Regarding command Uses

Gourav Khira <[email protected]> Thu, 17 Jan 2013 11:37:24 +0530

Newsgroups	gmane.comp.gnu.utils.bugs
Message-ID	<CAJpx4+X6h8NoL9pmx83rYjMuGBz4cXGWppoPb4WzciyBUyw0Tg@mail.gmail.com>

Hi Team,

Actually, i want to replace any word with another.i used "sed" command but
it's not getting properly result.

*For Examples*:

THIS IS 1ST UPPER CASE LINE IN THE FILE.
 this is 1st lower case line in the file.

 THis is THe the mixed up line.

  Ram , Shyam, john, and Mohan are good students.

  But somya is not good girl

  This .........



If,I want to replace here "this" with "that" using "sed" command.


sed this that | filename


Please suggest me which command is right to use here and revert me ASAP.


Thanks & regards,

Gourav Khira