将创建进程的API-posix_spawn封装成一个进程类

将创建进程的API封装成一个进程类，用该类生成一个对象，则创建了一个进程；

主要API函数为：

#include <spawn.h>
int posix_spawn(pid_t *restrict pid, const char *restrict path,
const posix_spawn_file_actions_t *file_actions,
const posix_spawnattr_t *restrict attrp,
char *const argv[restrict], char *const envp[restrict]);
#include <sys/types.h>
#include <sys/wait.h>
pid_t wait(int *status);

#include <spawn.h>

int posix_spawn_file_actions_destroy(posix_spawn_file_actions_t *
file_actions);
int posix_spawn_file_actions_init(posix_spawn_file_actions_t *
file_actions);

#include <spawn.h>

int posix_spawnattr_destroy(posix_spawnattr_t *attr);
int posix_spawnattr_init(posix_spawnattr_t *attr);

MyProcess.h

/*************************************************************************
> File Name: MyProcess.h
> Author:
> Mail:
> Created Time: 2015年12月14日 星期一 20时13分03秒
************************************************************************/

#ifndef _MYPROCESS_H
#define _MYPROCESS_H
#include <iostream>
#include <spawn.h>
#include <string>
#include <sys/wait.h>

using std::string;

class MyProcess{
public:
MyProcess(string path, char **av, char **ep);
MyProcess(string path, char **av, char **ep, posix_spawn_file_actions_t psfa, posix_spawnattr_t attr);
void run();
void pwait(int *x);
private:
pid_t pid;
posix_spawn_file_actions_t file_actions;
posix_spawnattr_t attrp;
char **argv;
char **envp;
string ProgramPath;
};
#endif

MyProcess.cpp

/*************************************************************************
> File Name: MyProcess.cpp
> Author:
> Mail:
> Created Time: 2015年12月14日 星期一 20时19分58秒
************************************************************************/

#include "MyProcess.h"
using namespace std;

MyProcess::MyProcess(string path, char **av, char **ep)
{
ProgramPath = path;
argv = av;
envp = ep;
posix_spawn_file_actions_init(&file_actions);
posix_spawnattr_init(&attrp);
}

MyProcess::MyProcess(string path, char **av, char **ep, posix_spawn_file_actions_t psfa, posix_spawnattr_t attr)
{
ProgramPath = path;
argv = av;
envp = ep;
file_actions = psfa;
attrp = attr;

posix_spawn_file_actions_init(&file_actions);
posix_spawnattr_init(&attrp);
}

void MyProcess::run()
{
posix_spawn(&pid, ProgramPath.c_str(), &file_actions, &attrp, argv, envp);
}

void MyProcess::pwait(int *x)
{
wait(x);
}

main.cpp

/*************************************************************************
> File Name: main.cpp
> Author:
> Mail:
> Created Time: 2015年12月14日 星期一 20时04分46秒
************************************************************************/

#include "MyProcess.h"
#include <cstdlib>
using namespace std;

#define PROCESSNUM 2

int main(int argc, char *argv[])
{
int wait_val[2];

if (argc < 2){
cout << "the argc is less than 3" << endl;
exit(-1);
}

MyProcess child1("ls", argv, NULL);
MyProcess child2("/bin/ps", argv, NULL);

child1.run();
child2.run();

child1.pwait(&wait_val[0]);
child1.pwait(&wait_val[1]);

cout << "child1.pwait is " << wait_val[0] << endl;
cout << "child2.pwait is " << wait_val[1] << endl;

exit(0);
}

下图才是程序的运行结果：（将下面的运行结果与上图比较，证明程序正确）