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
|
#!/usr/bin/perl
eval 'exec /usr/bin/perl -S $0 ${1+"$@"}'
if $running_under_some_shell;
require 'sys/ipc.ph';
require 'sys/shm.ph';
$| = 1;
$mode = shift;
die "usage: ipcshm {r|s}\n" unless $mode =~ /^[rs]$/;
$send = ($mode eq "s");
$SIZE = 32;
$id = shmget(0x1234, $SIZE, ($send ? 0 : &IPC_CREAT) | 0644);
die "Can't get shared memory: $!\n" unless defined($id);
print "shared memory id: $id\n";
if ($send) {
while (<STDIN>) {
chop;
unless (shmwrite($id, pack("La*", length($_), $_), 0, $SIZE)) {
die "Can't write to shared memory: $!\n";
}
}
}
else {
$SIG{'INT'} = $SIG{'QUIT'} = "leave";
for (;;) {
$_ = <STDIN>;
unless (shmread($id, $_, 0, $SIZE)) {
die "Can't read shared memory: $!\n";
}
$len = unpack("L", $_);
$message = substr($_, length(pack("L",0)), $len);
printf "[%d] %s\n", $len, $message;
}
}
&leave;
sub leave {
if (!$send) {
$x = shmctl($id, &IPC_RMID, 0);
if (!defined($x) || $x < 0) {
die "Can't remove shared memory: $!\n";
}
}
exit;
}
|
