我将尝试将几个perl程序连接在一起,从我所读的内容来看,管道程序应该同时打开和运行。但是,无论我做什么都似乎并非如此。这里是简化版本:
我尝试了两种方式执行它,但结果都相同:
视频程序的时间戳按照应有的顺序递增,但控制程序接收到它们的时间是相同的(在视频程序结束后)。我该如何让控制器在数据生成时即时接收数据而非事后接收?
./video
#!/usr/bin/env perl
my $i = 0;
while($i<10){
my $time = localtime(time);
print "VID: $time $i\n";
sleep 1;
$i++;
}
./controller
#!/usr/bin/env perl
while(my $line = <STDIN>){
my $time = localtime(time);
print "CTRL: $time $line";
}
./pipes
#!/usr/bin/env perl
open(my $controller, "|./controller") || die "Can't fork: $!";
open(STDOUT, ">&", $controller);
open(my $video, "|./video") || die "Can't fork: $!";
print STDERR "All processes started\n";
我尝试了两种方式执行它,但结果都相同:
<16:34:21> rswhiting@Minas-Tirith:~/code/Pipes $ ./pipes
All processes started
CTRL: Sun Apr 20 16:34:32 2014 VID: Sun Apr 20 16:34:22 2014 0
CTRL: Sun Apr 20 16:34:32 2014 VID: Sun Apr 20 16:34:23 2014 1
CTRL: Sun Apr 20 16:34:32 2014 VID: Sun Apr 20 16:34:24 2014 2
CTRL: Sun Apr 20 16:34:32 2014 VID: Sun Apr 20 16:34:25 2014 3
CTRL: Sun Apr 20 16:34:32 2014 VID: Sun Apr 20 16:34:26 2014 4
CTRL: Sun Apr 20 16:34:32 2014 VID: Sun Apr 20 16:34:27 2014 5
CTRL: Sun Apr 20 16:34:32 2014 VID: Sun Apr 20 16:34:28 2014 6
CTRL: Sun Apr 20 16:34:32 2014 VID: Sun Apr 20 16:34:29 2014 7
CTRL: Sun Apr 20 16:34:32 2014 VID: Sun Apr 20 16:34:30 2014 8
CTRL: Sun Apr 20 16:34:32 2014 VID: Sun Apr 20 16:34:31 2014 9
<16:34:49> rob@Minas-Tirith:~/code/Pipes $ ./video | ./controller
CTRL: Sun Apr 20 16:35:25 2014 VID: Sun Apr 20 16:35:15 2014 0
CTRL: Sun Apr 20 16:35:25 2014 VID: Sun Apr 20 16:35:16 2014 1
CTRL: Sun Apr 20 16:35:25 2014 VID: Sun Apr 20 16:35:17 2014 2
CTRL: Sun Apr 20 16:35:25 2014 VID: Sun Apr 20 16:35:18 2014 3
CTRL: Sun Apr 20 16:35:25 2014 VID: Sun Apr 20 16:35:19 2014 4
CTRL: Sun Apr 20 16:35:25 2014 VID: Sun Apr 20 16:35:20 2014 5
CTRL: Sun Apr 20 16:35:25 2014 VID: Sun Apr 20 16:35:21 2014 6
CTRL: Sun Apr 20 16:35:25 2014 VID: Sun Apr 20 16:35:22 2014 7
CTRL: Sun Apr 20 16:35:25 2014 VID: Sun Apr 20 16:35:23 2014 8
CTRL: Sun Apr 20 16:35:25 2014 VID: Sun Apr 20 16:35:24 2014 9
<16:35:25> rob@Minas-Tirith:~/code/Pipes $
视频程序的时间戳按照应有的顺序递增,但控制程序接收到它们的时间是相同的(在视频程序结束后)。我该如何让控制器在数据生成时即时接收数据而非事后接收?
exec "./video"
而不是打开视频作为句柄。 - RobWcout.flush()
即可。不需要欺骗它并告诉它它是更大程序的一部分 :) - RobW