all repos — slstatus @ 46c4540dd2f6181e77b0800a4e007d78d0162487

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

components/temperature.c

/* See LICENSE file for copyright and license details. */
#include <stddef.h>

#include "../util.h"

#if defined(__linux__)
	const char *
	temp(const char *file)
	{
		int temp;

		return (pscanf(file, "%d", &temp) == 1) ?
		       bprintf("%d", temp / 1000) : NULL;
	}
#elif defined(__OpenBSD__)
	#include <errno.h>
	#include <stdio.h>
	#include <string.h>
	#include <sys/time.h> /* before <sys/sensors.h> for struct timeval */
	#include <sys/sensors.h>
	#include <sys/sysctl.h>

	const char *
	temp(const char *unused)
	{
		int mib[5];
		size_t size;
		struct sensor temp;

		mib[0] = CTL_HW;
		mib[1] = HW_SENSORS;
		mib[2] = 0; /* cpu0 */
		mib[3] = SENSOR_TEMP;
		mib[4] = 0; /* temp0 */

		size = sizeof(temp);

		if (sysctl(mib, 5, &temp, &size, NULL, 0) < 0) {
			warn("sysctl 'SENSOR_TEMP':");
			return NULL;
		}

		/* kelvin to celsius */
		return bprintf("%d", (temp.value - 273150000) / 1000000);
	}
#endif