modules/src/system/open.c

   1 /*
   2  * (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands.
   3  * See the copyright notice in the ACK home directory, in the file "Copyright".
   4  */
   5 /* $Id: open.c,v 1.6 1994/06/24 11:24:37 ceriel Exp $ */
   6
   7 #include <system.h>
   8
   9 extern File *_get_entry();
  10
  11 int
  12 sys_open(path, flag, filep)
  13         char *path;
  14         int flag;
  15         File **filep;
  16 {
  17         register int fd;
  18         register File *fp;
  19         long lseek();
  20
  21         if ((fp = _get_entry()) == (File *)0)
  22                 return 0;
  23         switch (flag) {
  24         case OP_READ:
  25                 if ((fd = open(path, 0)) < 0)
  26                         return 0;
  27                 break;
  28         case OP_APPEND:
  29                 if ((fd = open(path, 1)) < 0) {
  30                         if (access(path, 0) == 0)
  31                                 return 0;
  32                 }
  33                 else {
  34                         if (lseek(fd, 0L, 2) < 0L) {
  35                                 close(fd);
  36                                 return 0;
  37                         }
  38                         break;
  39                 }
  40                 /* Fall through */
  41         case OP_WRITE:
  42                 if ((fd = creat(path, 0666)) < 0)
  43                         return 0;
  44                 break;
  45         default:
  46                 return 0;
  47         }
  48         fp->o_flags = flag;
  49         fp->o_fd = fd;
  50         *filep = fp;
  51         return 1;
  52 }