Makefile, hru(1): add hru(1)

@@ -0,0 +86,4 @@
+		Ok(f) => f,
+		Err(err) => {
+			eprintln!("{}: {}", argv[0], err);
+			exit(1);

@@ -0,0 +17,4 @@
+
+Hru takes any whole number in the standard input and, to the standard output,
+prints the equivalent number in the most human-readable unit defined by the 
+International System of Units.

@@ -0,0 +27,4 @@
+
+use sysexits::{ EX_DATAERR, EX_SOFTWARE };
+
+const LIST: [(u32, &str); 10] = [