perl - 在 Perl 中读取 STDIN 上的管道输入后，我可以提示用户输入吗？

Question

我正在尝试编写一个 perl 脚本来读取管道数据，然后根据该数据提示用户输入。以下脚本，prompt_for_action , 是我想要做的:

#!/usr/bin/perl 

my @hosts = ();
while (<>) {
    my $host = $_;
    $host =~ s/\n//; # strip newlines
    push(@hosts, $host);
}

for my $host (@hosts) {
    print "Do you want to do x with $host ? y/n: ";
    chomp(my $answer = <>);
    print "You said `$answer`.\n";
}

但是当我运行它时没有等待用户输入，它只是在不等我输入的情况下运行:

$ echo "test1.example.com
> test2.example.com" | ./prompt_for_action
Do you want to do x with test1.example.com ? y/n: You said ``.
Do you want to do x with test2.example.com ? y/n: You said ``.

如果我不从 STDIN 读取我的数据...

#!/usr/bin/perl 

my @hosts = ('test1.example.com', 'test12.example.com');

for my $host (@hosts) {
    print "Do you want to do x with $host ? y/n: ";
    chomp(my $answer = <>);
    print "You said `$answer`.\n";
}

然后脚本工作正常:

$ ./prompt_for_action 
Do you want to do x with test1.example.com ? y/n: y
You said `y`.
Do you want to do x with test12.example.com ? y/n: n
You said `n`.

管道到 STDIN 然后提示用户输入是否可能？如果是这样怎么办？

Answer 1

在 Unix-y 系统上，您可以打开 /dev/tty用于读取的伪文件。

while (<STDIN>) {
    print "from STDIN: $_";
}
close STDIN;

# oops, need to read something from the console now
open TTY, '<', '/dev/tty';
print "Enter your age: ";
chomp($age = <TTY>);
close TTY;
print "You look good for $age years old.\n";