com32/lib/fopen.c

   1 /*
   2  * fopen.c
   3  */
   4
   5 #include <stdio.h>
   6 #include <unistd.h>
   7 #include <fcntl.h>
   8
   9 FILE *fopen(const char *file, const char *mode)
  10 {
  11     int flags = O_RDONLY;
  12     int plus = 0;
  13     int fd;
  14
  15     while (*mode) {
  16         switch (*mode) {
  17         case 'r':
  18             flags = O_RDONLY;
  19             break;
  20         case 'w':
  21             flags = O_WRONLY | O_CREAT | O_TRUNC;
  22             break;
  23         case 'a':
  24             flags = O_WRONLY | O_CREAT | O_APPEND;
  25             break;
  26         case '+':
  27             plus = 1;
  28             break;
  29         }
  30         mode++;
  31     }
  32
  33     if (plus) {
  34         flags = (flags & ~(O_RDONLY | O_WRONLY)) | O_RDWR;
  35     }
  36
  37     fd = open(file, flags, 0666);
  38
  39     if (fd < 0)
  40         return NULL;
  41     else
  42         return fdopen(fd, mode);
  43 }