Re: How to read carriage return codes?

Hi Carlo, Jan,

Reading the stream as binary is indeed a good option, since it gives the
exact same results as the Hex editor (not surprisingly). This is fine for
my current use, so thanks a lot!

Jan is right, loosing locale handling is sometimes a big drawback. Are
newline handling and locate handling intertwined? I mean, would it be hard
to have an option `newline(as_is)` and locate handling at the same time?

---
Cheers!,
Wouter.

E-mail: [email protected]
WWW: www.wouterbeek.com
Tel.: 0647674624


On Tue, Jul 30, 2013 at 1:54 PM, Jan Wielemaker <[email protected]> wrote:

> On 07/30/2013 12:59 PM, Carlo Capelli wrote:
>
>> Hi Wouter
>>
>> I have this old code I used to transfer files with arbitrary encodings...
>>
>> copy_file(Source, Target) :- open(Source, read, S, [type(binary)]),
>> open(Target, write, T, [type(binary)]), copy_stream_data(S, T), close(S),
>> close(T).
>>
>
> Not sure this is what Wouter is after.  Yes, one way to get the cr is
> to open the file as binary.  That also stops interpreting character
> locale handling (e.g., UTF-8 --> Unicode).  To accommodate handling
> crlf files on POSIX platforms, there is a property called `newline'
> attached to a stream.  You can do
>
>         open(File, read, In),
>         set_stream(In, newline(posix)),
>
> which will stop newline translation.  Very hacky.  I can't really
> imagine a scenario where you would like to do that.  Somewhat more
> realistically might be
>
>         open(File, write, Out),
>         set_stream(Out, newline(dos)),
>
> which will write \r\n at the end of each line regardless of the
> operating system.
>
> The names posix and dos are a bit misleading.  Probably frustration
> trying to make programs behave consistently in mixed Windows/Unix
> environments :-(
>
>         Cheers --- Jan
>
>
>  bye Carlo
>>
>>
>>
>> 2013/7/30 Wouter Beek <[email protected]>
>>
>>  Hi all,
>>>
>>> I want to read a file with CRLF line endings to a list of codes.
>>> When I use open/3 and read_stream_to_codes/2 to do this the code list
>>> only
>>> has linefeeds (no carriage return).
>>>
>>> I'm probably overlooking something simple here... Is there a setting/flag
>>> to get the CR codes as well? I'm using 64bit Windows.
>>>
>>> The file as viewed in a Hex editor:
>>> ~~~{.hex}
>>> 0D 0A 0D 0A 0D 0A 0D 0A 0D 0A
>>> ~~~
>>>
>>> The Prolog code:
>>> ~~~
>>> :- module(crlf, []).
>>>
>>> :- use_module(library(apply)).
>>> :- use_module(library(readutil)).
>>>
>>> :- initialization(crlf).
>>>
>>> crlf:-
>>>    source_file(crlf, ThisFile),
>>>    file_directory_name(ThisFile, ThisDirectory),
>>>    absolute_file_name(
>>>      crlf,
>>>      File,
>>>      [access(read), extensions([txt]), relative_to(ThisDirectory)]
>>>    ),
>>>    open(File, read, Stream),
>>>    read_stream_to_codes(Stream, Codes),
>>>    maplist(writeln, Codes).
>>> ~~~
>>>
>>> The output of the Prolog code:
>>> ~~~
>>> 10
>>> 10
>>> 10
>>> 10
>>> 10
>>> ~~~
>>>
>>> ---
>>> Cheers!,
>>> Wouter.
>>>
>>> E-mail: [email protected]
>>> WWW: www.wouterbeek.com
>>> Tel.: 0647674624
>>> -------------- next part --------------
>>> HTML attachment scrubbed and removed
>>> -------------- next part --------------
>>>
>>>
>>>
>>>
>>>
>>> -------------- next part --------------
>>> A non-text attachment was scrubbed...
>>> Name: crlf.pl
>>> Type: application/octet-stream
>>> Size: 406 bytes
>>> Desc: not available
>>> URL: <
>>> https://lists.iai.uni-bonn.de/**pipermail/swi-prolog/**
>>> attachments/20130730/5508b300/**attachment.obj<https://lists.iai.uni-bonn.de/pipermail/swi-prolog/attachments/20130730/5508b300/attachment.obj>
>>>
>>>>
>>>>  ______________________________**_________________
>>> SWI-Prolog mailing list
>>> [email protected].**de <[email protected]>
>>> https://lists.iai.uni-bonn.de/**mailman/listinfo.cgi/swi-**prolog<https://lists.iai.uni-bonn.de/mailman/listinfo.cgi/swi-prolog>
>>>
>>>  -------------- next part --------------
>> HTML attachment scrubbed and removed
>> ______________________________**_________________
>> SWI-Prolog mailing list
>> [email protected].**de <[email protected]>
>> https://lists.iai.uni-bonn.de/**mailman/listinfo.cgi/swi-**prolog<https://lists.iai.uni-bonn.de/mailman/listinfo.cgi/swi-prolog>
>>
>>
>
>
-------------- next part --------------
HTML attachment scrubbed and removed