HUMANIZE_NUMBER(3) BSD Library Functions Manual HUMANIZE_NUMBER(3)NAME
dehumanize_number, humanize_number — format a number into a human read‐
able form and vice versa
LIBRARY
System Utilities Library (libutil, -lutil)
SYNOPSIS
#include <sys/types.h>
#include <libutil.h>
int
dehumanize_number(const char *str, int64_t *result);
int
humanize_number(char *buf, size_t len, int64_t number,
const char *suffix, int scale, int flags);
DESCRIPTION
The humanize_number() function formats the signed 64 bit quantity given
in number into buffer. A space and then suffix is appended to the end.
The buffer pointed to by buffer must be at least len bytes long.
If the formatted number (including suffix) would be too long to fit into
buffer, then divide number by 1024 until it will. In this case, prefix
suffix with the appropriate SI designator. The humanize_number() func‐
tion follows the traditional computer science conventions rather than the
proposed SI power of two convention.
The prefixes are:
Prefix Description Multiplier Multiplier 1000x
k kilo 1024 1000
M mega 1048576 1000000
G giga 1073741824 1000000000
T tera 1099511627776 1000000000000
P peta 1125899906842624 1000000000000000
E exa 1152921504606846976 1000000000000000000
The len argument must be at least 4 plus the length of suffix, in order
to ensure a useful result is generated into buffer. To use a specific
prefix, specify this as scale (multiplier = 1024 ^ scale). This cannot
be combined with any of the scale flags below.
The following flags may be passed in scale:
HN_AUTOSCALE Format the buffer using the lowest multiplier pos‐
sible.
HN_GETSCALE Return the prefix index number (the number of
times number must be divided to fit) instead of
formatting it to the buffer.
The following flags may be passed in flags:
HN_DECIMAL If the final result is less than 10, display it
using one digit.
HN_NOSPACE Do not put a space between number and the prefix.
HN_B Use ‘B’ (bytes) as prefix if the original result
does not have a prefix.
HN_DIVISOR_1000 Divide number with 1000 instead of 1024.
The dehumanize_number() function parses the string representing an inte‐
gral value given in str and stores the numerical value in the integer
pointed to by result. The provided string may hold one of the suffixes,
which will be interpreted and used to scale up its accompanying numerical
value.
RETURN VALUES
The humanize_number() function returns the number of characters stored in
buffer (excluding the terminating NUL) upon success, or -1 upon failure.
If HN_GETSCALE is specified, the prefix index number will be returned
instead.
The dehumanize_number() function returns 0 if the string was parsed cor‐
rectly. A -1 is returned to indicate failure and an error code is stored
in errno.
ERRORS
The dehumanize_number() function will fail and no number will be stored
in result if:
[EINVAL] The string in str was empty or carried an unknown suf‐
fix.
[ERANGE] The string in str represented a number that does not
fit in result.
HISTORY
The humanize_number() function first appeared in NetBSD 2.0 and then in
FreeBSD 5.3.
The dehumanize_number() function first appeared in NetBSD 5.0.
BSD September 14, 2008 BSD