9-4.c

《Linux应用开发技术详解》附书光盘中的例程。

#include <stdio.h>
#include <unistd.h>

int main(int argc,char **argv) 
{ 
pid_t my_pid,parent_pid; 
uid_t my_uid,my_euid; 
gid_t my_gid,my_egid; 
struct passwd *my_info; 

my_pid=getpid(); 
parent_pid=getppid(); 
my_uid=getuid(); 
my_euid=geteuid(); 
my_gid=getgid(); 
my_egid=getegid(); 
my_info=getpwuid(my_uid); 

printf("Process ID:%ld\n",my_pid); 
printf("Parent ID:%ld\n",parent_pid); 
printf("User ID:%ld\n",my_uid);
printf("Effective User ID:%ld\n",my_euid);
printf("Group ID:%ld\n",my_gid);
printf("Effective Group ID:%ld\n",my_egid);

if(my_info) 
{ 
printf("My Login Name:%s\n" ,my_info->pw_name); 
printf("My Password :%s\n" ,my_info->pw_passwd); 
printf("My User ID :%ld\n",my_info->pw_uid); 
printf("My Group ID :%ld\n",my_info->pw_gid); 
printf("My Real Name:%s\n" ,my_info->pw_gecos); 
printf("My Home Dir :%s\n", my_info->pw_dir); 
printf("My Work Shell:%s\n", my_info->pw_shell); 
} 
}