1.\" $NetBSD: shuffle.1,v 1.3 2002/03/05 15:06:16 wiz Exp $ 2.\" 3.\" Copyright (c) 1998 4.\" Perry E. Metzger. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. All advertising materials mentioning features or use of this software 15.\" must display the following acknowledgment: 16.\" This product includes software developed for the NetBSD Project 17.\" by Perry E. Metzger. 18.\" 4. The name of the author may not be used to endorse or promote products 19.\" derived from this software without specific prior written permission. 20.\" 21.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 22.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 23.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 24.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 25.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 26.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 27.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 28.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 29.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 30.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 31.\" 32.\" 33.Dd September 22, 1998 34.Dt SHUFFLE 1 35.Os 36.Sh NAME 37.Nm shuffle 38.Nd print a random permutation of the command line arguments 39.Sh SYNOPSIS 40.Nm 41.Op Fl f Ar filename ... 42.Op Fl n Ar number 43.Op Fl p Ar number 44.Op Ar arg 45.Op Ar ... 46.Sh DESCRIPTION 47The 48.Nm 49program prints a random permutation (or 50.Dq shuffle ) 51of its command line arguments. 52This can be useful in shell scripts for selecting a 53random order in which to do a set of tasks, view a set of files, etc. 54.Pp 55If the 56.Fl f 57option is given, the data is taken from that files' contents or if the 58filename is 59.Ar - 60.Dq stdin . 61.Pp 62If the 63.Fl n 64option is given, its argument is treated as a number, and the program 65prints a random permutation of the numbers greater than or equal to 0 66and less than the argument. 67.Pp 68If the 69.Fl p 70option is given, its argument is treated as a number, and the program 71prints that number of randomly selected lines or arguments in a random order. 72.Sh EXAMPLES 73.Bd -literal -offset indent 74$ shuffle a b c d 75c 76b 77d 78a 79$ shuffle -p 1 a b c d 80d 81$ shuffle -n 4 -p 2 820 833 84.Ed 85.Sh SEE ALSO 86.Xr jot 1 87.Sh HISTORY 88The 89.Nm 90program first appeared in 91.Nx 1.4 . 92.Sh AUTHORS 93Written by Perry E. Metzger (perry@piermont.com). 94.Sh BUGS 95The random number generator isn't that great, and thus the 96permutations often aren't that great. 97