Macintosh Terminal Pocket Guide

Name

nice — stdin  stdout  - file  -- opt  --help  --version

Synopsis

nice [-n level] command_line

When invoking a system-intensive program, you can be nice to the other processes (and users) by lowering its priority. That’s what the nice command is for: it sets a nice level (an amount of “niceness”) for a process so it gets less attention from the OS X process scheduler.^[19] Here’s an example of setting a big job to run at nice level 7:

➜ nice −n 7 sort VeryLargeFile > outfile

If you run nice without a level, 10 is used. Normal processes (run without nice) run at level zero. The superuser can also lower the nice level, increasing a process’s priority:

➜ sudo nice -n -10 myprogram

To see the nice levels of your jobs, use ps and look at the “NI” column:

➜ ps -o pid,user,args,nice

^[19] This is called “nicing” the process. You’ll hear the term used as a verb: “That process was niced to 12.”