Legends,

Can you please help me in following.
I need to comment lines from

Code:

“/tmp/a.txt”

from the line A to line B through the command prompt only.
Please use variables not direct values like 2 or 5

It can be done with VI editor but it's not matches with my requirement

Code:

 (: 2,5 s/^/#/g)

.

Please help me with the command..

Code:

/tmp:} A=2
/tmp:} B=5
/tmp:} cat /tmp/a.txt
Line no 1
Line no 2
Line no 3
Line no 4
Line no 5
Line no 6
Line no 7
Line no 8
Line no 9
Line no 10

Output should be

Code:

/tmp:} cat /tmp/a.txt
Line no 1
#Line no 2
#Line no 3
#Line no 4
#Line no 5
Line no 6
Line no 7
Line no 8
Line no 9
Line no 10