From ran@timedia.co.jp

If a directory include <0x5c> as a last byte of a directory name, ActivePerl can't judge whether this directory exists or not in a system by using "-d" (like a following sample code "test.pl").

#!perl
if (-d $ARGV[0]) {
print "$ARGV[0] is directory.\n";
} else {
print "$ARGV[0] is not directory.\n";
}

For example, when there is a directory consists of multi-byte
characters.

C:\<0x94><0x5c>

In Japanese Windows environments, these two bytes (<0x94> and <0x5c>)
compose a Japanese character.

When I ran a sample code "test.pl"(see above):

C:\> test.pl C:\<0x94><0x5c>
C:\<0x94><0x5c> is not directory

it returns "is not directory" even if C:<0x94><0x5c> directory exists in a system.

However, when I added a backslash or backslashes as follows:

C:\> test.pl C:\<0x94><0x5c>\
C:\<0x94><0x5c>\ is directory

C:\> test.pl C:\<0x94><0x5c>\\
C:\<0x94><0x5c>\\ is directory

C:\> test.pl C:\<0x94><0x5c>\\\
C:\<0x94><0x5c>\\\ is directory

a sample program can find C:<0x94><0x5c> directory and returns "is directory".

It seemed that one or more <0x5c> is trancated and it causes a fatal
problem on a Japanese named directory that may include <0x5c> as a
second byte of a particular character.

Once I submitted this problem in a bugtraq in ActiveState and received a following comment:

Comments from Jan Dubois 2004-05-18 07:27

Perl doesn't internally use the Unicode API on Windows, so the low level IO routines assume all filenames are using single byte characters only. The 0x5c character is a backslash '\' and Perl assumes that forward and backward slashes are semantically equivalent.

To work around a bug in the stat() function of the C runtime library Perl modifies a trailing backslash to a forward slash (in the win32_stat() function in win32.c).

I doubt this problem can be fixed until Perl internals move to Unicode even for the low level file access layer, and I don't see any activity in this area by the core Perl5 Porters.

Fortunately you have discovered a workaround: You can always append an additional backslash to the filename if you are using the -d test. You could use a forward slash as well because Perl will translate it internally anyways

Comments from Jan Dubois 2004-05-18 07:39

BTW, this problem affects all filetest operators, not just -d. So while you have a workaround for -d, I see that it will be impossible to apply other file operators like the file size -s to a filename ending with a 0x5c byte. :(

It seemed a reason why "an additional backslash" is needed that a
trailing backslash is removed. It seemed to that "dir\subdir" is
converted to "dir\subdir" in library and it cause a problem.
On the other hand, trancating two or more backslashes seemed to be
work well -- "dir\subdir\" and "dir\subdir\" is treated as
"dir\subdir".

I guess "dir\subdir" should be remained as "dir\subdir" instead of
changing to "dir\subdir".

---
Flags:
category=core
severity=high
---
Site configuration information for perl v5.6.1:

Configured by ActiveState at Tue Apr 13 19:24:10 2004.

Summary of my perl5 (revision 5 version 6 subversion 1) configuration:
Platform:
osname=MSWin32, osvers=4.0, archname=MSWin32-x86-multi-thread
uname=''
config_args='undef'
hint=recommended, useposix=true, d_sigaction=undef
usethreads=undef use5005threads=undef useithreads=define usemultiplicity=define
useperlio=undef d_sfio=undef uselargefiles=undef usesocks=undef
use64bitint=undef use64bitall=undef uselongdouble=undef
Compiler:
cc='cl', ccflags ='-nologo -O1 -MD -Zi -DNDEBUG -DWIN32 -D_CONSOLE -DNO_STRICT -DHAVE_DES_FCRYPT -DPERL_IMPLICIT_CONTEXT -DPERL_IMPLICIT_SYS -DPERL_MSVCRT_READFIX',
optimize='-O1 -MD -Zi -DNDEBUG',
cppflags='-DWIN32'
ccversion='', gccversion='', gccosandvers=''
intsize=4, longsize=4, ptrsize=4, doublesize=8, byteorder=1234
d_longlong=undef, longlongsize=8, d_longdbl=define, longdblsize=10
ivtype='long', ivsize=4, nvtype='double', nvsize=8, Off_t='off_t', lseeksize=4
alignbytes=8, usemymalloc=n, prototype=define
Linker and Libraries:
ld='link', ldflags ='-nologo -nodefaultlib -debug -opt:ref,icf -libpath:"D:\Perl\lib\CORE" -machine:x86'
libpth="C:\Program Files\Microsoft Visual Studio\VC98\mfc\lib" "C:\Program Files\Microsoft Visual Studio\VC98\lib" "D:\Perl\lib\CORE"
libs= oldnames.lib kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib netapi32.lib uuid.lib wsock32.lib mpr.lib winmm.lib version.lib odbc32.lib odbccp32.lib msvcrt.lib
perllibs= oldnames.lib kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib netapi32.lib uuid.lib wsock32.lib mpr.lib winmm.lib version.lib odbc32.lib odbccp32.lib msvcrt.lib
libc=msvcrt.lib, so=dll, useshrplib=yes, libperl=perl56.lib
Dynamic Linking:
dlsrc=dl_win32.xs, dlext=dll, d_dlsymun=undef, ccdlflags=' '
cccdlflags=' ', lddlflags='-dll -nologo -nodefaultlib -debug -opt:ref,icf -libpath:"D:\Perl\lib\CORE" -machine:x86'

Locally applied patches:
ACTIVEPERL_LOCAL_PATCHES_ENTRY

---
@INC for perl v5.6.1:
D:/Perl/lib
D:/Perl/site/lib
.

---
Environment for perl v5.6.1:
HOME (unset)
LANG=ja_JP.eucJP
LANGUAGE (unset)
LD_LIBRARY_PATH (unset)
LOGDIR (unset)
PATH=D:\kabayaki\namazu\bin;D:\kabayaki\kakasi\bin;D:\kabayaki\kabayaki\bin;D:\kabayaki\kabayaki\libexec\common;D:\Perl\bin\;C:\WINNT\system32;C:\WINNT;C:\WINNT\System32\Wbem;C:\Program Files\Microsoft Visual Studio\Common\Tools\WinNT;C:\Program Files\Microsoft Visual Studio\Common\MSDev98\Bin;C:\Program Files\Microsoft Visual Studio\Common\Tools;C:\Program Files\Microsoft Visual Studio\VC98\bin
PERL_BADLANG (unset)

SHELL (unset)

From @jkeenan

Can anyone running ActivePerl, Strawberry Perl, etc., confirm that this is still a problem?

Would it be a problem on non-Windows Perls?

Thank you very much.

--
James E Keenan (jkeenan@​cpan.org)

The RT System itself - Status changed from 'new' to 'open'

From zefram@fysh.org

James E Keenan via RT wrote​:

Would it be a problem on non-Windows Perls?

It can't happen anywhere that the directory separator manifests as a
distinctive code unit that can't otherwise appear in a pathname, as is
the case on Unix.

-zefram