Manpage and --help clarifications

2 files changed, 9 insertions, 6 deletions

diff --git a/ltrace.1 b/ltrace.1
index 331c223..6a6ba55 100644
--- a/ltrace.1
+++ b/ltrace.1
@@ -1,5 +1,5 @@
 .\" -*-nroff-*-
-.\" Copyright (c) 2012, 2013 Petr Machata, Red Hat Inc.
+.\" Copyright (c) 2012, 2013, 2014 Petr Machata, Red Hat Inc.
 .\" Copyright (c) 1997-2005 Juan Cespedes <cespedes@debian.org>
 .\"
 .\" This program is free software; you can redistribute it and/or
@@ -118,9 +118,9 @@ Besides removing any initial underscore prefix used by the system,
 this makes C++ function names readable.
 .IP "\-D, \-\-debug \fRmask\fI"
 Show debugging output of \fBltrace\fR itself.  \fImask\fR is a number
-with internal meaning that's not really well defined at all.
-\fImask\fR of 77 shows all debug messages, which is what you usually
-need.
+describing which debug messages should be displayed.  Use the option
+\-Dh to see what can be used, but note that currently the only
+reliable debugmask is 77, which shows all debug messages.
 .IP "\-e \fIfilter"
 A qualifying expression which modifies which library calls to trace.
 The format of the filter expression is described in the section
@@ -156,7 +156,8 @@ dependency ordering.  If you want to make sure that symbols in given
 library are actually called, use \fB-x @\fIlibrary_pattern\fR instead.
 .IP \-L
 When no \-e option is given, don't assume the default action of
-\fB@MAIN\fR.
+\fB@MAIN\fR.  In practice this means that library calls will not be
+traced.
 .IP "\-n, \-\-indent \fInr"
 Indent trace output by \fInr\fR spaces for each level of call
 nesting. Using this option makes the program flow visualization easy
diff --git a/options.c b/options.c
index 3d5dfaa..55a2c79 100644
--- a/options.c
+++ b/options.c
@@ -1,6 +1,6 @@
 /*
  * This file is part of ltrace.
- * Copyright (C) 2012, 2013 Petr Machata, Red Hat Inc.
+ * Copyright (C) 2012, 2013, 2014 Petr Machata, Red Hat Inc.
  * Copyright (C) 2009,2010 Joe Damato
  * Copyright (C) 1998,1999,2002,2003,2004,2007,2008,2009 Juan Cespedes
  * Copyright (C) 2006 Ian Wienand
@@ -128,6 +128,8 @@ usage_debug(void) {
 			"\n"
 			"Debugging options are mixed using bitwise-or.\n"
 			"Note that the meanings and values are subject to change.\n"
+			"Also note that these values are used inconsistently in ltrace, and the\n"
+			"only debuglevel that you can rely on is -D77 that will show everything.\n"
 		   );
 }