a9b02c6e96
Fix for remainder overflow, when in rare cases adding remainder to divider exceeded 1 and turned the total to 1000 in final formatting, taking up the space for the unit character. The fix continues the division of the original number if the above case happens -- added the appropriate check to the for loop performing the division. This lowers the value shown, to make it fit into the buffer space provided (1.0M for 4+1 character buffer, as used by ls). Add test case for the reported bug and extend test program to support providing buffer length (ls -lh uses 5, tests hard-coded 4). PR: 224498 Submitted by: Pawel Biernacki <pawel.biernacki@gmail.com> Reported by: Masachika Ishizuka <ish@amail.plala.or.jp> Reviewed by: cem, kib Approved by: cem, kib MFC after: 1 week Sponsored by: Mysterious Code Ltd. Differential Revision: D13578
209 lines
5.7 KiB
Groff
209 lines
5.7 KiB
Groff
.\" $NetBSD: humanize_number.3,v 1.4 2003/04/16 13:34:37 wiz Exp $
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.\" Copyright (c) 1999, 2002 The NetBSD Foundation, Inc.
|
|
.\" All rights reserved.
|
|
.\"
|
|
.\" This code is derived from software contributed to The NetBSD Foundation
|
|
.\" by Luke Mewburn and by Tomas Svensson.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
|
|
.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
|
|
.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
|
|
.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
|
|
.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
|
.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
|
.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
|
.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
|
.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
|
.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
.\" POSSIBILITY OF SUCH DAMAGE.
|
|
.\"
|
|
.Dd October 7, 2013
|
|
.Dt HUMANIZE_NUMBER 3
|
|
.Os
|
|
.Sh NAME
|
|
.Nm humanize_number
|
|
.Nd format a number into a human readable form
|
|
.Sh LIBRARY
|
|
.Lb libutil
|
|
.Sh SYNOPSIS
|
|
.In libutil.h
|
|
.Ft int
|
|
.Fo humanize_number
|
|
.Fa "char *buf" "size_t len" "int64_t number" "const char *suffix"
|
|
.Fa "int scale" "int flags"
|
|
.Fc
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Fn humanize_number
|
|
function formats the signed 64-bit quantity given in
|
|
.Fa number
|
|
into
|
|
.Fa buf .
|
|
A space and then
|
|
.Fa suffix
|
|
is appended to the end.
|
|
The buffer pointed to by
|
|
.Fa buf
|
|
must be at least
|
|
.Fa len
|
|
bytes long.
|
|
.Pp
|
|
If the formatted number (including
|
|
.Fa suffix )
|
|
would be too long to fit into
|
|
.Fa buf ,
|
|
then divide
|
|
.Fa number
|
|
by 1024 until it will.
|
|
In this case, prefix
|
|
.Fa suffix
|
|
with the appropriate designator.
|
|
The
|
|
.Fn humanize_number
|
|
function follows the traditional computer science conventions by
|
|
default, rather than the IEE/IEC (and now also SI) power of two
|
|
convention or the power of ten notion.
|
|
This behaviour however can be altered by specifying the
|
|
.Dv HN_DIVISOR_1000
|
|
and
|
|
.Dv HN_IEC_PREFIXES
|
|
flags.
|
|
.Pp
|
|
The traditional
|
|
.Pq default
|
|
prefixes are:
|
|
.Bl -column "Prefix" "Description" "1000000000000000000" -offset indent
|
|
.It Sy "Prefix" Ta Sy "Description" Ta Sy "Multiplier" Ta Sy "Multiplier 1000x"
|
|
.It Li (note) Ta No kilo Ta 1024 Ta 1000
|
|
.It Li M Ta No mega Ta 1048576 Ta 1000000
|
|
.It Li G Ta No giga Ta 1073741824 Ta 1000000000
|
|
.It Li T Ta No tera Ta 1099511627776 Ta 1000000000000
|
|
.It Li P Ta No peta Ta 1125899906842624 Ta 1000000000000000
|
|
.It Li E Ta No exa Ta 1152921504606846976 Ta 1000000000000000000
|
|
.El
|
|
.Pp
|
|
Note:
|
|
An uppercase K indicates a power of two, a lowercase k a power of ten.
|
|
.Pp
|
|
The IEE/IEC (and now also SI) power of two prefixes are:
|
|
.Bl -column "Prefix" "Description" "1000000000000000000" -offset indent
|
|
.It Sy "Prefix" Ta Sy "Description" Ta Sy "Multiplier"
|
|
.It Li Ki Ta No kibi Ta 1024
|
|
.It Li Mi Ta No mebi Ta 1048576
|
|
.It Li Gi Ta No gibi Ta 1073741824
|
|
.It Li Ti Ta No tebi Ta 1099511627776
|
|
.It Li Pi Ta No pebi Ta 1125899906842624
|
|
.It Li Ei Ta No exbi Ta 1152921504606846976
|
|
.El
|
|
.Pp
|
|
The
|
|
.Fa len
|
|
argument must be at least 4 plus the length of
|
|
.Fa suffix ,
|
|
in order to ensure a useful result is generated into
|
|
.Fa buf .
|
|
To use a specific prefix, specify this as
|
|
.Fa scale
|
|
.Po multiplier = 1024 ^ scale;
|
|
when
|
|
.Dv HN_DIVISOR_1000
|
|
is specified,
|
|
multiplier = 1000 ^ scale
|
|
.Pc .
|
|
This cannot be combined with any of the
|
|
.Fa scale
|
|
flags below.
|
|
.Pp
|
|
The following flags may be passed in
|
|
.Fa scale :
|
|
.Bl -tag -width ".Dv HN_DIVISOR_1000" -offset indent
|
|
.It Dv HN_AUTOSCALE
|
|
Format the buffer using the lowest multiplier possible.
|
|
.It Dv HN_GETSCALE
|
|
Return the prefix index number (the number of times
|
|
.Fa number
|
|
must be divided to fit) instead of formatting it to the buffer.
|
|
.El
|
|
.Pp
|
|
The following flags may be passed in
|
|
.Fa flags :
|
|
.Bl -tag -width ".Dv HN_DIVISOR_1000" -offset indent
|
|
.It Dv HN_DECIMAL
|
|
If the final result is less than 10, display it using one decimal place.
|
|
.It Dv HN_NOSPACE
|
|
Do not put a space between
|
|
.Fa number
|
|
and the prefix.
|
|
.It Dv HN_B
|
|
Use
|
|
.Ql B
|
|
(bytes) as prefix if the original result does not have a prefix.
|
|
.It Dv HN_DIVISOR_1000
|
|
Divide
|
|
.Fa number
|
|
with 1000 instead of 1024.
|
|
.It Dv HN_IEC_PREFIXES
|
|
Use the IEE/IEC notion of prefixes (Ki, Mi, Gi...).
|
|
This flag has no effect when
|
|
.Dv HN_DIVISOR_1000
|
|
is also specified.
|
|
.El
|
|
.Sh RETURN VALUES
|
|
Upon success, the
|
|
.Nm
|
|
function returns the number of characters that would have been stored in
|
|
.Fa buf
|
|
(excluding the terminating
|
|
.Dv NUL )
|
|
if
|
|
.Fa buf
|
|
was large enough, or \-1 upon failure.
|
|
Even upon failure, the contents of
|
|
.Fa buf
|
|
may be modified.
|
|
If
|
|
.Dv HN_GETSCALE
|
|
is specified, the prefix index number will be returned instead.
|
|
.Sh SEE ALSO
|
|
.Xr expand_number 3
|
|
.Sh STANDARDS
|
|
The
|
|
.Dv HN_DIVISOR_1000
|
|
and
|
|
.Dv HN_IEC_PREFIXES
|
|
flags
|
|
conform to
|
|
.Tn ISO/IEC
|
|
Std\~80000-13:2008
|
|
and
|
|
.Tn IEEE
|
|
Std\~1541-2002.
|
|
.Sh HISTORY
|
|
The
|
|
.Fn humanize_number
|
|
function first appeared in
|
|
.Nx 2.0
|
|
and then in
|
|
.Fx 5.3 .
|
|
The
|
|
.Dv HN_IEC_PREFIXES
|
|
flag was introduced in
|
|
.Fx 9.0 .
|
|
.Sh CAVEATS
|
|
For numbers greater than 999 using buffer length of 4 and less can cause
|
|
rounding errors.
|
|
When using
|
|
.Dv HN_IEC_PREFIXES
|
|
the same error occurs for buffer length of 5 or less.
|