Add uptime(1)

Makefile

@@ -36,7 +36,8 @@ SRC = \
 	swapon.c            \
 	truncate.c          \
 	umount.c            \
-	unshare.c
+	unshare.c           \
+	uptime.c
 
 OBJ = $(SRC:.c=.o) $(LIB)
 BIN = $(SRC:.c=)

TODO

@@ -6,7 +6,6 @@ Tools
  * swaplabel(8)
  * last(1)
  * losetup(8)
- * uptime(1)
 
 Other
 =====

uptime.c

@@ -0,0 +1,65 @@
+/* See LICENSE file for copyright and license details. */
+#include <sys/sysinfo.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <utmp.h>
+#include "util.h"
+
+static void
+usage(void)
+{
+	eprintf("usage: %s\n", argv0);
+}
+
+int
+main(int argc, char *argv[])
+{
+	struct utmp usr;
+	FILE *ufp;
+	struct sysinfo info;
+	time_t tmptime;
+	struct tm *now;
+	unsigned int days, hours, minutes;
+	int nusers = 0;
+
+	ARGBEGIN {
+	default:
+		usage();
+	} ARGEND;
+
+	sysinfo(&info);
+	time(&tmptime);
+	now = localtime(&tmptime);
+	printf(" %02d:%02d:%02d up ", now->tm_hour, now->tm_min, now->tm_sec);
+	info.uptime /= 60;
+	minutes = info.uptime % 60;
+	info.uptime /= 60;
+	hours = info.uptime % 24;
+	days = info.uptime / 24;
+	if (days)
+		printf("%d day%s, ", days, days > 1 ? "s" : "");
+	if (hours)
+		printf("%2d:%02d, ", hours, minutes);
+	else
+		printf("%d min, ", minutes);
+
+	if ((ufp = fopen(_PATH_UTMP, "r"))) {
+		while(fread(&usr, sizeof(usr), 1, ufp) == 1) {
+			if (!*usr.ut_name || !*usr.ut_line ||
+			    usr.ut_line[0] == '~')
+				continue;
+			nusers++;
+		}
+		fclose(ufp);
+		printf(" %d user%s, ", nusers, nusers > 1 ? "s" : "");
+	}
+
+	printf(" load average: %.02f, %.02f, %.02f\n",
+	       info.loads[0] / 65536.0f,
+	       info.loads[1] / 65536.0f,
+	       info.loads[2] / 65536.0f);
+
+	return 0;
+}