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

5777

5778 /*

5779  * creat system call

5780  */

5781 creat()

5782 {

5783     register *ip;

5784     extern uchar;

5785

5786     ip = namei(&uchar, 1);

• ip 指向 文件路径name 对应的 文件inode块

5787     if(ip == NULL) {

5788          if(u.u_error)

5789               return;

5790          ip = maknode(u.u_arg[1]&07777&(~ISVTX));

• 创建INODE，并链入父目录
• 标志位强制清 ISVTX，定义参看inode.h

5791          if (ip==NULL)

5792           return;

5793          open1(ip, FWRITE, 2);

5794     } else

• LIONS源代码原文为

5794 } 疑为笔误

5795     open1(ip, FWRITE, 1);

5796 }

5797 /* ------------------------- */

(creat = 8.)

sys creat; name; mode

(file descriptor in r0)