curs_util 3x

curs_util(3x)                                             curs_util(3x)


       delay_output, filter, flushinp, getwin, key_name, keyname,
       nofilter, putwin, unctrl, use_env, wunctrl - miscellaneous
       curses utility routines


       #include <curses.h>

       char *unctrl(chtype c);
       wchar_t *wunctrl(cchar_t *c);
       char *keyname(int c);
       char *key_name(wchar_t w);
       void filter(void);
       void nofilter(void);
       void use_env(bool f);
       int putwin(WINDOW *win, FILE *filep);
       WINDOW *getwin(FILE *filep);
       int delay_output(int ms);
       int flushinp(void);


       The  unctrl  routine returns a character string which is a
       printable representation of the character c, ignoring  at-
       tributes.   Control characters are displayed in the ^X no-
       tation.  Printing characters are  displayed  as  is.   The
       corresponding  wunctrl  returns a printable representation
       of a wide-character.

       The keyname routine returns a character string correspond-
       ing to the key c:

          -  Printable  characters  are  displayed as themselves,
             e.g., a one-character string containing the key.

          -  Control characters are displayed in the ^X notation.

          -  DEL (character 127) is displayed as ^?.

          -  Values above 128 are either meta characters (if  the
             screen has not been initialized, or if meta has been
             called with a TRUE parameter), shown in the M-X  no-
             tation, or are displayed as themselves.  In the lat-
             ter case, the values may not be printable; this fol-
             lows the X/Open specification.

          -  Values  above  256  may be the names of the names of
             function keys.

          -  Otherwise (if there is no  corresponding  name)  the
             function  returns  null, to denote an error.  X/Open
             also lists an "UNKNOWN KEY" return value, which some
             implementations return rather than null.

       The corresponding key_name returns a character string cor-
       responding to the wide-character value w.  The  two  func-
       tions  do  not  return the same set of strings; the latter
       returns null where the former would display a meta charac-

       The filter routine, if used, must be called before initscr
       or newterm are called.  The effect is that,  during  those
       calls,  LINES  is  set  to 1; the capabilities clear, cup,
       cud, cud1, cuu1, cuu,  vpa  are  disabled;  and  the  home
       string is set to the value of cr.

       The  nofilter  routine  cancels  the effect of a preceding
       filter call.  That  allows  the  caller  to  initialize  a
       screen  on  a different device, using a different value of
       $TERM.  The limitation arises because the  filter  routine
       modifies the in-memory copy of the terminal information.

       The  use_env routine, if used, is called before initscr or
       newterm are called.  When called with FALSE  as  an  argu-
       ment,  the  values  of  lines and columns specified in the
       terminfo database will be used, even if environment  vari-
       ables  LINES  and COLUMNS (used by default) are set, or if
       curses is running in a window (in which case  default  be-
       havior  would  be to use the window size if LINES and COL-
       UMNS are not set).  Note that  setting  LINES  or  COLUMNS
       overrides  the  corresponding  size  which may be obtained
       from the operating system.

       The putwin routine writes all data associated with  window
       win into the file to which filep points.  This information
       can be later retrieved using the getwin function.

       The getwin routine reads window related data stored in the
       file  by putwin.  The routine then creates and initializes
       a new window using that data.  It returns a pointer to the
       new window.

       The  delay_output  routine inserts an ms millisecond pause
       in output.  This routine should not  be  used  extensively
       because  padding  characters  are  used  rather than a CPU
       pause.  If no padding character is  specified,  this  uses
       napms to perform the delay.

       The  flushinp  routine  throws away any typeahead that has
       been typed by the user and has not yet been  read  by  the


       Except  for  flushinp, routines that return an integer re-
       turn ERR upon failure and OK (SVr4 specifies only "an  in-
       teger value other than ERR") upon successful completion.

       Routines that return pointers return NULL on error.

       X/Open  does not define any error conditions.  In this im-

               returns an error if the terminal was not  initial-

          meta returns  an error if the terminal was not initial-

               returns an error if the  associated  fwrite  calls
               return an error.


       The  XSI  Curses  standard,  Issue 4 describes these func-
       tions.  It states that unctrl and wunctrl  will  return  a
       null  pointer if unsuccessful, but does not define any er-
       ror conditions.  This implementation checks for three cas-

              -    the  parameter is a 7-bit US-ASCII code.  This
                   is the case that X/Open Curses documented.

              -    the parameter is in the range 128-159, i.e., a
                   C1  control  code.   If  use_legacy_coding has
                   been called with a 2 parameter, unctrl returns
                   the  parameter,  i.e.,  a one-character string
                   with the parameter  as  the  first  character.
                   Otherwise,  it  returns  ``~@'', ``~A'', etc.,
                   analogous to ``^@'', ``^A'', C0 controls.

                   X/Open Curses does not document whether unctrl
                   can  be  called  before  initializing  curses.
                   This implementation permits that, and  returns
                   the ``~@'', etc., values in that case.

              -    parameter  values  outside the 0 to 255 range.
                   unctrl returns a null pointer.

       The SVr4 documentation describes the action of filter only
       in  the  vaguest  terms.   The description here is adapted
       from the XSI Curses standard (which erroneously  fails  to
       describe the disabling of cuu).

       The  strings returned by unctrl in this implementation are
       determined at compile time, showing C1 controls  from  the
       upper-128  codes with a `~' prefix rather than `^'.  Other
       implementations have different conventions.  For  example,
       they  may  show  both sets of control characters with `^',
       and strip the parameter to 7 bits.  Or they may ignore  C1
       controls  and  treat  all of the upper-128 codes as print-
       able.  This implementation uses 8 bits but does not modify
       the string to reflect locale.  The use_legacy_coding func-
       tion allows the caller to change the output of unctrl.

       Likewise, the meta function allows the  caller  to  change
       the  output of keyname, i.e., it determines whether to use
       the `M-' prefix for ``meta'' keys (codes in the range  128
       to 255).  Both use_legacy_coding and meta succeed only af-
       ter curses is initialized.  X/Open Curses does  not  docu-
       ment  the  treatment  of  codes 128 to 159.  When treating
       them as ``meta'' keys (or if keyname is called before ini-
       tializing  curses),  this  implementation  returns strings
       ``M-^@'', ``M-^A'', etc.

       The keyname function may return the names of  user-defined
       string  capabilities which are defined in the terminfo en-
       try via the -x option of tic.  This  implementation  auto-
       matically  assigns  at  run-time  keycodes to user-defined
       strings which begin  with  "k".   The  keycodes  start  at
       KEY_MAX,  but  are not guaranteed to be the same value for
       different runs because user-defined codes are merged  from
       all  terminal  descriptions  which  have been loaded.  The
       use_extended_names function controls whether this data  is
       loaded  when  the  terminal description is read by the li-

       The nofilter routine is specific to ncurses.  It  was  not
       supported  on  Version 7, BSD or System V implementations.
       It is recommended that any code depending on  ncurses  ex-
       tensions be conditioned using NCURSES_VERSION.


       legacy_coding(3x), curses(3x), curs_initscr(3x), curs_ker-
       nel(3x), curs_scr_dump(3x), legacy_coding(3x).


Man(1) output converted with man2html