Skip to main content

Opening files with unicode (japanese/chinese) characters in filename using Perl

(Read a complete article on the matter and much more
"Unicode issues regarding the Window OS file system and their handling from Perl)

Currently there is no way to manipulate a file named using Unicode characters,by using Perl's built in functions.
The perl 5.10 todo wish list states that functions like chdir, opendir, readdir, readlink, rename, rmdir e.g
"could potentially accept Unicode filenames either as input or output".
Windows default encoding is UTF-16LE,but the console 'dir' command will only return ANSI names.Thus unicode characters are replaced with "?"
,even if you invoke the console using the unicode switch (cmd.exe /u),change the codepage to 65001 which is utf8 on windows and use lucida console true type font which supports unicode.
A workaround is to use the COM facilities provided by windows (in this case Scripting.FileSystemObject) which provide a much higher level of abstraction or use the Win32 api calls.
I tried to read a file with japanese characters in the filename which resides in the current folder and then move the file to another folder.
The filename is "は群馬県高崎市を拠点に、様々なメディ.txt"
Since opendir ,readdir,rename etc do not support unicode you have to reside to the Scripting.FileSystemObject methods and properties which accept unicode.

This is the actual code which moves all files with .txt extension:

use Win32::OLE qw(in);
use Devel::Peek;

#CP_UTF8 is very important as it translates between Perl strings and U
+nicode strings used by the OLE interface

Win32::OLE->Option(CP => Win32::OLE::CP_UTF8);  

$obj = Win32::OLE->new('Scripting.FileSystemObject');

$folder = $obj->GetFolder(".");

$collection= $folder->{Files};

mkdir ("c:\\newfolder")||die;

foreach $value (in $collection) {
$filename= %$value->{Name};
next if ($filename !~ /.txt/);
Dump("$filename");  #check if the utf8 flag is on
print Win32::OLE->LastError() || "success\n\n";

If all goes well then a new folder -suprsingly- called 'newfolder' in C: drive would have been created and the japanese named filed should been have moved there.

This will only work if you have the asian languages (regional setings) support enabled and you should be able to see the japanase name in explorer as above


Anonymous said…
Thanks a lot,saved me loads of time.Exactly what I needed!
Daku said…
Spent ages trying to rename a file using Win32::Unicode / Win32API::File with no luck.
This worked without any hassle, thanks :)

Popular posts from this blog

Serverless JavaScript

We recently joined in an interesting two-hour long conversation about Serverless JavaScript led by Steve Faulkner of Bustle who answered questions on Bustle, the Shep framework, the mindset behind the AWS Lambda infrastructure, and related topics.

The discussion took place on the Sideway conversation-sharing platform on January 6th. Here we present the best takeaways from the session which really should be taken notice of by anyone working on AWS.

Steve Faulkner:
At Bustle we serve over 50 million unique readers per month through a "serverless" architecture based on AWS Lambda and Node.js.  Of course there are still servers but we don't manage them. This shift has allowed us to develop products faster and decreased the cost of our infrastructure. I'll answer any questions about how we made this transition and how it has worked out. I'll also discuss some of the tools and best practises including our open source framework shep

Eran Hammer:
When would you…

First Hybrid Open-Source RDBMS Powered By Hadoop and Spark

Splice Machine is a novel attempt to merge the best parts of the traditional relational database management systems and their NoSQL counterparts with distributed and in-memory computing based on Hadoop and Spark.

Traditional RDBMS find it tough when faced with massive amounts of data, which they typically handle by scaling up, albeit expensively. Another side effect of the sheer volume of data accumulating from the likes of social media and mobile devices, is that OLTP and OLAP queries carry high performance hits that subsequently have detrimental effects on real time analysis and instant decision making.

full article on i-programmer

Google's Cloud Spanner To Settle the Relational vs NoSQL Debate?

Cloud Spanner is a new proposition for database as a service that emphatically offers "Relational with NoSQL scaling". Will Google come to dominate yet another market?

Once upon a time there was only one kind of database management system, the RDBMS, "R" for relational. Despite its resilience and trustworthiness, it had its shortcomings; it did not scale well, and the relational model it served proved inadequate in the dawn of the Big Data era for handling massive amounts of schema-less, unstructured data.
For this and a few other reasons, a new breed of DBMS's emerged, one that could handle the avalanche of big data, based on the notion of the key-value pair, and doing so by scaling horizontally. But, in order to become versatile, this new breed of management systems had to forgo the safety of the ACID and the cosiness of SQL, both long term partners of the relational model. full article on i-programmer