HI,
I would like to know how to compare two files and replace non-matching lines with "_" .
I can get non-mathing lines with
grep -v -f file1 file2
i just want to knw how to display 'file2' with non-matching lines from 'file1' replaced by "_"
for exmaple
file1:
a
b
c
d
file2:
m
c
n
required output is :
_
_
c
_
Thanks in advance