[linux操作系统实验]进程的控制(execl()第二个传参为什么是可执行程序名)

/ 1评论 / 582阅读 / 0点赞

问题

实验示例代码中,调用execl()时,第二个传参为什么会是可执行程序名:

execl("/bin/ls", "ls", "-l", "-color", NULL)

#include <iostream>
using namespace std;

int main(int aNum, char** aStr)
{
        cout << "hello,coolight" << endl;
        cout << "main参数列表:" << endl;
        for(int i = 0; i < aNum; ++i)
                cout << i + 1 << " : " << aStr[i] << endl;

        return 0;
}

实验具体内容

实验内容

涉及的系统调用

在Linux中fork()是一个非常有用的系统调用,但在Linux中建立进程除了fork()之外,也可用与fork() 配合使用的exec()。

exec()系列

exec()fork()联合使用

int status;
     ............
if (fork() == 0)
{
     ............
     execl(...);
     ............
}
wait(&status);

wait()

exit()

源代码

#include <iostream>
#include <unistd.h>
#include "sys/wait.h"
#include "sys/types.h"
using namespace std;
int main()
{
        cout << "<< coolgiht" << endl;
        int status, renum_fork = fork();
        if(renum_fork == -1){
                cout << "<< fork error!" << endl;
        }else if(renum_fork == 0){ //子进程
                execl("./hello", "hello", "-1", "-2", NULL);
                cout << "execl error!" << endl;
        }else{  //父进程
                wait(NULL);
                cout << "<< 完成!" << endl;
        }
        return 0;
}
#include <iostream>
using namespace std;
int main(int aNum, char** aStr)
{
        cout << "hello,coolight" << endl;
        cout << "main参数列表:" << endl;
        for(int i = 0; i < aNum; ++i)

                cout << i + 1 << " : " << aStr[i] << endl;

        return 0;
}

运行结果截图

思考

  1. grenuenah说道:

    A slick Syriac staffed factory even harvests the produce of Syriac vineyards, making Syriac wines for sale in the restaurants of the new boutique hotels in the historic towns of Mardin and Midyat generic cialis cost Given that previous descriptions of nociceptor structure have not allowed for systematic comparisons between body regions, we sought to use sparse genetic labeling to trace single nociceptor morphologies across the entire somatotopic map

发表回复

您的电子邮箱地址不会被公开。 必填项已用*标注