Question

这个优秀的问题 How to read to and write from a pipe in Perl? 提供了一个很好的答案。

它不适用于ActiveState Perl。

perlfork的BUGS部分 http://docs.activestate.com/activeperl/5.14/lib/pods/perlfork.html 说

在某些情况下，由pipe（），socket（）和accept（）运算符创建的OS级句柄在伪过程中显然没有准确复制。这只发生在某些情况下，但它确实发生的地方，可能会导致管道读写端的死锁处理或无法跨套接字句柄发送或接收数据。

目前尚不清楚“没有准确复制”的含义，或者在这种情况下是否适用。

这是测试程序

#! /usr/bin/env perl

use strict;
use warnings;

my $isActiveStatePerl = 1 ;  # defined(&Win32::BuildNumber);

sub pipeFromFork
{
    return open($_[0], "-|") if (!$isActiveStatePerl);
    pipe $_[0], my $child or die "cannot create pipe";

    printf STDERR "$$: pipe create parent %d child %d\n", fileno($_[0]), fileno($child);
    my $pid = fork();
    die "fork failed: $!" unless defined $pid;
    if ($pid) {         # parent
        printf STDERR "$$: fork parent close child %d\n", fileno($child);
        close $child;
    } else {            # child 
        open(STDOUT, ">&=", $child) or die "cannot clone child to STDOUT";
        printf STDERR "$$: fork child close parent %d stdout %d\n", fileno($_[0]), fileno(STDOUT);
        close $_[0];
    }
    return $pid;
}


my @transform = qw( tr [A-Za-z] [N-ZA-Mn-za-m] );  # rot13
my @inception = (
  "V xabj, Qnq. Lbh jrer qvfnccbvagrq gung V pbhyqa'g or lbh.",
  "V jnf qvfnccbvagrq gung lbh gevrq.",
);

sub snow_fortress { print STDERR "$$: 1 start\n"; print map "$_\n", @inception }

sub hotel 
{
    printf STDERR "$$: 2 start %d\n", fileno(STDIN);
    # my $pid = open STDIN, "-|";
    my $fh;
    my $pid = pipeFromFork($fh);
    print STDERR "$$: hotel: pid $pid\n";
    defined($pid)  or die "$0: fork: $!";
    if (0 == $pid) {
        snow_fortress;
        print STDERR "$$: 1 exit\n";
        exit(0);
    }
    open(STDIN, "<&", $fh)  or die "cannot clone to STDIN";
    printf STDERR "$$: 2 exec %d\n", fileno(STDIN);
    # print while <STDIN>;
    exec @transform or die "$0: exec: $!";
}

# my $pid = open my $fh, "-|";
my $pid = pipeFromFork(my $fh);
defined($pid) or die "$0: fork: $!";
print STDERR "$$: outer: pid $pid\n";

if (0 == $pid) {
    hotel;
    print STDERR "$$: 2 exit\n";
    exit(0);
}

print STDERR "$$: 3  start " . fileno($fh) . "x\n";

print while <$fh>;
print STDERR "$$: 3  end\n";
close $fh or warn "$0: close: $!";

Answer 1

选项1

- 如果您的输入perl过程非常简单，可以放入单行

 my $cmd = "perl -e ' -- your simple perl -- ' | cmdToExecute";

 my $out;
 open my $cmdpipe "-|", $cmd;
 while (<$cmdpipe>) {
    $out .= $_;
 }

 # $out is your captured output

- 如果您的输入perl进程很复杂，请将其放入文件

 my $cmd = "perl compInput.pl | cmdToExecute";
 # rest as above

选项2

- remove ActiveState perl
- install git for windows and use the perl from it.

如何使用ActiveState Perl读取和写入perl中的管道？

1 个答案: