trace(3ncurses)

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)

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