Perl 隐式关闭重置 $.多变的

Question

Perl 的close 的documentation 声明如果您使用open 完成的隐式关闭，$. 不会重置。我试图确切地了解这意味着什么，但无法实现。这是我的脚本：

use strict;
use warnings;
use autodie;
my @files = qw(test1.txt test2.txt test3.txt);

#try with implicit close
for my $file (@files){
    open my $fh, '<', $file;
    while(<$fh>){
        chomp;
        print "line $. is $_\n";
    }
    #implicit close here
}

以下是读入的所有三个文件的内容：

line 1
line 2
line 3
line 4
line 5
line 6
line 7
line 8
line 9
line 10

由于我没有显式调用close，因此应该使用隐式close（我认为）并且不应该重置$.。但是，当我运行脚本时，我得到了这个输出，显示 $.被重置：

line 1 is line 1
line 2 is line 2
line 3 is line 3
line 4 is line 4
line 5 is line 5
line 6 is line 6
line 7 is line 7
line 8 is line 8
line 9 is line 9
line 10 is line 10
line 1 is line 1
line 2 is line 2
line 3 is line 3
line 4 is line 4
line 5 is line 5
line 6 is line 6
line 7 is line 7
line 8 is line 8
line 9 is line 9
line 10 is line 10
line 1 is line 1
line 2 is line 2
line 3 is line 3
line 4 is line 4
line 5 is line 5
line 6 is line 6
line 7 is line 7
line 8 is line 8
line 9 is line 9
line 10 is line 10

它确实看起来像是被我重置了。我对文档的理解是错误的吗？有人可以告诉我在什么情况下隐式close 不会重置$.？

顺便说一句，我使用的是草莓 5.16.1。

Answer 1

$. 实际上不是全局变量，它是最近读取的文件句柄的属性。而且您在循环的每次迭代中都使用了一个新的文件句柄。

像这样修改你的代码“修复”它：

my $fh;
for my $file (@files){
    open $fh, '<', $file;