Clozure CL and unicode on Windows

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Clozure CL and unicode on Windows

Post by Eachother » Mon Oct 19, 2009 8:49 pm


I'm having problems with reading unicode files (using (with-open-file) and (read)) that contain byte-order-mark. It seems CCL just stops reading the file after the BOM and returns the BOM as the data it has read.

Here is the code:

First, create a unicode file:

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(with-open-file (f "f" :direction :output :external-format :utf-16) (write "abc" :stream f))
Second, read the data back:

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(setf x (with-open-file (f "f" :direction :input :external-format :utf-16) (read f)))
After I execute the above code I tell the CCL "x" and it replies "\→" instead of "abc".

If I remove the BOM from the file and reread it then x is what I wrote to the file, i.e. "abc".

The same example (writing and reading the same file) works fine under CLISP (with the exception of replacing ":utf-16" with "charsets:utf-16"): the file written is the same as from CCL (it starts with 0xFEFF), data is read back successfully, x is "abc".

Could anyone help me with with?

OS is Windows.
CCL is 1.3-r11936 (WindowsX8632)
CLISP is 2.48.


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Re: Clozure CL and unicode on Windows

Post by blandest » Tue Oct 20, 2009 11:33 am

You could try to read the first two bytes (with #'read-byte) and just ignore them if they match the BOM signature.

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Re: Clozure CL and unicode on Windows

Post by nuntius » Tue Oct 20, 2009 12:49 pm

That sounds vaguely familiar. You might check on Clozure's IRC or mailing list.

I also think they are close to releasing 1.4; so you might see if a prerelease fixes this problem.

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Re: Clozure CL and unicode on Windows

Post by rme » Fri Oct 23, 2009 12:56 pm

This is a Windows-specific Clozure CL bug. It's fixed in the trunk, and will be in the forthcoming 1.4 release.

If you want to try out a pre-release of 1.4, please see

Note that you'll need to run (rebuild-ccl :clean t) after checking out a copy of the 1.4 prerelease in order to pick up the bug fix.

If you run into more CCL issues, please register on the Clozure CL Trac site ( and create a ticket. I just happened to run across your report here by accident.

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