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
|
#include <common.h>
/**
** User function W: exit, sleep, write, getpid, gettime
**
** Reports its presence, then iterates 'n' times printing identifying
** information and sleeping, before exiting.
**
** Invoked as: userW x [ n [ s ] ]
** where x is the ID character
** n is the iteration count (defaults to 20)
** s is the sleep time (defaults to 3 seconds)
*/
USERMAIN(main)
{
int count = 20; // default iteration count
char ch = 'w'; // default character to print
int nap = 3; // nap length
char buf[128];
// process the command-line arguments
switch (argc) {
case 4:
nap = str2int(argv[3], 10);
// FALL THROUGH
case 3:
count = str2int(argv[2], 10);
// FALL THROUGH
case 2:
ch = argv[1][0];
break;
default:
sprint(buf, "userW: argc %d, args: ", argc);
cwrites(buf);
for (int i = 0; i <= argc; ++i) {
sprint(buf, " %s", argv[argc] ? argv[argc] : "(null)");
cwrites(buf);
}
cwrites("\n");
}
// announce our presence
int pid = getpid();
uint32_t now = gettime();
sprint(buf, " %c[%d,%u]", ch, pid, now);
swrites(buf);
write(CHAN_SIO, &ch, 1);
for (int i = 0; i < count; ++i) {
now = gettime();
sprint(buf, " %c[%d,%u] ", ch, pid, now);
swrites(buf);
sleep(SEC_TO_MS(nap));
}
exit(0);
return (42); // shut the compiler up!
}
|
