access.c

来自「操作系统实验,文件系统,c语言实现的」· C语言 代码 · 共 73 行

#include <stdio.h>

#include "filesys.h"

unsigned int access(user_id,inode,mode)

unsigned int user_id;

struct inode *inode;

unsigned short mode;

{

   switch(mode)

   {

   case READ:

       if(inode->di_mode & ODIREAD) return 1;

      if((inode->di_mode & GDIREAD) && 

                            (user[user_id].u_gid==inode->di_gid)) return 1;   

        if((inode->di_mode & UDIREAD) && 

                            (user[user_id].u_uid==inode->di_uid)) return 1;

       return 0;

   case WRITE:

       if(inode->di_mode & ODIWRITE)  return 1;

       if((inode->di_mode & GDIWRITE)&&            

            (user[user_id].u_gid==inode->di_gid)) return 1;   

       if((inode->di_mode & UDIWRITE)&&

            (user[user_id].u_uid==inode->di_uid)) return 1;

       return 0;

   case EXICUTE:

       if(inode->di_mode & ODIEXICUTE) return 1;

       if((inode->di_mode & GDIEXICUTE)&&   

            (user[user_id].u_gid==inode->di_gid)) return 1;

       if((inode->di_mode & UDIEXICUTE)&&   

            (user[user_id].u_uid==inode->di_uid)) return 1;

       return 0;

   case DEFAULTMODE:

       return 1;

   defualt:

       return 0;

    }

 }