In Linux, vi is powerful to search and replace the text. Vi provides the :s (substitute) command for search and replace.

To string a text string

:s/yourtext
To see if there are additional occurrences of the same text string, type n.

Search STRING forward : / text
Search STRING backward: ? text
Repeat search: n
Repeat search in opposite direction: N

To replace one text string with another text string in the current line

:s/old_text/new_text/

To replace each occurrence of the text string:

:%s/old_text/new_text/g

Beside the above normal tips, vi also has other powerful searching/replacing abilities: search ranges, using other delimiters, getting search list etc.