code:owner - ikarishinjieva/unixV6-code-analyze-chs GitHub Wiki

6782

6783 /*

6784 * Look up a pathname and test if

6785 * the resultant inode is owned by the

6786 * current user.

6787 * If not, try for super-user.

6788 * If permission is granted,

6789 * return inode pointer.

6790 */

6791 owner()

6792 {

6793 register struct inode *ip;

6794 extern uchar();

6795

6796 if ((ip = namei(uchar, 0)) == NULL)

6797 return(NULL);

获取路径名对应的inode,并赋给ip

若获取失败,返回空

6798 if(u.u_uid == ip->i_uid)

6799 return(ip);

如果当前用户为文件拥有者,返回ip

6800 if (suser())

6801 return(ip);

如果当前用户为超级用户,返回ip

6802 iput(ip);

如果当前用户既非文件拥有者又非超级用户,释放ip

6803 return(NULL);

6804 }

6805 /* -------------------------*/