit

will execute it asynchronously and direct any output from it into the LUN "unit" from whence it can be read at any (later) time.

Objective-C

Compiler: GCC 4.0.1 (apple)

NSTask runs an external process with explicit path and arguments.

void runls()
{
    [[NSTask launchedTaskWithLaunchPath:@"/bin/ls"
        arguments:[NSArray array]] waitUntilExit];
}

If you need to run a system command, invoke the shell:

void runSystemCommand(NSString *cmd)
{
    [[NSTask launchedTaskWithLaunchPath:@"/bin/sh"
        arguments:[NSArray arrayWithObjects:@"-c", cmd, nil]]
        waitUntilExit];
}

Or use the C method above.

Perl

Note the use of grave quotes instead of "normal" single quotes.

`ls`

UNIX Shell

UNIX shells are designed to run system commands as a default operation.

ls

If one wants to capture the command's standard output:

CAPTUREDOUTPUT=$(ls)