Add network speed functions

components/netspeeds.c

@@ -0,0 +1,53 @@
+/* See LICENSE file for copyright and license details. */
+#include <stdio.h>
+#include <limits.h>
+
+#include "../util.h"
+
+#if defined(__linux__)
+	const char *
+	netspeed_rx(const char *interface)
+	{
+		static int valid;
+		static unsigned long long rxbytes;
+		unsigned long oldrxbytes;
+		extern const unsigned int interval;
+		char path[PATH_MAX];
+
+		oldrxbytes = rxbytes;
+		snprintf(path, sizeof(path), "/sys/class/net/%s/statistics/rx_bytes", interface);
+		if (pscanf(path, "%llu", &rxbytes) != 1) {
+			return NULL;
+		}
+		if (!valid) {
+			valid = 1;
+			return NULL;
+		}
+
+		return fmt_scaled((rxbytes - oldrxbytes) / interval * 1000);
+	}
+
+	const char *
+	netspeed_tx(const char *interface)
+	{
+		static int valid;
+		static unsigned long long txbytes;
+		unsigned long oldtxbytes;
+		extern const unsigned int interval;
+		char path[PATH_MAX];
+
+		oldtxbytes = txbytes;
+		snprintf(path, sizeof(path), "/sys/class/net/%s/statistics/tx_bytes", interface);
+		if (pscanf(path, "%llu", &txbytes) != 1) {
+			return NULL;
+		}
+		if (!valid) {
+			valid = 1;
+			return NULL;
+		}
+
+		return fmt_scaled((txbytes - oldtxbytes) / interval * 1000);
+	}
+#elif defined(__OpenBSD__)
+	/* unimplemented */
+#endif