apagar linhas com sed

Apaga linha 3

seq 1 5 | sed 3d

Apaga range de linhas de 2 a 4

seq 1 5 | sed 2,4d

Delete only lines 1, 3 and 5

seq 1 5 | sed '1d;3d;5d'

Delete lines that starts with root word

sed /^root/d /etc/passwd

Delete blank lines from file

sed /^$/d file