[lnkForumImage]
TotalShareware - Download Free Software
Confronta i prezzi di migliaia di prodotti.
Asp Forum
 Home | Login | Register | Search 


 

Forums >

comp.lang.ruby

Newbee: recursively converting LF to CRLF and vice versa

Elliott

6/22/2005 3:53:00 PM

Hello,

I'd like to recursively go through a bunch of directories and for text
file - convert any linefeed (LF) endings to carriage return line feeds
(CRLF). Ideally, I'd like to be able to do the conversion either way
and to distinguish from binary files (so that I don't bother doing any
changes to these files). Lastly, I'd like to package this utility as
a standalone .exe for windows for systems that don't have ruby on it.

I'm slowly going through the Picaxe book but I need to get this
utility done and I'd like to do it in Ruby if possible, rather than
resort to some other thing like Java (gasp). Can anyone provide me
some hints or at least some pointers to parts of Picaxe from which I
could assemble this functionality.

Anything info would be appreciated.

Elliott
7 Answers

Mark Hubbart

6/22/2005 4:09:00 PM

0

On 6/22/05, Elliott <e.hmlhml@gmail.com> wrote:
> Hello,
>
> I'd like to recursively go through a bunch of directories and for text
> file - convert any linefeed (LF) endings to carriage return line feeds
> (CRLF). Ideally, I'd like to be able to do the conversion either way
> and to distinguish from binary files (so that I don't bother doing any
> changes to these files). Lastly, I'd like to package this utility as
> a standalone .exe for windows for systems that don't have ruby on it.
>
> I'm slowly going through the Picaxe book but I need to get this
> utility done and I'd like to do it in Ruby if possible, rather than
> resort to some other thing like Java (gasp). Can anyone provide me
> some hints or at least some pointers to parts of Picaxe from which I
> could assemble this functionality.
>
> Anything info would be appreciated.

A few things to look at:

- The Find module searches recursively in directories, calling your
block of code for each file. Find it in the reference section.
- Scan for control characters in the file contents to determine
(usually) if it is binary or not. You could use a Regexp like
/[[:cntrl:]]/, which matches a single control character.
- The standalone exe can be made using RubyScript2EXE (by Erik Veen).
Find more info at http://www.erikveen.dds.nl/ruby...

HTH,
Mark

James Gray

6/22/2005 4:24:00 PM

0

On Jun 22, 2005, at 10:52 AM, Elliott wrote:

> Can anyone provide me
> some hints or at least some pointers to parts of Picaxe from which I
> could assemble this functionality.

My "hint" would be to get it working on one file first. That's
pretty easy. You can do it with a single Regexp. Then expand it to
a recursive directory search.

How do you want to detect binary files? By extension? Regexp can
probably help there too.

My "where to look advice" is the Regular Expression section (page 68)
for the conversion, the Find library (page 679) for the directory
traversal, and the OptionParser library (page 711) for the options
you want to give yourself.

I'm not knowledgeable about packaging Ruby .exe files, but I know
there are tools for this. Check out AllInOneRuby, for example.

If you really need this fast and coding it isn't a requirement, I'm
going to be blown away if a line ending conversion tool doesn't
already exist in some form.

Hope that helps.

James Edward Gray II

Berger, Daniel

6/22/2005 4:36:00 PM

0

Elliott wrote:
> Hello,
>
> I'd like to recursively go through a bunch of directories and for text
> file - convert any linefeed (LF) endings to carriage return line feeds
> (CRLF).

For the end of line conversion, see File.nl_convert, part of the
"ptools" package.

Available on the RAA.

Regards,

Dan

Ryan Leavengood

6/22/2005 4:38:00 PM

0

Elliott said:
> Hello,
>
> I'd like to recursively go through a bunch of directories and for text
> file - convert any linefeed (LF) endings to carriage return line feeds
> (CRLF). Ideally, I'd like to be able to do the conversion either way
> and to distinguish from binary files (so that I don't bother doing any
> changes to these files). Lastly, I'd like to package this utility as
> a standalone .exe for windows for systems that don't have ruby on it.
>
[snip]
> Anything info would be appreciated.

Hi Elliott,

Firstly, welcome to Ruby! :)

For the recursive directory search you will need to use the Find module.
For the conversion you will need to learn about reading and writing files
with either the IO or File classes, as well as regular expressions. Also
take a look at the FileUtils module.

As Mark Hubbart says binary files can usually be determined by looking for
control characters. Unfortunately [[:cntrl:]] matches newlines, so that
isn't the character class to use. This should work fairly well:

class File
def binary?
(self.read(100) =~ /[\x00-\x06]/) != nil
end
end

Here is a test for the above (for Windows systems with the default install
location):

['C:\ruby\bin\ruby.exe', 'C:\ruby\readme.txt'].each do |filename|
File.open(filename) do |file|
if file.binary?
puts "#{filename} is binary"
else
puts "#{filename} is NOT binary"
end
end
end

Also as Mark said, you can package up your ruby script using rubyscript2exe.

Ryan

Mark Hubbart

6/22/2005 4:48:00 PM

0

On 6/22/05, Ryan Leavengood <mrcode@netrox.net> wrote:
> As Mark Hubbart says binary files can usually be determined by looking for
> control characters. Unfortunately [[:cntrl:]] matches newlines, so that
> isn't the character class to use. This should work fairly well:

Gah! what is wrong with me? *hides face*

cheers,
Mark

Ryan Leavengood

6/22/2005 5:44:00 PM

0

Ryan Leavengood said:
>
> class File
> def binary?
> (self.read(100) =~ /[\x00-\x06]/) != nil
> end
> end

I realized the above alters the position of the filestream, so I think
this is better:

class File
def binary?
old_pos = pos
seek(0)
match = (read(100) =~ /[\x00-\x06]/)
seek(old_pos)
match != nil
end
end

Ryan

Elliott

6/22/2005 11:39:00 PM

0

Thank you all for the great information and the ways to approach this problem.