temp: Port to OpenBSD

In OpenBSD temperature gets fetched using sysctl now.

README

@@ -66,4 +66,3 @@ The following functions are not portable at the moment:
 - entropy
 - swap_{free,perc,total,used}
 - battery_{power,state}
-- temp

components/temperature.c

@@ -1,9 +1,16 @@
 /* See LICENSE file for copyright and license details. */
-#if defined(__linux__)
+#include <errno.h>
 #include <stdio.h>
+#include <string.h>
+#if defined(__OpenBSD__)
+#include <sys/sysctl.h>
+#include <sys/time.h>
+#include <sys/sensors.h>
+#endif
 
 #include "../util.h"
 
+#if defined(__linux__)
 const char *
 temp(const char *file)
 {
@@ -12,4 +19,27 @@ temp(const char *file)
 	return (pscanf(file, "%d", &temp) == 1) ?
 	       bprintf("%d", temp / 1000) : NULL;
 }
+#elif defined(__OpenBSD__)
+const char *
+temp(const char *null)
+{
+	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, &sz, NULL, 0) == -1) {
+		fprintf(stderr, "sysctl 'SENSOR_TEMP': %s\n", strerror(errno));
+		return NULL;
+	}
+
+	return bprintf("%d", (temp.value - 273150000) / 1000000); /* kelvin to celsius */
+}
 #endif