1curs_trace(3X) curs_trace(3X)
2
6 curses_trace, trace, _tracef, _traceattr, _traceattr2, _tracecchar_t,
7 _tracecchar_t2, _tracechar, _tracechtype, _tracechtype2, _nc_tracebits,
8 _tracedump, _tracemouse - curses debugging routines
9
11 #include <curses.h>
12 unsigned curses_trace(const unsigned param);
14 void _tracef(const char *format, ...);
16 char *_traceattr(attr_t attr);
18 char *_traceattr2(int buffer, chtype ch);
19 char *_tracecchar_t(const cchar_t *string);
20 char *_tracecchar_t2(int buffer, const cchar_t *string);
21 char *_tracechar(int ch);
22 char *_tracechtype(chtype ch);
23 char *_tracechtype2(int buffer, chtype ch);
24 void _tracedump(const char *label, WINDOW *win);
26 char *_nc_tracebits(void);
27 char *_tracemouse(const MEVENT *event);
28 /* deprecated */
30 void trace(const unsigned int param);
31
33 The curses trace routines are used for debugging the ncurses libraries,
34 as well as applications which use the ncurses libraries. Some limita‐
35 tions apply:
36 · Aside from curses_trace, the other functions are normally available
38 only with the debugging library e.g., libncurses_g.a.
39 All of the trace functions may be compiled into any model (shared,
41 static, profile) by defining the symbol TRACE.
42 · Additionally, the functions which use cchar_t are only available
44 with the wide-character configuration of the libraries.
45 Functions
47 The principal parts of this interface are
48 · curses_trace, which selectively enables different tracing features,
50 and
51 · _tracef, which writes formatted data to the trace file.
53 The other functions either return a pointer to a string-area (allo‐
55 cated by the corresponding function), or return no value (such as
56 _tracedump, which implements the screen dump for TRACE_UPDATE).
57 The caller should not free these strings, since the allocation is
58 reused on successive calls. To work around the problem of a single
59 string-area per function, some use a buffer-number parameter,
60 telling the library to allocate additional string-areas.
61 The curses_trace function is always available, whether or not the other
63 trace functions are available:
64 · If tracing is available, calling curses_trace with a nonzero param‐
66 eter updates the trace mask, and returns the previous trace mask.
67 When the trace mask is nonzero, ncurses creates the file “trace” in
69 the current directory for output. If the file already exists, no
70 tracing is done.
71 · If tracing is not available, curses_trace returns zero (0).
73 Trace Parameter
75 The trace parameter is formed by OR'ing values from the list of
76 TRACE_xxx definitions in <curses.h>. These include:
77 TRACE_DISABLE
79 turn off tracing by passing a zero parameter.
80 The library flushes the output file, but retains an open file-de‐
82 scriptor to the trace file so that it can resume tracing later if
83 a nonzero parameter is passed to the curses_trace function.
84 TRACE_TIMES
86 trace user and system times of updates.
87 TRACE_TPUTS
89 trace tputs(3X) calls.
90 TRACE_UPDATE
92 trace update actions, old & new screens.
93 TRACE_MOVE
95 trace cursor movement and scrolling.
96 TRACE_CHARPUT
98 trace all character outputs.
99 TRACE_ORDINARY
101 trace all update actions. The old and new screen contents are
102 written to the trace file for each refresh.
103 TRACE_CALLS
105 trace all curses calls. The parameters for each call are traced,
106 as well as return values.
107 TRACE_VIRTPUT
109 trace virtual character puts, i.e., calls to addch.
110 TRACE_IEVENT
112 trace low-level input processing, including timeouts.
113 TRACE_BITS
115 trace state of TTY control bits.
116 TRACE_ICALLS
118 trace internal/nested calls.
119 TRACE_CCALLS
121 trace per-character calls.
122 TRACE_DATABASE
124 trace read/write of terminfo/termcap data.
125 TRACE_ATTRS
127 trace changes to video attributes and colors.
128 TRACE_MAXIMUM
130 maximum trace level, enables all of the separate trace features.
131 Some tracing features are enabled whenever the curses_trace parameter
133 is nonzero. Some features overlap. The specific names are used as a
134 guideline.
135 Initialization
137 These functions check the NCURSES_TRACE environment variable, to set
138 the tracing feature as if curses_trace was called:
139 filter, initscr, new_prescr, newterm, nofilter, restartterm,
141 ripoffline, setupterm, slk_init, tgetent, use_env,
142 use_extended_names, use_tioctl
143 Command-line Utilities
145 The command-line utilities such as tic(1) provide a verbose option
146 which extends the set of messages written using the curses_trace func‐
147 tion. Both of these (-v and curses_trace) use the same variable
148 (_nc_tracing), which determines the messages which are written.
149 Because the command-line utilities may call initialization functions
151 such as setupterm, tgetent or use_extended_names, some of their debug‐
152 ging output may be directed to the trace file if the NCURSES_TRACE en‐
153 vironment variable is set:
154 · messages produced in the utility are written to the standard error.
156 · messages produced by the underlying library are written to trace.
158 If ncurses is built without tracing, none of the latter are produced,
160 and fewer diagnostics are provided by the command-line utilities.
161
163 Routines which return a value are designed to be used as parameters to
164 the _tracef routine.
165
167 These functions are not part of the XSI interface. Some other curses
168 implementations are known to have similar features, but they are not
169 compatible with ncurses:
170 · SVr4 provided traceon and traceoff, to control whether debugging
172 information was written to the “trace” file. While the functions
173 were always available, this feature was only enabled if DEBUG was
174 defined when building the library.
175 The SVr4 tracing feature is undocumented.
177 · PDCurses provides traceon and traceoff, which (like SVr4) are al‐
179 ways available, and enable tracing to the “trace” file only when a
180 debug-library is built.
181 PDCurses has a short description of these functions, with a note
183 that they are not present in X/Open Curses, ncurses or NetBSD. It
184 does not mention SVr4, but the functions' inclusion in a header
185 file section labeled “Quasi-standard” hints at the origin.
186 · NetBSD does not provide functions for enabling/disabling traces.
188 It uses environment variables CURSES_TRACE_MASK and CURS‐
189 ES_TRACE_FILE to determine what is traced, and where the results
190 are written. This is available only when a debug-library is built.
191 The NetBSD tracing feature is undocumented.
193 A few ncurses functions are not provided when symbol versioning is
195 used:
196 _nc_tracebits, _tracedump, _tracemouse
198 The original trace routine was deprecated because it often conflicted
200 with application names.
201
203 curses(3X).
204 curs_trace(3X)