NAME

       _tracef, _tracedump, _traceattr, _traceattr2, _nc_tracebits, _tracecchar_t,
       _tracecchar_t2, _tracechar, _tracechtype, _tracechtype2, _tracemouse, trace - curses
       debugging routines

SYNOPSIS

       #include <curses.h>

       void _tracef(const char *format, ...);
       void _tracedump(const char *label, WINDOW *win);
       char *_traceattr(attr_t attr);
       char *_traceattr2(int buffer, chtype ch);
       char *_nc_tracebits(void);
       char * _tracecchar_t(const cchar_t *string);
       char * _tracecchar_t2(int buffer, const cchar_t *string);
       char *_tracechar(int ch);
       char *_tracechtype(chtype ch);
       char *_tracechtype2(int buffer, chtype ch);
       char *_tracemouse(const MEVENT *event);
       void trace(const unsigned int param);

DESCRIPTION

       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  e.g.,  libncurses_g.a,  but  may  be  compiled into any model (shared,
       static, profile) by defining the symbol TRACE.   Additionally,  some  functions  are  only
       available with the wide-character configuration of the libraries.

       The principal parts of this interface are

       •   trace, which selectively enables different tracing features, and

       •   _tracef, 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.

       The  other  functions  either  return  a  pointer  to  a  string-area  (allocated  by  the
       corresponding  function),  or  return  no  value (such as _tracedump, which implements the
       screen dump for TRACE_UPDATE).  The caller  should  not  free  these  strings,  since  the
       allocation  is reused on successive calls.  To work around the problem of a single string-
       area per function, some use a buffer-number parameter, telling  the  library  to  allocate
       additional string-areas.

       These  functions  check the NCURSES_TRACE environment variable, to set the tracing feature
       as if trace was called:

              filter, initscr, new_prescr, newterm, nofilter, restartterm, ripoffline, setupterm,
              slk_init, tgetent, use_env, use_extended_names, use_tioctl

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.

SEE ALSO

       ncurses(3NCURSES).

                                                                                  trace(3NCURSES)