windows - 为什么此路径无法在 PERL 中打开 Windows 文件？

Question

我尝试使用 Strawberry Perl，但让我感到困惑的其中一件事是阅读文件。

我尝试过:

open(FH, "D:\test\numbers.txt");

但是它找不到文件(尽管文件在那里，并且没有权限问题)。

等效代码(除文件名外，脚本 100% 相同)在 Linux 上运行良好。

Answer 1

根据 Perl FAQ 5 ，您应该在 DOS/Windows 文件名中使用正斜杠(或者，作为替代方案，转义反斜杠)。

Why can't I use "C:\temp\foo" in DOS paths? Why doesn't `C:\temp\foo.exe` work?

Whoops! You just put a tab and a formfeed into that filename! Remember that within double quoted strings ("like\this"), the backslash is an escape character. The full list of these is in Quote and Quote-like Operators in perlop. Unsurprisingly, you don't have a file called "c:(tab)emp(formfeed)oo" or "c:(tab)emp(formfeed)oo.exe" on your legacy DOS filesystem.

Either single-quote your strings, or (preferably) use forward slashes. Since all DOS and Windows versions since something like MS-DOS 2.0 or so have treated / and \ the same in a path, you might as well use the one that doesn't clash with Perl--or the POSIX shell, ANSI C and C++, awk, Tcl, Java, or Python, just to mention a few. POSIX paths are more portable, too.

所以你的代码应该是 open(FH, "D:/test/numbers.txt"); 而不是试图打开一个名为 "D:est\numbers .txt”

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顺便说一句，您可以通过使用词法(而不是全局命名)文件句柄、open 的 3 参数形式来进一步改进您的代码，最重要的是，对所有 IO 操作进行错误检查，尤其是 open () 调用:

open(my $fh, "<", "D:/test/numbers.txt") or die "Could not open file: $!";

或者，更好的是，不要在 IO 调用中对文件名进行硬编码(以下做法可能会让您更快地找出问题):

my $filename = "D:/test/numbers.txt";
open(my $fh, "<", $filename) or die "Could not open file $filename: $!";