1、相关函数

#include<unistd.h>
#include<sys/types.h>
pid_t getpid(void);			获得当前进程ID
uid_t getuid(void);			获得当前进程的实际用户ID
uit_t geteuid(void);		获得当前进程的有效用户ID
git_t getgid(void);			获得当前进程的用户组ID
pit_t getppid(void);		获得当前进程的父进程ID
pit_t getpgid(void);		获得当前进程所在的进程组ID
pit_t getpgid(pid_t pid);	获得进程ID为pid的进程所在的进程组ID

2、使用示例

#include<unistd.h>
#include<stdio.h>int main(void)
{printf("pid:%d\n",getpid());printf("ppid:%d\n",getpid());printf("uid:%d\n",getuid());printf("euid:%d\n",geteuid());printf("user gid:%d\n",getgid());printf("gid:%d\n",getpgrp());printf("pgid:%d\n",getpgid(getpid()));printf("ppgid:%d\n",getpgid(getppid()));return 0;
}

运行结果：