ncurses 6.2 - patch 20200425
[ncurses.git] / doc / html / man / curs_trace.3x.html
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42 <H1 class="no-header">curs_trace 3x</H1>
43 <PRE>
44 <STRONG><A HREF="curs_trace.3x.html">curs_trace(3x)</A></STRONG>                                                  <STRONG><A HREF="curs_trace.3x.html">curs_trace(3x)</A></STRONG>
45
46
47
48
49 </PRE><H2><a name="h2-NAME">NAME</a></H2><PRE>
50        <STRONG>curses_trace</STRONG>, <STRONG>trace</STRONG>, <STRONG>_tracef</STRONG>, <STRONG>_traceattr</STRONG>, <STRONG>_traceattr2</STRONG>, <STRONG>_tracecchar_t</STRONG>,
51        <STRONG>_tracecchar_t2</STRONG>, <STRONG>_tracechar</STRONG>, <STRONG>_tracechtype</STRONG>, <STRONG>_tracechtype2</STRONG>, <STRONG>_nc_tracebits</STRONG>,
52        <STRONG>_tracedump</STRONG>, <STRONG>_tracemouse</STRONG> - <STRONG>curses</STRONG> debugging routines
53
54
55 </PRE><H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE>
56        <STRONG>#include</STRONG> <STRONG>&lt;curses.h&gt;</STRONG>
57
58        <STRONG>unsigned</STRONG> <STRONG>curses_trace(const</STRONG> <STRONG>unsigned</STRONG> <EM>param</EM><STRONG>);</STRONG>
59
60        <STRONG>void</STRONG> <STRONG>_tracef(const</STRONG> <STRONG>char</STRONG> <STRONG>*</STRONG><EM>format</EM><STRONG>,</STRONG> <STRONG>...);</STRONG>
61
62        <STRONG>char</STRONG> <STRONG>*_traceattr(attr_t</STRONG> <EM>attr</EM><STRONG>);</STRONG>
63        <STRONG>char</STRONG> <STRONG>*_traceattr2(int</STRONG> <EM>buffer</EM><STRONG>,</STRONG> <STRONG>chtype</STRONG> <EM>ch</EM><STRONG>);</STRONG>
64        <STRONG>char</STRONG> <STRONG>*_tracecchar_t(const</STRONG> <STRONG>cchar_t</STRONG> <STRONG>*</STRONG><EM>string</EM><STRONG>);</STRONG>
65        <STRONG>char</STRONG> <STRONG>*_tracecchar_t2(int</STRONG> <EM>buffer</EM><STRONG>,</STRONG> <STRONG>const</STRONG> <STRONG>cchar_t</STRONG> <STRONG>*</STRONG><EM>string</EM><STRONG>);</STRONG>
66        <STRONG>char</STRONG> <STRONG>*_tracechar(int</STRONG> <EM>ch</EM><STRONG>);</STRONG>
67        <STRONG>char</STRONG> <STRONG>*_tracechtype(chtype</STRONG> <EM>ch</EM><STRONG>);</STRONG>
68        <STRONG>char</STRONG> <STRONG>*_tracechtype2(int</STRONG> <EM>buffer</EM><STRONG>,</STRONG> <STRONG>chtype</STRONG> <EM>ch</EM><STRONG>);</STRONG>
69
70        <STRONG>void</STRONG> <STRONG>_tracedump(const</STRONG> <STRONG>char</STRONG> <STRONG>*</STRONG><EM>label</EM><STRONG>,</STRONG> <STRONG>WINDOW</STRONG> <STRONG>*</STRONG><EM>win</EM><STRONG>);</STRONG>
71        <STRONG>char</STRONG> <STRONG>*_nc_tracebits(void);</STRONG>
72        <STRONG>char</STRONG> <STRONG>*_tracemouse(const</STRONG> <STRONG>MEVENT</STRONG> <STRONG>*</STRONG><EM>event</EM><STRONG>);</STRONG>
73
74        /* deprecated */
75        <STRONG>void</STRONG> <STRONG>trace(const</STRONG> <STRONG>unsigned</STRONG> <STRONG>int</STRONG> <EM>param</EM><STRONG>);</STRONG>
76
77
78 </PRE><H2><a name="h2-DESCRIPTION">DESCRIPTION</a></H2><PRE>
79        The <EM>curses</EM> <EM>trace</EM> routines are used for debugging the ncurses libraries,
80        as well as applications which use the ncurses libraries.  Some  limita-
81        tions apply:
82
83        <STRONG>o</STRONG>   Aside from <STRONG>curses_trace</STRONG>, the other functions are normally available
84            only with the debugging library e.g., <EM>libncurses</EM><STRONG>_</STRONG><EM>g.a</EM>.
85
86            All of the trace functions may be compiled into any model  (shared,
87            static, profile) by defining the symbol <STRONG>TRACE</STRONG>.
88
89        <STRONG>o</STRONG>   Additionally,  the  functions  which use <STRONG>cchar_t</STRONG> are only available
90            with the wide-character configuration of the libraries.
91
92
93 </PRE><H3><a name="h3-Functions">Functions</a></H3><PRE>
94        The principal parts of this interface are
95
96        <STRONG>o</STRONG>   <STRONG>curses_trace</STRONG>, which selectively enables different tracing features,
97            and
98
99        <STRONG>o</STRONG>   <STRONG>_tracef</STRONG>, which writes formatted data to the <EM>trace</EM> file.
100
101            The other functions either return a pointer to a string-area (allo-
102            cated by the corresponding function), or return no value  (such  as
103            <STRONG>_tracedump</STRONG>,  which  implements  the  screen dump for <STRONG>TRACE_UPDATE</STRONG>).
104            The caller should not free these strings, since the  allocation  is
105            reused on successive calls.  To work around the problem of a single
106            string-area per  function,  some  use  a  buffer-number  parameter,
107            telling the library to allocate additional string-areas.
108
109        The <STRONG>curses_trace</STRONG> function is always available, whether or not the other
110        trace functions are available:
111
112        <STRONG>o</STRONG>   If tracing is available, calling <STRONG>curses_trace</STRONG> with a nonzero param-
113            eter updates the trace mask, and returns the previous trace mask.
114
115            When the trace mask is nonzero, ncurses creates the file "trace" in
116            the current directory for output.  If the file already  exists,  no
117            tracing is done.
118
119        <STRONG>o</STRONG>   If tracing is not available, <STRONG>curses_trace</STRONG> returns zero (0).
120
121
122 </PRE><H3><a name="h3-Trace-Parameter">Trace Parameter</a></H3><PRE>
123        The  trace  parameter  is  formed  by  OR'ing  values  from the list of
124        <STRONG>TRACE_</STRONG><EM>xxx</EM> definitions in <STRONG>&lt;curses.h&gt;</STRONG>.  These include:
125
126        <STRONG>TRACE_DISABLE</STRONG>
127             turn off tracing by passing a zero parameter.
128
129             The library flushes the output file, but retains an open  file-de-
130             scriptor  to the trace file so that it can resume tracing later if
131             a nonzero parameter is passed to the <STRONG>curses_trace</STRONG> function.
132
133        <STRONG>TRACE_TIMES</STRONG>
134             trace user and system times of updates.
135
136        <STRONG>TRACE_TPUTS</STRONG>
137             trace <STRONG><A HREF="curs_terminfo.3x.html">tputs(3x)</A></STRONG> calls.
138
139        <STRONG>TRACE_UPDATE</STRONG>
140             trace update actions, old &amp; new screens.
141
142        <STRONG>TRACE_MOVE</STRONG>
143             trace cursor movement and scrolling.
144
145        <STRONG>TRACE_CHARPUT</STRONG>
146             trace all character outputs.
147
148        <STRONG>TRACE_ORDINARY</STRONG>
149             trace all update actions.  The old and  new  screen  contents  are
150             written to the trace file for each refresh.
151
152        <STRONG>TRACE_CALLS</STRONG>
153             trace  all curses calls.  The parameters for each call are traced,
154             as well as return values.
155
156        <STRONG>TRACE_VIRTPUT</STRONG>
157             trace virtual character puts, i.e., calls to <STRONG>addch</STRONG>.
158
159        <STRONG>TRACE_IEVENT</STRONG>
160             trace low-level input processing, including timeouts.
161
162        <STRONG>TRACE_BITS</STRONG>
163             trace state of TTY control bits.
164
165        <STRONG>TRACE_ICALLS</STRONG>
166             trace internal/nested calls.
167
168        <STRONG>TRACE_CCALLS</STRONG>
169             trace per-character calls.
170
171        <STRONG>TRACE_DATABASE</STRONG>
172             trace read/write of terminfo/termcap data.
173
174        <STRONG>TRACE_ATTRS</STRONG>
175             trace changes to video attributes and colors.
176
177        <STRONG>TRACE_MAXIMUM</STRONG>
178             maximum trace level, enables all of the separate trace features.
179
180        Some tracing features are enabled whenever the  <STRONG>curses_trace</STRONG>  parameter
181        is  nonzero.   Some features overlap.  The specific names are used as a
182        guideline.
183
184
185 </PRE><H3><a name="h3-Initialization">Initialization</a></H3><PRE>
186        These functions check the <STRONG>NCURSES_TRACE</STRONG> environment  variable,  to  set
187        the tracing feature as if <STRONG>curses_trace</STRONG> was called:
188
189            filter, initscr, new_prescr, newterm, nofilter, restartterm,
190            ripoffline, setupterm, slk_init, tgetent, use_env,
191            use_extended_names, use_tioctl
192
193
194 </PRE><H3><a name="h3-Command-line-Utilities">Command-line Utilities</a></H3><PRE>
195        The  command-line  utilities  such  as  <STRONG><A HREF="tic.1m.html">tic(1)</A></STRONG> provide a verbose option
196        which extends the set of messages written using the <STRONG>curses_trace</STRONG>  func-
197        tion.   Both  of  these  (<STRONG>-v</STRONG>  and  <STRONG>curses_trace</STRONG>)  use the same variable
198        (<STRONG>_nc_tracing</STRONG>), which determines the messages which are written.
199
200        Because the command-line utilities may  call  initialization  functions
201        such  as <STRONG>setupterm</STRONG>, <STRONG>tgetent</STRONG> or <STRONG>use_extended_names</STRONG>, some of their debug-
202        ging output may be directed to the <EM>trace</EM> file if the <STRONG>NCURSES_TRACE</STRONG>  en-
203        vironment variable is set:
204
205        <STRONG>o</STRONG>   messages produced in the utility are written to the standard error.
206
207        <STRONG>o</STRONG>   messages produced by the underlying library are written to <EM>trace</EM>.
208
209        If  ncurses  is built without tracing, none of the latter are produced,
210        and fewer diagnostics are provided by the command-line utilities.
211
212
213 </PRE><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE>
214        Routines which return a value are designed to be used as parameters  to
215        the <STRONG>_tracef</STRONG> routine.
216
217
218 </PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
219        These  functions  are not part of the XSI interface.  Some other curses
220        implementations are known to have similar features, but  they  are  not
221        compatible with ncurses:
222
223        <STRONG>o</STRONG>   SVr4  provided  <STRONG>traceon</STRONG>  and <STRONG>traceoff</STRONG>, to control whether debugging
224            information was written to the "trace" file.  While  the  functions
225            were  always  available, this feature was only enabled if <STRONG>DEBUG</STRONG> was
226            defined when building the library.
227
228            The SVr4 tracing feature is undocumented.
229
230        <STRONG>o</STRONG>   PDCurses provides <STRONG>traceon</STRONG> and <STRONG>traceoff</STRONG>, which (like SVr4)  are  al-
231            ways  available, and enable tracing to the "trace" file only when a
232            debug-library is built.
233
234            PDCurses has a short description of these functions,  with  a  note
235            that  they are not present in X/Open Curses, ncurses or NetBSD.  It
236            does not mention SVr4, but the functions'  inclusion  in  a  header
237            file section labeled "Quasi-standard" hints at the origin.
238
239        <STRONG>o</STRONG>   NetBSD  does  not  provide functions for enabling/disabling traces.
240            It  uses  environment   variables   <STRONG>CURSES_TRACE_MASK</STRONG>   and   <STRONG>CURS-</STRONG>
241            <STRONG>ES_TRACE_FILE</STRONG>  to  determine  what is traced, and where the results
242            are written.  This is available only when a debug-library is built.
243
244            The NetBSD tracing feature is undocumented.
245
246        A few ncurses functions are not  provided  when  symbol  versioning  is
247        used:
248
249            _nc_tracebits, _tracedump, _tracemouse
250
251        The  original  <STRONG>trace</STRONG> routine was deprecated because it often conflicted
252        with application names.
253
254
255 </PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE>
256        <STRONG><A HREF="ncurses.3x.html">curses(3x)</A></STRONG>.
257
258
259
260                                                                 <STRONG><A HREF="curs_trace.3x.html">curs_trace(3x)</A></STRONG>
261 </PRE>
262 <div class="nav">
263 <ul>
264 <li><a href="#h2-NAME">NAME</a></li>
265 <li><a href="#h2-SYNOPSIS">SYNOPSIS</a></li>
266 <li><a href="#h2-DESCRIPTION">DESCRIPTION</a>
267 <ul>
268 <li><a href="#h3-Functions">Functions</a></li>
269 <li><a href="#h3-Trace-Parameter">Trace Parameter</a></li>
270 <li><a href="#h3-Initialization">Initialization</a></li>
271 <li><a href="#h3-Command-line-Utilities">Command-line Utilities</a></li>
272 </ul>
273 </li>
274 <li><a href="#h2-RETURN-VALUE">RETURN VALUE</a></li>
275 <li><a href="#h2-PORTABILITY">PORTABILITY</a></li>
276 <li><a href="#h2-SEE-ALSO">SEE ALSO</a></li>
277 </ul>
278 </div>
279 </BODY>
280 </HTML>