C++ and Php and Python language of recommends the way to execute the shell command

In programming, it is often necessary to use the shell command in the program to simplify the program. Record 1 here.

1. C++ execute shell command

#include <iostream>
#include <string>
#include <stdio.h>

int exec_cmd(std::string cmd, std::string &res){
  if (cmd.size() == 0){  //cmd is empty 
    return -1;
  }

  char buffer[1024] = {0};
  std::string result = "";
  FILE *pin = popen(cmd.c_str(), "r");
  if (!pin) { //popen failed 
    return -1;
  }

  res.clear();
  while(!feof(pin)){
    if(fgets(buffer, sizeof(buffer), pin) != NULL){
      result += buffer;
    }
  }

  res = result;
  return pclose(pin); //-1:pclose failed; else shell ret
}

int main(){
  std::string cmd = "ls -ial";
  std::string res;

  std::cout << "ret = " << exec_cmd(cmd, res) << std::endl;
  std::cout << res << std::endl;

  return 0;
}

2. Php executes shell

<?php
  $cmd = "wc -l ./test.php";
  exec($cmd, $output, $code);

  echo $code."\n";
  print_r($output);
?>

3. Python executes shell

import commands

status, output = commands.getstatusoutput('ls -lt')

print status
print output