sed  '/mypattern/d' file

Deletes all lines that contain the regular expression “mypattern”.

In-place replacement:

sed --in-place '/mypattern/d' file1

sed also supports making backups with e.g. –in-place=.backup .

Maybe you want the computer to shutdown after it has done its task. This shuts down your Linux box when the load goes down to zero. Kind of like the “Speed” movies.

while ! cat /proc/loadavg |cut -f2 -d ' '|grep '0\.00'; do sleep 10m; done && poweroff

Alternatively:

while ps 12345; do sleep 10m; done && poweroff