$FreeBSD: src/lib/libutil/humanize_number.3,v 1.8 2005/04/10 12:15:25 delphij Exp $
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.Dd May 25, 2004 .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 n 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 buffer . A space and then .Fa suffix is appended to the end. The buffer pointed to by .Fa buffer must be at least .Fa len bytes long.
p If the formatted number (including .Fa suffix ) would be too long to fit into .Fa buffer , then divide .Fa number by 1024 until it will. In this case, prefix .Fa suffix with the appropriate SI designator.
p The prefixes are: l -column "Prefix" "Description" "Multiplier" -offset indent t Sy "Prefix" Ta Sy "Description" Ta Sy "Multiplier" t Li k Ta No kilo Ta 1024 t Li M Ta No mega Ta 1048576 t Li G Ta No giga Ta 1073741824 t Li T Ta No tera Ta 1099511627776 t Li P Ta No peta Ta 1125899906842624 t Li E Ta No exa Ta 1152921504606846976 .El
p 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 buffer . To use a specific prefix, specify this as .Fa scale (multiplier = 1024 ^ scale). This cannot be combined with any of the .Fa scale flags below.
p The following flags may be passed in .Fa scale : l -tag -width ".Dv HN_DIVISOR_1000" -offset indent t Dv HN_AUTOSCALE Format the buffer using the lowest multiplier possible. t 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
p The following flags may be passed in .Fa flags : l -tag -width ".Dv HN_DIVISOR_1000" -offset indent t Dv HN_DECIMAL If the final result is less than 10, display it using one digit. t Dv HN_NOSPACE Do not put a space between .Fa number and the prefix. t Dv HN_B Use .Ql B (bytes) as prefix if the original result does not have a prefix. t Dv HN_DIVISOR_1000 Divide .Fa number with 1000 instead of 1024. .El .Sh RETURN VALUES The .Fn humanize_number function returns the number of characters stored in .Fa buffer (excluding the terminating .Dv NUL ) upon success, or -1 upon failure. If .Dv HN_GETSCALE is specified, the prefix index number will be returned instead. .Sh HISTORY The .Fn humanize_number function first appeared in .Nx 2.0 .