Add a totally noncompliant /bin/free

userspace/core/free.c

@@ -0,0 +1,80 @@
+/* vim: tabstop=4 shiftwidth=4 noexpandtab
+ * This file is part of ToaruOS and is released under the terms
+ * of the NCSA / University of Illinois License - see LICENSE.md
+ * Copyright (C) 2015 Kevin Lange
+ *
+ * free - Show free / used / total RAM
+ */
+#include <stdio.h>
+#include <getopt.h>
+
+void show_usage(int argc, char * argv[]) {
+	printf(
+			"free - show available memory\n"
+			"\n"
+			"usage: %s [-p]\n"
+			"\n"
+			" -u     \033[3mshow used instead of free\033[0m\n"
+			" -t     \033[3minclude a total\033[0m\n"
+			" -k     \033[3muse kilobytes instead of megabytes\033[0m\n"
+			" -?     \033[3mshow this help text\033[0m\n"
+			"\n", argv[0]);
+}
+
+
+int main(int argc, char * argv[]) {
+	int show_used = 0;
+	int use_kilobytes = 0;
+	int show_total = 0;
+
+	if (argc > 1) {
+		int index, c;
+		while ((c = getopt(argc, argv, "ktu?")) != -1) {
+			switch (c) {
+				case 'u':
+					show_used = 1;
+					break;
+				case 't':
+					show_total = 1;
+					break;
+				case 'k':
+					use_kilobytes = 1;
+					break;
+				case '?':
+					show_usage(argc, argv);
+					return 0;
+			}
+		}
+	}
+
+	const char * unit = "kB";
+
+	FILE * f = fopen("/proc/meminfo", "r");
+	if (!f) return 1;
+
+	int total, free, used;
+	fscanf(f, "MemTotal: %d kB\nMemFree: %d kB\n", &total, &free);
+	used = total - free;
+
+	if (!use_kilobytes) {
+		unit = "MB";
+		free /= 1024;
+		used /= 1024;
+		total /= 1024;
+	}
+
+	if (show_used) {
+		printf("%d %s", used, unit);
+	} else {
+		printf("%d %s", free, unit);
+	}
+
+	if (show_total) {
+		printf(" / %d %s", total, unit);
+	}
+
+	printf("\n");
+
+	return 0;
+}
+