utils-std

humanize.c (969B)

// utils-std: Collection of commonly available Unix tools
// SPDX-FileCopyrightText: 2017 Haelwenn (lanodan) Monnier <contact+utils@hacktivis.me>
// SPDX-License-Identifier: MPL-2.0
#define _POSIX_C_SOURCE 200809L
#include "../lib/humanize.h"
#include <math.h>  // fabs
#include <stdio.h> // snprintf
struct si_scale
dtosi(double num, bool iec)
{
#define PFX 11
	const char *si_prefixes[PFX] = {"", "k", "M", "G", "T", "P", "E", "Z", "Y", "R", "Q"};
	const char *iec_prefixes[PFX] = {
	    "B", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB", "ZiB", "YiB", "RiB", "QiB"};
	int div = iec ? 1024 : 1000;
	const char **prefixes = iec ? iec_prefixes : si_prefixes;
	bool neg = num < 0;
	struct si_scale ret = {
	    .number = fabs(num),
	    .prefix = "",
	    .exponent = 0,
	};
	while(ret.number > div && ret.exponent < (PFX - 1))
	{
		ret.number /= div;
		ret.exponent += 1;
	}
	ret.prefix = prefixes[ret.exponent];
	if(neg) ret.number = -ret.number;
	return ret;
}