Add hostname(1)

hostname.c

@@ -0,0 +1,33 @@
+/* See LICENSE file for copyright and license details. */
+#include <unistd.h>
+#include <stdio.h>
+#include <string.h>
+#include "util.h"
+
+static void
+usage(void)
+{
+	eprintf("usage: %s [name]\n", argv0);
+}
+
+int
+main(int argc, char *argv[])
+{
+	char buf[BUFSIZ];
+
+	ARGBEGIN {
+	default:
+		usage();
+	} ARGEND;
+
+	if (argc < 1) {
+		if (gethostname(buf, sizeof(buf)) < 0)
+			eprintf("gethostname:");
+		puts(buf);
+	} else {
+		if (sethostname(argv[0], strlen(argv[0])) < 0)
+			eprintf("sethostname:");
+	}
+
+	return 0;
+}