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add EOF handling to console_read - works with cat

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rsc 2007-08-08 08:04:02 +00:00
parent ca3d577671
commit 07018064bb
1 changed files with 18 additions and 13 deletions
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27
console.c
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@ -316,7 +316,7 @@ static uchar *charcode[4] = {
}; };
#define KBD_BUF 64 #define KBD_BUF 64
char kbd_buf[KBD_BUF]; uchar kbd_buf[KBD_BUF];
int kbd_r; int kbd_r;
int kbd_w; int kbd_w;
struct spinlock kbd_lock; struct spinlock kbd_lock;
@ -389,24 +389,29 @@ out:
int int
console_read(int minor, char *dst, int n) console_read(int minor, char *dst, int n)
{ {
uint target = n; uint target;
int c;
target = n;
acquire(&kbd_lock); acquire(&kbd_lock);
while(n > 0){
while(kbd_w == kbd_r) { while(kbd_r == kbd_w)
sleep(&kbd_r, &kbd_lock); sleep(&kbd_r, &kbd_lock);
c = kbd_buf[kbd_r++];
if(c == C('D')){ // EOF
if(n < target){
// Save ^D for next time, to make sure
// caller gets a 0-byte result.
kbd_r--;
} }
break;
while(n > 0 && kbd_w != kbd_r){ }
*dst = (kbd_buf[kbd_r]) & 0xff; *dst++ = c;
cons_putc(*dst & 0xff); cons_putc(c);
dst++;
--n; --n;
kbd_r++;
if(kbd_r >= KBD_BUF) if(kbd_r >= KBD_BUF)
kbd_r = 0; kbd_r = 0;
} }
release(&kbd_lock); release(&kbd_lock);
return target - n; return target - n;