1 #include <stdio.h>
2 
3 
4 void writestuff (FILE *f)
5 {
6   fprintf (f, "hello world\n");
7   fputc ('y', f);
8   putc ('e', f);
9 }
10 
11 void readstuff (FILE *f)
12 {
13   int c, d;
14   char stuff[100], *s;
15   c = fgetc (f);
16   ungetc (c, f);
17   d = fgetc (f);
18   s = fgets (stuff, sizeof(stuff), f);
19 }
20 
21 int main ()
22 {
23   FILE *f;
24   writestuff (stdout);
25   writestuff (stderr);
26   f = fopen ("/dev/null", "w");
27   writestuff (f);
28   fclose (f);
29   f = fopen ("/dev/zero", "r");
30   readstuff (f);
31   f = freopen ("/dev/null", "w", f);
32   writestuff (f);
33   fclose (f);
34 
35   return 0;
36 }
37