The trace routines are used for debugging the ncurses libraries,
as well as applications which use the ncurses libraries.
These functions are normally available only with the debugging library
libncurses_g.a, but may be compiled into any model (shared, static,
profile) by defining the symbol TRACE.
The principal parts of this interface are the trace routine which
selectively enables different tracing features, and the _tracef
routine which writes formatted data to the trace file.
Calling trace with a nonzero parameter opens the file trace
in the current directory for output. The parameter is formed by OR'ing
values from the list of TRACE_xxx definitions in <curses.h>.
These include:
TRACE_DISABLE
turn off tracing.
TRACE_TIMES
trace user and system times of updates.
TRACE_TPUTS
trace tputs calls.
TRACE_UPDATE
trace update actions, old & new screens.
TRACE_MOVE
trace cursor movement and scrolling.
TRACE_CHARPUT
trace all character outputs.
TRACE_ORDINARY
trace all update actions.
The old and new screen contents are written to the trace file
for each refresh.
TRACE_CALLS
trace all curses calls.
The parameters for each call are traced, as well as return values.
TRACE_VIRTPUT
trace virtual character puts, i.e., calls to addch.
TRACE_IEVENT
trace low-level input processing, including timeouts.
TRACE_BITS
trace state of TTY control bits.
TRACE_ICALLS
trace internal/nested calls.
TRACE_CCALLS
trace per-character calls.
TRACE_DATABASE
trace read/write of terminfo/termcap data.
TRACE_ATTRS
trace changes to video attributes and colors.
TRACE_MAXIMUM
maximum trace level, enables all of the separate trace features.
Some tracing features are enabled whenever the trace parameter
is nonzero. Some features overlap.
The specific names are used as a guideline.
RETURN VALUE
Routines which return a value are designed to be used as parameters
to the _tracef routine.
PORTABILITY
These functions are not part of the XSI interface.
Some other curses implementations are known to
have similar, undocumented features,
but they are not compatible with ncurses.
