Hello All,

How to replace a string in nth line of a file using sed or awk.

For Ex: test.txt

Line 1 : TEST1 TEST2 TEST3
Line 2 : TEST1 TEST2 TEST3 TEST4
Line 3 : TEST1 TEST2 TEST3 TEST5
Line 4 : TEST1 TEST2 TEST3 TEST6
Line 5 : TEST1 TEST2 TEST3 TEST7

i want to go to 4th line of a file and replace the word TEST2 in that line with the word DEV2.

Note : this is not a homework. just need some ideas in SED or AWK

Thanks

Rahul