ps -ef |egrep lac.*python3|sed -r "s/lac2([^0-9])+([0-9]+).*/\2/"|xargs sudo renice 10
Today I needed to lower the run priority of a load of jobs running on one of my linux boxes, and this needed the above command. I was quite please with it, four commands, each piping output to the next:
ps-ef lists the running processes on the system
egrep… filters them to python3 jobs owned by a particular user
sed… strips out the process IDs from the lines for those jobs
xargs… turns each of those process IDs into an argument for “renice” which increases each processes’ niceness (that is, lowers its priority)
Beautiful.