HUMANIZE_NUMBER(9)					   BSD Kernel Developer's Manual					HUMANIZE_NUMBER(9)

NAME

     humanize_number, format_bytes -- human readable numbers

SYNOPSIS

     int
     humanize_number(char *buf, size_t len, uint64_t number, const char *suffix, int divisor);

     int
     format_bytes(char *buf, size_t len, uint64_t number);

DESCRIPTION

     The humanize_number() function formats the unsigned 64-bit quantity given in number into buf.  A space and then suffix is appended to the
     end.  The supplied buf must be at least len bytes long.

     If the formatted number (including suffix) is too long to fit into buf, humanize_number() divides number by divisor until it will fit.  In
     this case, suffix is prefixed with the appropriate SI designator.	Suitable values of divisor are 1024 or 1000 to remain consistent with the
     common meanings of the SI designator prefixes.

     The prefixes are:

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

     The len argument must be at least 4 plus the length of suffix, in order to ensure a useful result in buf.

     The format_bytes() function is a front-end to humanize_number().  It calls the latter with a suffix of ``B''.  Also, if the suffix in the
     returned buf would not have a prefix, the suffix is removed.  This means that a result of ``100000'' occurs, instead of ``100000 B''.

RETURN VALUES

     Both functions return the number of characters stored in buf (excluding the terminating NUL) upon success, or -1 upon failure.

SEE ALSO

     humanize_number(3)

HISTORY

     These functions first appeared in NetBSD 1.5.

BSD
								  August 7, 2010							       BSD