i386/junos/ucla/src/lab4/kern/printf.c

   1 // Simple implementation of cprintf console output for the kernel,
   2 // based on printfmt() and the kernel console's cputchar().
   3
   4 #include <inc/types.h>
   5 #include <inc/stdio.h>
   6 #include <inc/stdarg.h>
   7
   8
   9 static void
  10 putch(int ch, void *ptr)
  11 {
  12         int *cnt = (int *) ptr;
  13         cputchar(ch);
  14         *cnt++;
  15 }
  16
  17 int
  18 vcprintf(const char *fmt, va_list ap)
  19 {
  20         int cnt = 0;
  21
  22         vprintfmt(&putch, &cnt, fmt, ap);
  23         return cnt;
  24 }
  25
  26 int
  27 cprintf(const char *fmt, ...)
  28 {
  29         va_list ap;
  30         int cnt;
  31
  32         va_start(ap, fmt);
  33         cnt = vcprintf(fmt, ap);
  34         va_end(ap);
  35
  36         return cnt;
  37 }
  38