Modify large text file

[leulae]

I have large text file, I need to find specific value and replace it by given value.

How do I do this by reading line by line and save to same text file
(like notepad, or any other text editor does)

Thanks in advance

Leulae

[Arjay]

What do you consider "large text file"? How many MBs, GBs?

[BioPhysEngr]

You can, of course, do this in C#, but you might consider using some GNU utilities under Linux or Cygwin (under Windows) to do it as a command-line one-liner, like:

cat mytextfile.txt | sed 's/regexToFind/replaceWith/g' > mytextfile_fixed.txt

You can also do it with PowerShell on Windows, see e.g.: http://opensysblog.directorioc.net/2...owershell.html