1.\" Copyright (c) 1980, 1990, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" @(#)nice.1 8.1 (Berkeley) 6/6/93 33.\" $FreeBSD$ 34.\" 35.Dd June 6, 1993 36.Dt NICE 1 37.Os BSD 4 38.Sh NAME 39.Nm nice 40.Nd execute a command at a low scheduling priority 41.Sh SYNOPSIS 42.Nm nice 43.Op Fl Ns Ar number 44.Ar command 45.Op Ar arguments 46.Sh DESCRIPTION 47.Nm Nice 48runs 49.Ar command 50at a low priority. 51(Think of low and slow). 52If 53.Fl Ns Ar number 54is not given 55.Nm 56assumed the value 10. 57The priority is a value in the range -20 to 20. The default priority 58is 0, priority 20 is the lowest possible. 59.Nm Nice 60will execute 61.Ar command 62at priority 63.Ar number 64relative to the priority 65of 66.Nm nice . 67Higher priorities than the 68current process priority can only requested by the 69super-user. 70Negative numbers are expressed as 71.Fl - Ns Ar number . 72.Pp 73The returned exit status is the exit value from the 74command executed by 75.Nm nice . 76.Sh EXAMPLES 77.Pp 78$ nice -5 date 79.Pp 80Execute command 81.Sq date 82at priority 5 assuming the priority of the 83shell is 0. 84.Pp 85# nice -16 nice --35 date 86.Pp 87Execute command 88.Sq date 89at priority -19 assuming the priority of the 90shell is 0 and you are the super-user. 91.Sh SEE ALSO 92.Xr csh 1 , 93.Xr getpriority 2 , 94.Xr setpriority 2 , 95.Xr renice 8 96.Sh HISTORY 97A 98.Nm nice 99command appeared in 100.At v6 . 101.Sh BUGS 102.Nm Nice 103is particular to 104.Xr sh 1 . 105If you use 106.Xr csh 1 , 107then commands executed with ``&'' are automatically immune to hangup 108signals while in the background. 109.Pp 110.Nm Nice 111is built into 112.Xr csh 1 113with a slightly different syntax than described here. The form 114.Ql nice +10 115nices to positive nice, and 116.Ql nice \-10 117can be used 118by the super-user to give a process more of the processor. 119