From: Rob Biedenharn <Rob@...>
Date: 2009-08-19T00:50:10+09:00
Subject: Re: fromdos dos2unix in ruby


On Aug 18, 2009, at 11:21 AM, Robert Klemme wrote:

> 2009/8/18 krzysztof cierpisz <ciapecki@gmail.com>:
>>>
>>> Well, you would read from the input file, replace the dos/windows  
>>> line
>>> endings with unix ones and write to the output file.
>>>
>>
>> I tried with following dos2unix.rb script
>>
>> ###### dos2unix.rb ######################
>> out = File.open(ARGV[1],"w")
>>
>> File.open(ARGV[0]).each {|line|
>>  out << line.gsub!(/\r$/,'')

You open the file with the default mode of 'r' here so the File class  
is going to do the line-ending conversion for you. Then you use  
String#gsub! which returns nil when no changes are made. You are never  
going to get output this way.

>> }
>>
>> out.close
>> #########################################
>>
>> this:
>> ruby dos2unix.rb u8nl_utf8_tab.dos.txt d
>>
>> works fine on Linux (d with length 408 bytes) but not on Windows, on
>> Windows d is a file with 0 bytes
>
> You are not closing the File object properly so your output might
> never get flushed to disk...
>
> Cheers
>
> robert
>
> -- 
> remember.guy do |as, often| as.you_can - without end
> http://blog.rubybestpractices.com/


Try something like this:

buffer = ''
File.open(ARGV[1], 'wb') do |out|     # open for writing binary
   File.open(ARGV[0], 'rb') do |in|    # open for reading binary
     while in.read(1024, buffer)       # read upto 1024 bytes into  
buffer
       out.write buffer.gsub(/\r\n/, "\n")  # change ending and write  
out
     end
   end                               # end of block closes input
end                                 # end of block closes output

-Rob

P.S. This is untested straight from my head.


Rob Biedenharn		http://agileconsultingllc.com
Rob@AgileConsultingLLC.com