Try to change the window title to match the command running it in. This is done

by reading argv[0] from the process group leader of the group that owns the tty
(tcgetpgrp()). This can't be done portably so some OS-dependent code is
introduced (ugh); OpenBSD, FreeBSD and Linux are supported at the moment.

A new window flag, automatic-rename, is available: if this is set to off, the
window name is not changed. Specifying a name with the new-window, new-session
or rename-window commands will automatically set this flag to off for the
window in question. To disable it entirely set the option to off globally (setw
-g automatic-rename off).

osdep-unknown.c

@@ -0,0 +1,31 @@
+/* $Id: osdep-unknown.c,v 1.1 2009-01-20 19:35:03 nicm Exp $ */
+
+/*
+ * Copyright (c) 2009 Nicholas Marriott <nicm@users.sourceforge.net>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
+ * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
+ * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#if !defined(__OpenBSD__) && !defined(__FreeBSD__) && !defined(__linux__)
+
+#include <sys/types.h>
+
+#include "tmux.h"
+
+char *
+get_argv0(unused pid_t pgrp)
+{
+	return (NULL);
+}
+
+#endif