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.Dd August 7, 2010 .Dt HUMANIZE_NUMBER 9 .Os .Sh NAME .Nm humanize_number , .Nm format_bytes .Nd human readable numbers .Sh SYNOPSIS .Ft int .Fn humanize_number \ "char *buf" "size_t len" "uint64_t number" "const char *suffix" "int divisor" .Ft int .Fn format_bytes "char *buf" "size_t len" "uint64_t number" .Sh DESCRIPTION The .Fn humanize_number function formats the unsigned 64-bit quantity given in .Fa number into .Fa buf . A space and then .Fa suffix is appended to the end. The supplied .Fa buf must be at least .Fa len bytes long.
p If the formatted number (including .Fa suffix ) is too long to fit into .Fa buf , .Fn humanize_number divides .Fa number by .Fa divisor until it will fit. In this case, .Fa suffix is prefixed with the appropriate SI designator. Suitable values of .Fa divisor are 1024 or 1000 to remain consistent with the common meanings of the SI designator prefixes.
p The prefixes are: l -column "Prefix" "Description" "Multiplier" -offset indent t Sy "Prefix" Ta Sy "Description" Ta Sy "Multiplier" t k kilo 1024 t M mega 1048576 t G giga 1073741824 t T tera 1099511627776 t P peta 1125899906842624 t E exa 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 in .Fa buf .
p The .Fn format_bytes function is a front-end to .Fn humanize_number . It calls the latter with a .Fa suffix of .Dq B . Also, if the suffix in the returned .Fa buf would not have a prefix, the suffix is removed. This means that a result of .Dq 100000 occurs, instead of .Dq 100000 B . .Sh RETURN VALUES Both functions return the number of characters stored in .Fa buf (excluding the terminating NUL) upon success, or -1 upon failure. .Sh SEE ALSO .Xr humanize_number 3 .Sh HISTORY These functions first appeared in .Nx 1.5 .