Search and replace editor command in vi

To search and replace between line1 and line2 use following:

(*) This is vi editor command:

following command will serach and replace whole file. (this is default with %s).

:line1,$ s/old_string/new_string/g

following command will search and replace only in specific lines:

:line1,line2 s/old_string/new_string/g

for example,

:3,5 s/CIF/UOC/g

above command will replace CIF with UOC in lines 3,4 and 5.