From: Michael Bruschkewitz <brusch4_removethis@...>
Date: 2008-07-30T20:14:20+09:00
Subject: Re: Single Line replacement in file


"Raveendran Jazzez" <jazzezravi@gmail.com> schrieb im Newsbeitrag 
news:a65c4c849abcc50137362cbcfd7a8936@ruby-forum.com...
> 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.com/tag/<B>jazzez</B>/ - 11k - "
> 2. out4 --> "wordpress.com/tag/jazzez"
>
> 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.