1.\" $NetBSD: humanize_number.3,v 1.5 2005/04/11 12:19:16 wiz Exp $ 2.\" $FreeBSD: src/lib/libutil/humanize_number.3,v 1.12 2007/09/28 15:31:44 obrien Exp $ 3.\" $DragonFly: src/lib/libutil/humanize_number.3,v 1.4 2008/09/14 20:04:59 swildner Exp $ 4.\" 5.\" Copyright (c) 1999, 2002 The NetBSD Foundation, Inc. 6.\" All rights reserved. 7.\" 8.\" This code is derived from software contributed to The NetBSD Foundation 9.\" by Luke Mewburn and by Tomas Svensson. 10.\" 11.\" Redistribution and use in source and binary forms, with or without 12.\" modification, are permitted provided that the following conditions 13.\" are met: 14.\" 1. Redistributions of source code must retain the above copyright 15.\" notice, this list of conditions and the following disclaimer. 16.\" 2. Redistributions in binary form must reproduce the above copyright 17.\" notice, this list of conditions and the following disclaimer in the 18.\" documentation and/or other materials provided with the distribution. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 21.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 22.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 23.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 24.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 25.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 26.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 27.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 28.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 29.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 30.\" POSSIBILITY OF SUCH DAMAGE. 31.\" 32.Dd September 14, 2008 33.Dt HUMANIZE_NUMBER 3 34.Os 35.Sh NAME 36.Nm dehumanize_number , 37.Nm humanize_number 38.Nd format a number into a human readable form and vice versa 39.Sh LIBRARY 40.Lb libutil 41.Sh SYNOPSIS 42.In libutil.h 43.Ft int 44.Fn dehumanize_number "const char *str" "int64_t *result" 45.Ft int 46.Fo humanize_number 47.Fa "char *buf" "size_t len" "int64_t number" "const char *suffix" 48.Fa "int scale" "int flags" 49.Fc 50.Sh DESCRIPTION 51The 52.Fn humanize_number 53function formats the signed 64 bit quantity given in 54.Fa number 55into 56.Fa buffer . 57A space and then 58.Fa suffix 59is appended to the end. 60The buffer pointed to by 61.Fa buffer 62must be at least 63.Fa len 64bytes long. 65.Pp 66If the formatted number (including 67.Fa suffix ) 68would be too long to fit into 69.Fa buffer , 70then divide 71.Fa number 72by 1024 until it will. 73In this case, prefix 74.Fa suffix 75with the appropriate SI designator. 76The 77.Fn humanize_number 78function 79follows the traditional computer science conventions rather than the proposed 80SI power of two convention. 81.Pp 82The prefixes are: 83.Bl -column "Prefix" "Description" "1000000000000000000" -offset indent 84.It Sy "Prefix" Ta Sy "Description" Ta Sy "Multiplier" Ta Sy "Multiplier 1000x" 85.It Li k Ta No kilo Ta 1024 Ta 1000 86.It Li M Ta No mega Ta 1048576 Ta 1000000 87.It Li G Ta No giga Ta 1073741824 Ta 1000000000 88.It Li T Ta No tera Ta 1099511627776 Ta 1000000000000 89.It Li P Ta No peta Ta 1125899906842624 Ta 1000000000000000 90.It Li E Ta No exa Ta 1152921504606846976 Ta 1000000000000000000 91.El 92.Pp 93The 94.Fa len 95argument must be at least 4 plus the length of 96.Fa suffix , 97in order to ensure a useful result is generated into 98.Fa buffer . 99To use a specific prefix, specify this as 100.Fa scale 101(multiplier = 1024 ^ scale). 102This cannot be combined with any of the 103.Fa scale 104flags below. 105.Pp 106The following flags may be passed in 107.Fa scale : 108.Bl -tag -width ".Dv HN_DIVISOR_1000" -offset indent 109.It Dv HN_AUTOSCALE 110Format the buffer using the lowest multiplier possible. 111.It Dv HN_GETSCALE 112Return the prefix index number (the number of times 113.Fa number 114must be divided to fit) instead of formatting it to the buffer. 115.El 116.Pp 117The following flags may be passed in 118.Fa flags : 119.Bl -tag -width ".Dv HN_DIVISOR_1000" -offset indent 120.It Dv HN_DECIMAL 121If the final result is less than 10, display it using one digit. 122.It Dv HN_NOSPACE 123Do not put a space between 124.Fa number 125and the prefix. 126.It Dv HN_B 127Use 128.Ql B 129(bytes) as prefix if the original result does not have a prefix. 130.It Dv HN_DIVISOR_1000 131Divide 132.Fa number 133with 1000 instead of 1024. 134.El 135.Pp 136The 137.Fn dehumanize_number 138function parses the string representing an integral value given in 139.Fa str 140and stores the numerical value in the integer pointed to by 141.Fa result . 142The provided string may hold one of the suffixes, which will be interpreted 143and used to scale up its accompanying numerical value. 144.Sh RETURN VALUES 145The 146.Fn humanize_number 147function returns the number of characters stored in 148.Fa buffer 149(excluding the terminating 150.Dv NUL ) 151upon success, or \-1 upon failure. 152If 153.Dv HN_GETSCALE 154is specified, the prefix index number will be returned instead. 155.Pp 156The 157.Fn dehumanize_number 158function returns 0 if the string was parsed correctly. 159A \-1 is returned to indicate failure and an error code is stored in 160.Va errno . 161.Sh ERRORS 162The 163.Fn dehumanize_number 164function will fail and no number will be stored in 165.Fa result 166if: 167.Bl -tag -width Er 168.It Bq Er EINVAL 169The string in 170.Fa str 171was empty or carried an unknown suffix. 172.It Bq Er ERANGE 173The string in 174.Fa str 175represented a number that does not fit in 176.Fa result . 177.El 178.Sh HISTORY 179The 180.Fn humanize_number 181function first appeared in 182.Nx 2.0 183and then in 184.Fx 5.3 . 185.Pp 186The 187.Fn dehumanize_number 188function first appeared in 189.Nx 5.0 . 190