如何从Perl创建然后使用长Windows路径? [英] How do I create then use long Windows paths from Perl?
问题描述
我有一个构建过程的一部分，该过程在Windows中创建了一条长得很长的路径.这不是我的错.它有几个目录，而且目录名称都没有异常长.它们又长又足够多，足以超过MAX_PATH(260个字符).在这些名称中，我没有使用ASCII以外的任何其他字符.
最大的问题是爆炸发生在 Module :: Build 在dist目标期间，尽管我认为构建系统无关紧要，因为它们将创建相同的目录.
使用File::Path创建这些超长目录之一失败:
use File::Path qw( make_path );
make_path( 'C:\\.....' ); # fails if path is over 260 chars
类似地，一旦绝对路径超过了MAX_PATH，手动构建每个目录级别就会失败.
这不是新事物，也不是Perl的错，Microsoft在向ActiveState提交的错误报告，这表明我还有其他问题需要修正以获取Unicode文件名，Jan Dubois在，尽管我不确定它是否适用(并且文件名非常旧). perlrun 提到，这曾经是-C开关的工作，但显然，这部分是弃. perl RT队列中有一个较新的错误 60888:Win32:支持完整文件名中的unicode(使用Wide-system调用).
宫川指出了一些Unicode文件名问题和 Win32API :: File ，而没有特别提及长路径.但是， Win32API :: File CPAN论坛条目似乎仅表示恐惧，这会导致愤怒，导致仇恨等等. Perlmonks 帖子解决方案
进度:
以下脚本有效:将字符串写入路径较长的目录中的文件，并且能够读取相同的字符串. (成功运行不会产生任何控制台输出).我也做了繁琐的工作来覆盖open.
#!/usr/bin/perl
use strict;
use warnings;
use Carp;
use Encode qw( encode );
use Symbol;
use Win32;
use Win32API::File qw(
CreateFileW OsFHandleOpen
FILE_GENERIC_READ FILE_GENERIC_WRITE
OPEN_EXISTING CREATE_ALWAYS FILE_SHARE_READ
);
use Win32::API;
use File::Spec::Functions qw(catfile);
Win32::API->Import(
Kernel32 => qq{BOOL CreateDirectoryW(LPWSTR lpPathNameW, VOID *p)}
);
my %modes = (
'<' => {
access => FILE_GENERIC_READ,
create => OPEN_EXISTING,
mode => 'r',
},
'>' => {
access => FILE_GENERIC_WRITE,
create => CREATE_ALWAYS,
mode => 'w',
},
# and the rest ...
);
use ex::override open => sub(*;$@) {
$_[0] = gensym;
my %mode = %{ $modes{$_[1]} };
my $os_fh = CreateFileW(
encode('UCS-2le', "$_[2]\0"),
$mode{access},
FILE_SHARE_READ,
[],
$mode{create},
0,
[],
) or do {$! = $^E; return };
OsFHandleOpen($_[0], $os_fh, $mode{mode}) or return;
return 1;
};
my $path = '\\\\?\\' . Win32::GetLongPathName($ENV{TEMP});
my @comps = ('0123456789') x 30;
my $dir = mk_long_dir($path, \@comps);
my $file = 'test.txt';
my $str = "This is a test\n";
write_test_file($dir, $file, $str);
$str eq read_test_file($dir, $file) or die "Read failure\n";
sub write_test_file {
my ($dir, $file, $str) = @_,
my $path = catfile $dir, $file;
open my $fh, '>', $path
or croak "Cannot open '$path':$!";
print $fh $str or die "Cannot print: $!";
close $fh or die "Cannot close: $!";
return;
}
sub read_test_file {
my ($dir, $file) = @_,
my $path = catfile $dir, $file;
open my $fh, '<', $path
or croak "Cannot open '$path': $!";
my $contents = do { local $/; <$fh> };
close $fh or die "Cannot close: $!";
return $contents;
}
sub mk_long_dir {
my ($path, $comps) = @_;
for my $comp ( @$comps ) {
$path = catfile $path, $comp;
my $ucs_path = encode('UCS-2le', "$path\0");
CreateDirectoryW($ucs_path, undef)
or croak "Failed to create directory: '$path': $^E";
}
return $path;
}
将Win32::GetANSIPathName()与内置open结合使用不起作用:返回的路径太长.
查看修改历史记录以了解失败的实验.
I have part of a build process that creates a hideously long paths in Windows. It's not my fault. It's several directories deep, and none of the directory names are abnormally long; they're just long and numerous enough to make it over MAX_PATH (260 chars). I'm not using anything other than ASCII in these names.
The big problem is that the blow-up happens deep in the guts of Module::Build during the dist target, although I figure the build system doesn't matter because they'd make the same directories.
Creating one of these overly-long directories with File::Path fails:
use File::Path qw( make_path );
make_path( 'C:\\.....' ); # fails if path is over 260 chars
Similarly, constructing each directory level by hand fails once the absolute path would go over MAX_PATH.
This isn't new, isn't Perl's fault, and Microsoft documents it in Naming Files, Paths, and Namespaces. Their fix suggests adding the \\?\ in front of any path to access the Unicode filename API. However, that doesn't seem to be the full fix for a Perl script because it still fails:
use File::Path qw( make_path );
make_path( '\\\\?\\C:\\.....' ); # still fails if path is over MAX_PATH, works otherwise
This might be because make_path pulls apart its argument and then goes through the directories one level at a time, so \\?\ only applies to the top-level, which is within MAX_PATH.
I dug up a bug report to ActiveState that suggests there's something else I need to fix up to get to the Unicode filenames, and Jan Dubois gives a bit more details in Re: "long" filenames on Windows 2K/XP, although I'm not sure it applies (and is extremely old). perlrun mentions that this use to be the job of the -C switch, but apparently that part was abandoned. The perl RT queue has a more recent bug 60888: Win32: support full unicode in filenames (use Wide-system calls).
Miyagawa notes some Unicode filename issues and Win32API::File without specifically mentioning long paths. However, the Win32API::File CPAN Forum entry seems to indicate only fear, which leads to anger, which leads to hate, and so on. There's an example in the Perlmonks post How to stat a file with a Unicode (UTF16-LE) filename in Windows?. It seems the Win32::CreateDirectory is the answer, and I'll try that the next time I get next to a Windows machine.
Then, supposing I can create the long path path. Now I have to teach Module::Build, and maybe other things, to handle it. That might be immediately easy with monkeypatches if Win32::GetANSIPathName() does what it says on the tin.
Progress:
The following script works: It writes a string to a file in a directory with a long path and it is able to read back the same string. (A successful run produces no console output). I have also made a cumbersome effort to override open.
#!/usr/bin/perl
use strict;
use warnings;
use Carp;
use Encode qw( encode );
use Symbol;
use Win32;
use Win32API::File qw(
CreateFileW OsFHandleOpen
FILE_GENERIC_READ FILE_GENERIC_WRITE
OPEN_EXISTING CREATE_ALWAYS FILE_SHARE_READ
);
use Win32::API;
use File::Spec::Functions qw(catfile);
Win32::API->Import(
Kernel32 => qq{BOOL CreateDirectoryW(LPWSTR lpPathNameW, VOID *p)}
);
my %modes = (
'<' => {
access => FILE_GENERIC_READ,
create => OPEN_EXISTING,
mode => 'r',
},
'>' => {
access => FILE_GENERIC_WRITE,
create => CREATE_ALWAYS,
mode => 'w',
},
# and the rest ...
);
use ex::override open => sub(*;$@) {
$_[0] = gensym;
my %mode = %{ $modes{$_[1]} };
my $os_fh = CreateFileW(
encode('UCS-2le', "$_[2]\0"),
$mode{access},
FILE_SHARE_READ,
[],
$mode{create},
0,
[],
) or do {$! = $^E; return };
OsFHandleOpen($_[0], $os_fh, $mode{mode}) or return;
return 1;
};
my $path = '\\\\?\\' . Win32::GetLongPathName($ENV{TEMP});
my @comps = ('0123456789') x 30;
my $dir = mk_long_dir($path, \@comps);
my $file = 'test.txt';
my $str = "This is a test\n";
write_test_file($dir, $file, $str);
$str eq read_test_file($dir, $file) or die "Read failure\n";
sub write_test_file {
my ($dir, $file, $str) = @_,
my $path = catfile $dir, $file;
open my $fh, '>', $path
or croak "Cannot open '$path':$!";
print $fh $str or die "Cannot print: $!";
close $fh or die "Cannot close: $!";
return;
}
sub read_test_file {
my ($dir, $file) = @_,
my $path = catfile $dir, $file;
open my $fh, '<', $path
or croak "Cannot open '$path': $!";
my $contents = do { local $/; <$fh> };
close $fh or die "Cannot close: $!";
return $contents;
}
sub mk_long_dir {
my ($path, $comps) = @_;
for my $comp ( @$comps ) {
$path = catfile $path, $comp;
my $ucs_path = encode('UCS-2le', "$path\0");
CreateDirectoryW($ucs_path, undef)
or croak "Failed to create directory: '$path': $^E";
}
return $path;
}
Using Win32::GetANSIPathName() with built-in open does not work: The path returned is too long.
See edit history for failed experiments.
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