Execute a system command

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"

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)