vi ,a wonderful editor

This time , I need to globally replace a course code SEG<4 digit code> into SEEM<4 digit code> in a file . But that I only want to replace the string preceding a number , but not other words which contains the string “SEG” . Here is the vi command :

:%s/SEG\([0-9]\)/SEEM\1/g

Now everything inside “\(” and “\)” (i.e. [0-9]) is defined as 1 and that will be kept in the replaced string .

So suppose the original File is like :

SEGA
SEG1234 SATUM
SEGMENTATION
SEG2345

The result document will become :

SEGA
SEEM1234 SATUM
SEGMENTATION
SEEM2345