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<>Linux进程基础
<>主要概念:
父进程与子进程
创建新进程的那个进程称为父进程,新进程称为子进程。使用 fork() 函数创建子进程。
<>实验目的:
创建子进程,分别在父进程和子进程中打印各自的 PID。
<>相关函数:
#include <sys/types.h> #include <unistd.h> pid_t fork(void) //创建进程 pid_t getpid
(void) //获取进程ID pid_t getppid(void) //获取父进程ID
<>代码:
//fork.c #include <stdio.h> #include <unistd.h> int main(void) { pid_t pid; pid
= fork(); if(pid < 0) { printf("fork is error \n"); return -1; } if(pid > 0) {
printf("This is parent, parent pid is %d\n", getpid()); } if(pid == 0) { printf(
"This is child, child pid is %d, parent pid is %d\n", getpid(), getppid()); }
return 0; }
<>编译运行:
sixer@ubuntu:~/imx_usr/sys_app/01_process$ gcc -o fork fork.c
sixer@ubuntu:~/imx_usr/sys_app/01_process$ ./fork
<>实验现象:
sixer@ubuntu:~/imx_usr/sys_app/01_process$ ./fork This is parent, parent pid
is 2039 This is child, child pid is 2040, parent pid is 2039
<>总结:
可见父进程PID为2039,父进程创建了PID为2040的子进程。