1curs_trace(3X) curs_trace(3X)
2
6 trace, _tracef, _traceattr, _traceattr2, _tracecchar_t, _tracecchar_t2,
7 _tracechar, _tracechtype, _tracechtype2, _nc_tracebits, _tracedump,
8 _tracemouse - curses debugging routines
9
11 #include <curses.h>
12 void trace(const unsigned int 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
30 The trace routines are used for debugging the ncurses libraries, as
31 well as applications which use the ncurses libraries. These functions
32 are normally available only with the debugging library e.g., libncurs‐
33 es_g.a, but may be compiled into any model (shared, static, profile) by
34 defining the symbol TRACE. Additionally, some functions are only
35 available with the wide-character configuration of the libraries.
36 Functions
38 The principal parts of this interface are
39 · trace, which selectively enables different tracing features, and
41 · _tracef, which writes formatted data to the trace file.
43 Calling trace with a nonzero parameter creates the file trace in the
45 current directory for output. If the file already exists, no tracing
46 is done.
47 The other functions either return a pointer to a string-area (allocated
49 by the corresponding function), or return no value (such as _tracedump,
50 which implements the screen dump for TRACE_UPDATE). The caller should
51 not free these strings, since the allocation is reused on successive
52 calls. To work around the problem of a single string-area per func‐
53 tion, some use a buffer-number parameter, telling the library to allo‐
54 cate additional string-areas.
55 Trace Parameter
57 The trace parameter is formed by OR'ing values from the list of
58 TRACE_xxx definitions in <curses.h>. These include:
59 TRACE_DISABLE
61 turn off tracing by passing a zero parameter.
62 The library flushes the output file, but retains an open file-de‐
64 scriptor to the trace file so that it can resume tracing later if
65 a nonzero parameter is passed to the trace function.
66 TRACE_TIMES
68 trace user and system times of updates.
69 TRACE_TPUTS
71 trace tputs(3X) calls.
72 TRACE_UPDATE
74 trace update actions, old & new screens.
75 TRACE_MOVE
77 trace cursor movement and scrolling.
78 TRACE_CHARPUT
80 trace all character outputs.
81 TRACE_ORDINARY
83 trace all update actions. The old and new screen contents are
84 written to the trace file for each refresh.
85 TRACE_CALLS
87 trace all curses calls. The parameters for each call are traced,
88 as well as return values.
89 TRACE_VIRTPUT
91 trace virtual character puts, i.e., calls to addch.
92 TRACE_IEVENT
94 trace low-level input processing, including timeouts.
95 TRACE_BITS
97 trace state of TTY control bits.
98 TRACE_ICALLS
100 trace internal/nested calls.
101 TRACE_CCALLS
103 trace per-character calls.
104 TRACE_DATABASE
106 trace read/write of terminfo/termcap data.
107 TRACE_ATTRS
109 trace changes to video attributes and colors.
110 TRACE_MAXIMUM
112 maximum trace level, enables all of the separate trace features.
113 Some tracing features are enabled whenever the trace parameter is
115 nonzero. Some features overlap. The specific names are used as a
116 guideline.
117 Initialization
119 These functions check the NCURSES_TRACE environment variable, to set
120 the tracing feature as if trace was called:
121 filter, initscr, new_prescr, newterm, nofilter, restartterm,
123 ripoffline, setupterm, slk_init, tgetent, use_env,
124 use_extended_names, use_tioctl
125 Command-line Utilities
127 The command-line utilities such as tic(1) provide a verbose option
128 which extends the set of messages written using the trace function.
129 Both of these (-v and trace) use the same variable (_nc_tracing), which
130 determines the messages which are written.
131 Because the command-line utilities may call initialization functions
133 such as setupterm, tgetent or use_extended_names, some of their debug‐
134 ging output may be directed to the trace file if the NCURSES_TRACE en‐
135 vironment variable is set:
136 · messages produced in the utility are written to the standard error.
138 · messages produced by the underlying library are written to trace.
140 If ncurses is built without tracing, none of the latter are produced,
142 and fewer diagnostics are provided by the command-line utilities.
143
145 Routines which return a value are designed to be used as parameters to
146 the _tracef routine.
147
149 These functions are not part of the XSI interface. Some other curses
150 implementations are known to have similar, undocumented features, but
151 they are not compatible with ncurses.
152 A few functions are not provided when symbol versioning is used:
154 _nc_tracebits, _tracedump, _tracemouse
156
158 curses(3X).
159 curs_trace(3X)