一个创建子进程的简单示例代码

参考APUE中第1章1.6小节

主要涉及到2个函数： fork、exec

 

// filename : process_ctrl.c
// child process -- fork, exec, waitpid

#include <stdio.h>
#include <sys/wait.h>

#define MAXLINE 32


int main(int argc, char *argv[])
{
    char     buf[MAXLINE];
    pid_t     pid;
    int     status;

    printf("parent: pid=%d
", getpid());
    printf("%% ");

    while (fgets(buf, MAXLINE, stdin) != NULL)
    {
        if (buf[strlen(buf) - 1] == '
')
            buf[strlen(buf)-1] = 0;

        pid = fork();

        if (pid < 0)
        {
            printf("parent: fork() error!
");
        }
        else if (pid == 0)
        {
            printf("child: new process start!
");
            printf("child: new process pid=%d
", getpid());
            execlp(buf, buf, (char *)0);
            printf("child: couldn't execure: %s
", buf);
            exit(1);
        }
        else
        {
            printf("parent: child process pid=%d
", pid);
        }

        if ((pid = waitpid(pid, &status, 0)) < 0)
            printf("waitpid error
");
        printf("%%");
    }
}

运行结果：

 

%[mht@localhost p1_5]$ ./process_ctrl
parent: pid=6922
% ls
child: new process start!
child: new process pid=6927
process_ctrl  process_ctrl.c
parent: child process pid=6927
%