NAME

       dehumanize_number, humanize_number — format a number into a human readable form and viceversa

LIBRARY

       Utility functions from BSD systems (libbsd, -lbsd)

SYNOPSIS

       #include <stdlib.h>
       (See libbsd(7) for include usage.)

       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.  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 prefixes are:

             Prefix    Description    Multiplier
             k         kilo           1024
             M         mega           1048576
             G         giga           1073741824
             T         tera           1099511627776
             P         peta           1125899906842624
             E         exa            1152921504606846976

       len  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  can  not  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 possible.

             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 integral 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

       humanize_number()  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.

       dehumanize_number()  returns  0 if the string was parsed correctly.  A -1 is returned to indicate failure
       and an error code is stored in errno.

ERRORS

       dehumanize_number() will fail and no number will be stored in result if:

       [EINVAL]           The string in str was empty or carried an unknown suffix.

       [ERANGE]           The string in str represented a number that does not fit in result.

SEE ALSO

       humanize_number(9)

HISTORY

       humanize_number() first appeared in NetBSD 2.0 and FreeBSD 5.3.

       dehumanize_number() first appeared in NetBSD 5.0.

Debian                                          February 9, 2008                           humanize_number(3bsd)