1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
|
#include <u.h>
#include <libc.h>
int alarmed;
int done;
void
usage(void)
{
fprint(2, "usage: %s [-q]\n", argv0);
exits("usage");
}
void
ding(void*, char *s)
{
if(strstr(s, "alarm")){
alarmed = 1;
noted(NCONT);
} else
noted(NDFLT);
}
void
main(int argc, char **argv)
{
int fd, cfd;
int i;
char buf[1];
int quiet = 0;
ARGBEGIN {
case 'q':
quiet = 1;
break;
} ARGEND;
notify(ding);
fd = open("/dev/cons", ORDWR);
if(fd < 0)
sysfatal("opening /dev/cons: %r");
cfd = open("/dev/consctl", OWRITE);
if(cfd >= 0)
fprint(cfd, "rawon");
switch(rfork(RFPROC|RFFDG|RFMEM)){
case -1:
sysfatal("forking: %r");
default:
// read until we're done writing or
// we get an end of line
while(!done){
alarmed = 0;
alarm(250);
i = read(0, buf, 1);
alarm(0);
if(i == 0)
break;
if(i < 0){
if(alarmed)
continue;
else
break;
}
if(!quiet && write(fd, buf, 1) < 1)
break;
if(buf[0] == '\n' || buf[0] == '\r')
break;
}
break;
case 0:
// pass one character at a time till end of line
for(;;){
if(read(fd, buf, 1) <= 0)
break;
if(write(1, buf, 1) < 0)
break;
if(buf[0] == '\n' || buf[0] == '\r')
break;
}
// tell reader to give up after next char
done = 1;
break;
}
exits(0);
}
|
