From: Ben Giddings <bg-rubytalk@...>
Date: 2007-10-17T10:50:53+09:00
Subject: Re: How to remove "~" in those files

On Oct 16, 2007, at 08:59, Vidya Vidya wrote:
> for sample1 records:(this is one file)
>
> LIN*EDIA000005*000000570*570~
> LIN*EDIA000006*000000570*570~
> LIN*EDIA000007*000000570*570~  // here i want to remove ~ in the  
> looping
> procees
>
> sample 2:
>
>
> LIN*EDIA000008*000000570*570~
> LIN*EDIA000009*000000570*570~
> LIN*EDIA000002*000000570*570~  // here i want to remove ~ in the  
> looping
> procees

Do you want to remove all the tilde (~) characters, or just the last  
one before "procees"?

Do you want the output to be like the following?

LIN*EDIA000005*000000570*570~
LIN*EDIA000006*000000570*570~
LIN*EDIA000007*000000570*570
procees

If so, and if you have enough space for two of the files, the easiest  
way is probably to open an "output" file and read from the input  
file, but read ahead slightly, so you know when you're at the next  
record, something like:

prev_record = nil
File.open("output.txt", "w") do |out|
   File.foreach("records.txt") do |record|
     if prev_record
       if /procees/.match(line)
         out.puts prev_record.gsub(/~$/, "")
       else
         out.puts prev_record
       end
     end
     prev_record = record
   end
   out.puts prev_record # since we were one-line behind at the end
end

FileUtils.mv("output.txt", "records.txt")

Ben