.\"***************************************************************************
-.\" Copyright (c) 2000-2015,2016 Free Software Foundation, Inc. *
+.\" Copyright (c) 2000-2016,2017 Free Software Foundation, Inc. *
.\" *
.\" Permission is hereby granted, free of charge, to any person obtaining a *
.\" copy of this software and associated documentation files (the *
.\" authorization. *
.\"***************************************************************************
.\"
-.\" $Id: curs_trace.3x,v 1.16 2016/12/03 23:53:23 tom Exp $
+.\" $Id: curs_trace.3x,v 1.19 2017/11/18 23:47:37 tom Exp $
.de bP
-.IP \(bu 4
+.ie n .IP \(bu 4
+.el .IP \(bu 2
..
.TH curs_trace 3X ""
.na
trace user and system times of updates.
.TP 5
.B TRACE_TPUTS
-trace \fBtputs\fP calls.
+trace \fBtputs\fP(3X) calls.
.TP 5
.B TRACE_UPDATE
trace update actions, old & new screens.
.hy
.ad
.RE
+.SS Command-line Utilities
+.PP
+The command-line utilities such as \fBtic\fP(1) provide a verbose option
+which extends the set of messages written using the \fBtrace\fP function.
+Both of these (\fB\-v\fP and \fBtrace\fP)
+use the same variable (\fB_nc_tracing\fP),
+which determines the messages which are written.
+.PP
+Because the command-line utilities may call initialization functions
+such as \fBsetupterm\fP, \fBtgetent\fP or \fBuse_extended_names\fP,
+some of their debugging output may be directed to the \fItrace\fP file
+if the \fBNCURSES_TRACE\fP environment variable is set:
+.bP
+messages produced in the utility are written to the standard error.
+.bP
+messages produced by the underlying library are written to \fItrace\fP.
+.PP
+If ncurses is built without tracing, none of the latter are produced,
+and fewer diagnostics are provided by the command-line utilities.
.SH RETURN VALUE
Routines which return a value are designed to be used as parameters
to the \fB_tracef\fR routine.