如何调用外部程序并处理其输出？

import subprocess

# 调用外部程序
result = subprocess.run(['ls', '-l'], capture_output=True, text=True)

# 处理标准输出
print("Standard Output:")
print(result.stdout)

# 处理标准错误
print("Standard Error:")
print(result.stderr)

import java.io.BufferedReader;
import java.io.InputStreamReader;

public class ExternalProcessExample {
    public static void main(String[] args) {
        try {
            ProcessBuilder pb = new ProcessBuilder("ls", "-l");
            Process process = pb.start();

            BufferedReader reader = new BufferedReader(new InputStreamReader(process.getInputStream()));
            String line;
            while ((line = reader.readLine()) != null) {
                System.out.println(line);
            }

            int exitCode = process.waitFor();
            System.out.println("Exit Code: " + exitCode);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

const { exec } = require('child_process');

exec('ls -l', (error, stdout, stderr) => {
    if (error) {
        console.error(`Error: ${error.message}`);
        return;
    }
    if (stderr) {
        console.error(`Stderr: ${stderr}`);
        return;
    }
    console.log(`Stdout: ${stdout}`);
});

#include <iostream>
#include <cstdio>

int main() {
    FILE* pipe = popen("ls -l", "r");
    if (!pipe) {
        return -1;
    }

    char buffer[128];
    while (!feof(pipe)) {
        if (fgets(buffer, 128, pipe) != nullptr) {
            std::cout << buffer;
        }
    }

    pclose(pipe);
    return 0;
}