Single Line replacement in file

Ruby
1

Hi All,

My code:

code.rb

lines=File.open(“hi.txt”,“r”)
output=[]
lines.each do |single|
out1=single.split(’ ‘)
out2=out1[0].gsub(’‘, ‘’)
out3= out2.gsub(’‘, ‘’)
out4=out3.gsub(’‘,’')
output << out4 # I need to overwrite the appropriate line.
end

hi.txt:

WordPress.comjazzez/ - 11k -
swik.net/jazzez - 40k -
raveendran.wordpress.com/category/jazzez/ - 15k -
www.linkedin.com/pub/2/377/3A2 - 10k -
www.bebo.com/Profile.jsp?MemberId=4902204778 -

My need:

code.rb → out contains my proper output. But i didn’t able to
overwrite the same line in file.It means

  1. single → "WordPress.comjazzez/ - 11k - "
  2. out4 → “wordpress.com/tag/jazzez”

Here i want to replace the first line in hi.txt file 1 to 2.

Awaiting your reply

Regards,
P.Raveendran
RF, chennai

2

“Raveendran J.” [email protected] schrieb im Newsbeitrag
news:[email protected]…

My need:

code.rb → out contains my proper output. But i didn’t able to
overwrite the same line in file.It means

  1. single → "WordPress.comjazzez/ - 11k - "
  2. out4 → “WordPress.com”

Here i want to replace the first line in hi.txt file 1 to 2.

You can’t replace “lines” in a file because file on disk doesn’t know
about
lines.

You can read one file, filter its content, write into another file,
close
first file, close second file, delete first file or rename to backup,
rename
second file to first file.
This would be the easiest way.

or

You read complete file into memory, filter there, seek to file start,
write
contents from memory, resize.
More dangerous on errors.

or

You replace characters of these tags by spaces directly in the file, may
be
possible but needs more repositioning in file.

I also would recommend to analyze the XML-tree instead of simply
removing
the tags wherever found.
Use, for example, “rexml” as contained in Ruby 1.8.

3

Hi Michael Bruschkewitz ,

Thanks for your detailed explanation.

You can read one file, filter its content, write into another file,
close
first file, close second file, delete first file or rename to backup,
rename
second file to first file.
This would be the easiest way.

I think this one is very simple and safety way…

Thanks.
P.Raveendran
RF, chennai

4

On Thu, Jul 31, 2008 at 6:09 AM, jazzez ravi [email protected]
wrote:

This would be the easiest way.

I think this one is very simple and safety way…

You might want to check out the -i option of Ruby.

Robert

http://ruby-smalltalk.blogspot.com/

There’s no one thing that’s true. It’s all true.