实例8-12.c

Linux下C语言编程例子

#include <sys/types.h>
#include <unistd.h> 
#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
extern int errno;
int main()
{
int fd;
printf("This process's uid = %d, euid = %d ",getuid(),geteuid());
if ((fd = open("ping.s",O_RDONLY))==-1)
{
printf("Open error, errno is %d ",errno);
exit(1);
}
Else