lets say i have a file called wallpaperama.txt and this is what the files has:
Wallpaperama is an amazing collection of high resolution quality free wallpapers.
you can download your favorite wallpaper for free.
tell your friends about walllpaperama
you can vote for your favorite wallpaper
surf with confidence, all our wallpaper dont have spyware.
we hate spam, so we wouldn't give you that either.
we hope you enjoy our beautiful wallpapers
ok, on the example text file above, lets say i want to change all the 'wallpaper' to 'screensaver' well this is how you would do it..
lets assume that wallpaperama.txt is located on my home directory at: /home/me/wallpaperama.txt
step 1. open the file with the vi editor:
step 2. Enter - SHIFT + : (the Shift key and the colon key at the same time) on your keyboard, the screen will look like this:
step 3. now enter this command and hit enter
step 4. now you will see that all the text 'wallpaper' was changed to 'screensaver'
step 5. save the change with this command:
i hope this helps you