Why would change with "sed" via Putty not reflect in Cpanel?

I did a word replace with "sed" via Putty and i see that the word was replaced but when I open the file in cpanel there i开发者_如何学Gos no change to the file.

Here's the command

sed 's/word1/word2/g' file.php

Why would this happen?

sed 's/word1/word2/g' file.php

prints out the changed version of the file. If you want to modify the file in-place, use the -i option:

sed 's/word1/word2/g' -i file.php