[SOLVED] why grep is not finding words starting with underscore

Issue

I have words like

MEdIa
media
MEDIA
mEdIa
_media_
_media
media_
ICP_MEDIA

in a file. i am trying to grep the keyword media from the below command

grep -irwE "media|*_media"

But grep can find only

MEdIa
media
MEDIA
mEdIa
_media

Not able to find _media_ , media_ ,ICP_MEDIA

Solution

I'm pretty sure someone with better regex foo can provide a nicer solution, but this works for me for a selected set of values (see below):

cat file.txt  | grep -iwE "media|.*[\b_]media[\b_]*"
_media_
media
ICP_MEDIA

Values:

_media_
media
ICP_MEDIA
XXX_media_YYY
NOTMEDIA
NOT_MEDIAXX

Answered By - Christian.K

Answer Checked By - Clifford M. (WPSolving Volunteer)