sed output blank in bash script -

i have file consists of following hundred lines in addition other data

(abc-wxyz1/2222 1234)

1234 random number different 100 lines. want substitute lines with

(abc-wxyz1/2222 *)

i using following code it

 cat input.txt | \      sed -i -e 's/\(abc\-wxyz1\/2222\ [0-9]\+\)/\(abc\-wxyz1\/2222\ \*\)/g' > output.txt

i output.txt blank have no clue why. doing correctly ?

if you're going use flag -i, --in place, don't have redirect output. substitutions performed in place, expected.

yet, can simplify expression, doing:

sed -i -e 's/abc\-wxyz1\/2222\ \([0-9]\+\)/*/g' input.txt

Naan