如何将$ ^ E与数字进行比较？

Question

在/sf/answers/225448191/中,答案表明(之后open)$^E可以与0x20进行比较,以确定另一个进程是否正在使用某个文件:

open ($fh, "<", "the-file");
if ($^E == 0x20) {
  ...
}

我试过了,它的确有效.但是,如果我打印我的值得$^E到一个字符串(The process cannot access the file because it is being used by another process).

那么如何与一个数字进行比较呢？

这是在Windows上.

Answer 1

>perl -E"open my $fh, '<', 'nonexistent'; say 0+$^E; say ''.$^E;"
2
The system cannot find the file specified

就像$!,$^E是一个双变量,一个包含两个值的标量.一个是字符串,一个是数字.

>perl -E"say $^E = 0x20;"
The process cannot access the file because it is being used by another process