all repos — slstatus @ c12b9cc50b5f476cd7b1de1dbd49e6282b1a042f

my build of slstatus (tools.suckless.org/slstatus/)

components/disk.c

/* See LICENSE file for copyright and license details. */
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <sys/statvfs.h>

#include "../util.h"

const char *
disk_free(const char *mnt)
{
	struct statvfs fs;

	if (statvfs(mnt, &fs) < 0) {
		warn("statvfs '%s':", mnt);
		return NULL;
	}

	return fmt_human_2(fs.f_frsize * fs.f_bavail, "B");
}

const char *
disk_perc(const char *mnt)
{
	struct statvfs fs;

	if (statvfs(mnt, &fs) < 0) {
		warn("statvfs '%s':", mnt);
		return NULL;
	}

	return bprintf("%d%%", (int)(100 *
	               (1.0f - ((float)fs.f_bavail / (float)fs.f_blocks))));
}

const char *
disk_total(const char *mnt)
{
	struct statvfs fs;

	if (statvfs(mnt, &fs) < 0) {
		warn("statvfs '%s':", mnt);
		return NULL;
	}

	return fmt_human_2(fs.f_frsize * fs.f_blocks, "B");
}

const char *
disk_used(const char *mnt)
{
	struct statvfs fs;

	if (statvfs(mnt, &fs) < 0) {
		warn("statvfs '%s':", mnt);
		return NULL;
	}

	return fmt_human_2(fs.f_frsize * (fs.f_blocks - fs.f_bfree), "B");
}