1.\" $NetBSD: humanize_number.3,v 1.4 2003/04/16 13:34:37 wiz Exp $ 2.\" $FreeBSD$ 3.\" 4.\" Copyright (c) 1999, 2002 The NetBSD Foundation, Inc. 5.\" All rights reserved. 6.\" 7.\" This code is derived from software contributed to The NetBSD Foundation 8.\" by Luke Mewburn and by Tomas Svensson. 9.\" 10.\" Redistribution and use in source and binary forms, with or without 11.\" modification, are permitted provided that the following conditions 12.\" are met: 13.\" 1. Redistributions of source code must retain the above copyright 14.\" notice, this list of conditions and the following disclaimer. 15.\" 2. Redistributions in binary form must reproduce the above copyright 16.\" notice, this list of conditions and the following disclaimer in the 17.\" documentation and/or other materials provided with the distribution. 18.\" 3. All advertising materials mentioning features or use of this software 19.\" must display the following acknowledgement: 20.\" This product includes software developed by the NetBSD 21.\" Foundation, Inc. and its contributors. 22.\" 4. Neither the name of The NetBSD Foundation nor the names of its 23.\" contributors may be used to endorse or promote products derived 24.\" from this software without specific prior written permission. 25.\" 26.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36.\" POSSIBILITY OF SUCH DAMAGE. 37.\" 38.Dd May 25, 2004 39.Dt HUMANIZE_NUMBER 3 40.Os 41.Sh NAME 42.Nm humanize_number 43.Nd format a number into a human readable form 44.Sh LIBRARY 45.Lb libutil 46.Sh SYNOPSIS 47.In libutil.h 48.Ft int 49.Fo humanize_number 50.Fa "char *buf" "size_t len" "int64_t number" "const char *suffix" 51.Fa "int scale" "int flags" 52.Fc 53.Sh DESCRIPTION 54The 55.Fn humanize_number 56function formats the signed 64-bit quantity given in 57.Fa number 58into 59.Fa buffer . 60A space and then 61.Fa suffix 62is appended to the end. 63The buffer pointed to by 64.Fa buffer 65must be at least 66.Fa len 67bytes long. 68.Pp 69If the formatted number (including 70.Fa suffix ) 71would be too long to fit into 72.Fa buffer , 73then divide 74.Fa number 75by 1024 until it will. 76In this case, prefix 77.Fa suffix 78with the appropriate SI designator. 79The 80.Fn humanize_number 81function 82follows the traditional computer science conventions rather than the proposed 83SI power of two convention. 84.Pp 85The prefixes are: 86.Bl -column "Prefix" "Description" "1000000000000000000" -offset indent 87.It Sy "Prefix" Ta Sy "Description" Ta Sy "Multiplier" Ta Sy "Multiplier 1000x" 88.It Li k Ta No kilo Ta 1024 Ta 1000 89.It Li M Ta No mega Ta 1048576 Ta 1000000 90.It Li G Ta No giga Ta 1073741824 Ta 1000000000 91.It Li T Ta No tera Ta 1099511627776 Ta 1000000000000 92.It Li P Ta No peta Ta 1125899906842624 Ta 1000000000000000 93.It Li E Ta No exa Ta 1152921504606846976 Ta 1000000000000000000 94.El 95.Pp 96The 97.Fa len 98argument must be at least 4 plus the length of 99.Fa suffix , 100in order to ensure a useful result is generated into 101.Fa buffer . 102To use a specific prefix, specify this as 103.Fa scale 104(multiplier = 1024 ^ scale). 105This cannot be combined with any of the 106.Fa scale 107flags below. 108.Pp 109The following flags may be passed in 110.Fa scale : 111.Bl -tag -width ".Dv HN_DIVISOR_1000" -offset indent 112.It Dv HN_AUTOSCALE 113Format the buffer using the lowest multiplier possible. 114.It Dv HN_GETSCALE 115Return the prefix index number (the number of times 116.Fa number 117must be divided to fit) instead of formatting it to the buffer. 118.El 119.Pp 120The following flags may be passed in 121.Fa flags : 122.Bl -tag -width ".Dv HN_DIVISOR_1000" -offset indent 123.It Dv HN_DECIMAL 124If the final result is less than 10, display it using one digit. 125.It Dv HN_NOSPACE 126Do not put a space between 127.Fa number 128and the prefix. 129.It Dv HN_B 130Use 131.Ql B 132(bytes) as prefix if the original result does not have a prefix. 133.It Dv HN_DIVISOR_1000 134Divide 135.Fa number 136with 1000 instead of 1024. 137.El 138.Sh RETURN VALUES 139The 140.Fn humanize_number 141function returns the number of characters stored in 142.Fa buffer 143(excluding the terminating 144.Dv NUL ) 145upon success, or \-1 upon failure. 146If 147.Dv HN_GETSCALE 148is specified, the prefix index number will be returned instead. 149.Sh SEE ALSO 150.Xr expand_number 3 151.Sh HISTORY 152The 153.Fn humanize_number 154function first appeared in 155.Nx 2.0 156and then in 157.Fx 5.3 . 158