release/src/router/libncurses/doc/html/man/curs_getch.3x.html

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  42 <H1 class="no-header">curs_getch 3x</H1>
  43 <PRE>
  44 <STRONG><A HREF="curs_getch.3x.html">curs_getch(3x)</A></STRONG>                                           <STRONG><A HREF="curs_getch.3x.html">curs_getch(3x)</A></STRONG>
  45
  46
  47
  48
  49 </PRE>
  50 <H2><a name="h2-NAME">NAME</a></H2><PRE>
  51        <STRONG>getch</STRONG>, <STRONG>wgetch</STRONG>, <STRONG>mvgetch</STRONG>, <STRONG>mvwgetch</STRONG>, <STRONG>ungetch</STRONG>, <STRONG>has_key</STRONG> - get
  52        (or push back) characters from <STRONG>curses</STRONG> terminal keyboard
  53
  54
  55 </PRE>
  56 <H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE>
  57        <STRONG>#include</STRONG> <STRONG>&lt;curses.h&gt;</STRONG>
  58
  59        <STRONG>int</STRONG> <STRONG>getch(void);</STRONG>
  60        <STRONG>int</STRONG> <STRONG>wgetch(WINDOW</STRONG> <STRONG>*</STRONG><EM>win);</EM>
  61        <STRONG>int</STRONG> <STRONG>mvgetch(int</STRONG> <EM>y</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>x</EM><STRONG>);</STRONG>
  62        <STRONG>int</STRONG> <STRONG>mvwgetch(WINDOW</STRONG> <STRONG>*</STRONG><EM>win</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>y</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>x</EM><STRONG>);</STRONG>
  63        <STRONG>int</STRONG> <STRONG>ungetch(int</STRONG> <EM>ch</EM><STRONG>);</STRONG>
  64        <STRONG>int</STRONG> <STRONG>has_key(int</STRONG> <EM>ch</EM><STRONG>);</STRONG>
  65
  66
  67 </PRE>
  68 <H2><a name="h2-DESCRIPTION">DESCRIPTION</a></H2><PRE>
  69
  70 </PRE>
  71 <H3><a name="h3-Reading-characters">Reading characters</a></H3><PRE>
  72        The <STRONG>getch</STRONG>, <STRONG>wgetch</STRONG>, <STRONG>mvgetch</STRONG> and <STRONG>mvwgetch</STRONG>, routines  read  a
  73        character  from the window.  In no-delay mode, if no input
  74        is waiting, the value <STRONG>ERR</STRONG> is returned.  In delay mode, the
  75        program  waits until the system passes text through to the
  76        program.  Depending on the setting of <STRONG>cbreak</STRONG>, this is  af-
  77        ter  one  character (cbreak mode), or after the first new-
  78        line (nocbreak mode).  In  half-delay  mode,  the  program
  79        waits  until a character is typed or the specified timeout
  80        has been reached.
  81
  82        If <STRONG>echo</STRONG> is enabled, and the window is not a pad, then  the
  83        character  will  also be echoed into the designated window
  84        according to the following rules:
  85
  86        <STRONG>o</STRONG>   If the character is the current erase character,  left
  87            arrow,  or backspace, the cursor is moved one space to
  88            the left and that screen  position  is  erased  as  if
  89            <STRONG>delch</STRONG> had been called.
  90
  91        <STRONG>o</STRONG>   If  the  character value is any other <STRONG>KEY_</STRONG> define, the
  92            user is alerted with a <STRONG>beep</STRONG> call.
  93
  94        <STRONG>o</STRONG>   If the character is a carriage-return, and  if  <STRONG>nl</STRONG>  is
  95            enabled,  it  is translated to a line-feed after echo-
  96            ing.
  97
  98        <STRONG>o</STRONG>   Otherwise  the  character  is  simply  output  to  the
  99            screen.
 100
 101        If the window is not a pad, and it has been moved or modi-
 102        fied since the last call to  <STRONG>wrefresh</STRONG>,  <STRONG>wrefresh</STRONG>  will  be
 103        called before another character is read.
 104
 105
 106 </PRE>
 107 <H3><a name="h3-Keypad-mode">Keypad mode</a></H3><PRE>
 108        If  <STRONG>keypad</STRONG> is <STRONG>TRUE</STRONG>, and a function key is pressed, the to-
 109        ken for that function key is returned instead of  the  raw
 110        characters.   Possible function keys are defined in <STRONG>&lt;curs-</STRONG>
 111        <STRONG>es.h&gt;</STRONG> as macros with values outside  the  range  of  8-bit
 112        characters  whose names begin with <STRONG>KEY_</STRONG>.  Thus, a variable
 113        intended to hold the return value of a function  key  must
 114        be of short size or larger.
 115
 116        When a character that could be the beginning of a function
 117        key is received (which, on modern terminals, means an  es-
 118        cape character), <STRONG>curses</STRONG> sets a timer.  If the remainder of
 119        the sequence does not come in within the designated  time,
 120        the  character  is passed through; otherwise, the function
 121        key value is returned.  For this  reason,  many  terminals
 122        experience a delay between the time a user presses the es-
 123        cape key and the escape is returned to the program.
 124
 125
 126 </PRE>
 127 <H3><a name="h3-Ungetting-characters">Ungetting characters</a></H3><PRE>
 128        The <STRONG>ungetch</STRONG> routine places <EM>ch</EM> back onto the input queue to
 129        be returned by the next call to <STRONG>wgetch</STRONG>.  There is just one
 130        input queue for all windows.
 131
 132
 133 </PRE>
 134 <H3><a name="h3-Predefined-key-codes">Predefined key-codes</a></H3><PRE>
 135        The following special keys, defined in <STRONG>&lt;curses.h&gt;</STRONG>, may  be
 136        returned  by <STRONG>getch</STRONG> if <STRONG>keypad</STRONG> has been enabled.  Not all of
 137        these are necessarily supported on any  particular  termi-
 138        nal.
 139
 140             <EM>Name</EM>            <EM>Key</EM> <EM>name</EM>
 141             -------------------------------------------------
 142             KEY_BREAK       Break key
 143             KEY_DOWN        The four arrow keys ...
 144             KEY_UP
 145             KEY_LEFT
 146             KEY_RIGHT
 147             KEY_HOME        Home key (upward+left arrow)
 148             KEY_BACKSPACE   Backspace
 149             KEY_F0          Function keys; space for 64 keys
 150                             is reserved.
 151             KEY_F(<EM>n</EM>)        For 0 &lt;= <EM>n</EM> &lt;= 63
 152             KEY_DL          Delete line
 153             KEY_IL          Insert line
 154             KEY_DC          Delete character
 155             KEY_IC          Insert char or enter insert mode
 156             KEY_EIC         Exit insert char mode
 157             KEY_CLEAR       Clear screen
 158             KEY_EOS         Clear to end of screen
 159             KEY_EOL         Clear to end of line
 160             KEY_SF          Scroll 1 line forward
 161             KEY_SR          Scroll 1 line backward (reverse)
 162             KEY_NPAGE       Next page
 163             KEY_PPAGE       Previous page
 164             KEY_STAB        Set tab
 165             KEY_CTAB        Clear tab
 166             KEY_CATAB       Clear all tabs
 167             KEY_ENTER       Enter or send
 168             KEY_SRESET      Soft (partial) reset
 169             KEY_RESET       Reset or hard reset
 170             KEY_PRINT       Print or copy
 171             KEY_LL          Home down or bottom (lower left)
 172             KEY_A1          Upper left of keypad
 173             KEY_A3          Upper right of keypad
 174             KEY_B2          Center of keypad
 175             KEY_C1          Lower left of keypad
 176             KEY_C3          Lower right of keypad
 177             KEY_BTAB        Back tab key
 178             KEY_BEG         Beg(inning) key
 179             KEY_CANCEL      Cancel key
 180             KEY_CLOSE       Close key
 181             KEY_COMMAND     Cmd (command) key
 182             KEY_COPY        Copy key
 183             KEY_CREATE      Create key
 184             KEY_END         End key
 185             KEY_EXIT        Exit key
 186             KEY_FIND        Find key
 187             KEY_HELP        Help key
 188             KEY_MARK        Mark key
 189
 190             KEY_MESSAGE     Message key
 191             KEY_MOUSE       Mouse event read
 192             KEY_MOVE        Move key
 193             KEY_NEXT        Next object key
 194             KEY_OPEN        Open key
 195             KEY_OPTIONS     Options key
 196             KEY_PREVIOUS    Previous object key
 197             KEY_REDO        Redo key
 198             KEY_REFERENCE   Ref(erence) key
 199             KEY_REFRESH     Refresh key
 200             KEY_REPLACE     Replace key
 201             KEY_RESIZE      Screen resized
 202             KEY_RESTART     Restart key
 203             KEY_RESUME      Resume key
 204             KEY_SAVE        Save key
 205             KEY_SBEG        Shifted beginning key
 206             KEY_SCANCEL     Shifted cancel key
 207             KEY_SCOMMAND    Shifted command key
 208             KEY_SCOPY       Shifted copy key
 209             KEY_SCREATE     Shifted create key
 210             KEY_SDC         Shifted delete char key
 211             KEY_SDL         Shifted delete line key
 212             KEY_SELECT      Select key
 213             KEY_SEND        Shifted end key
 214             KEY_SEOL        Shifted clear line key
 215             KEY_SEXIT       Shifted exit key
 216             KEY_SFIND       Shifted find key
 217             KEY_SHELP       Shifted help key
 218             KEY_SHOME       Shifted home key
 219             KEY_SIC         Shifted input key
 220             KEY_SLEFT       Shifted left arrow key
 221             KEY_SMESSAGE    Shifted message key
 222             KEY_SMOVE       Shifted move key
 223             KEY_SNEXT       Shifted next key
 224             KEY_SOPTIONS    Shifted options key
 225             KEY_SPREVIOUS   Shifted prev key
 226             KEY_SPRINT      Shifted print key
 227             KEY_SREDO       Shifted redo key
 228             KEY_SREPLACE    Shifted replace key
 229             KEY_SRIGHT      Shifted right arrow
 230             KEY_SRSUME      Shifted resume key
 231             KEY_SSAVE       Shifted save key
 232             KEY_SSUSPEND    Shifted suspend key
 233             KEY_SUNDO       Shifted undo key
 234             KEY_SUSPEND     Suspend key
 235             KEY_UNDO        Undo key
 236
 237        Keypad is arranged like this:
 238
 239                          +-----+------+-------+
 240                          | <STRONG>A1</STRONG>  |  <STRONG>up</STRONG>  |  <STRONG>A3</STRONG>   |
 241                          +-----+------+-------+
 242                          |<STRONG>left</STRONG> |  <STRONG>B2</STRONG>  | <STRONG>right</STRONG> |
 243                          +-----+------+-------+
 244                          | <STRONG>C1</STRONG>  | <STRONG>down</STRONG> |  <STRONG>C3</STRONG>   |
 245                          +-----+------+-------+
 246        A few of these predefined values do <EM>not</EM>  correspond  to  a
 247        real key:
 248
 249        <STRONG>o</STRONG>   <STRONG>KEY_RESIZE</STRONG>  is  returned  when the <STRONG>SIGWINCH</STRONG> signal has
 250            been detected (see <STRONG><A HREF="curs_initscr.3x.html">curs_initscr(3x)</A></STRONG> and <STRONG><A HREF="resizeterm.3x.html">resizeterm(3x)</A></STRONG>).
 251
 252        <STRONG>o</STRONG>   <STRONG>KEY_MOUSE</STRONG>   is   returned   for   mouse-events    (see
 253            <STRONG><A HREF="curs_mouse.3x.html">curs_mouse(3x)</A></STRONG>).
 254
 255
 256 </PRE>
 257 <H3><a name="h3-Testing-key-codes">Testing key-codes</a></H3><PRE>
 258        The  <STRONG>has_key</STRONG> routine takes a key-code value from the above
 259        list, and returns <STRONG>TRUE</STRONG> or <STRONG>FALSE</STRONG> according to  whether  the
 260        current terminal type recognizes a key with that value.
 261
 262        The library also supports these extensions:
 263
 264           <STRONG>define_key</STRONG>
 265                defines  a  key-code  for  a given string (see <STRONG>de-</STRONG>
 266                <STRONG><A HREF="define_key.3x.html">fine_key(3x)</A></STRONG>).
 267
 268           <STRONG>key_defined</STRONG>
 269                checks if there is a key-code defined for a  given
 270                string (see <STRONG><A HREF="key_defined.3x.html">key_defined(3x)</A></STRONG>).
 271
 272
 273 </PRE>
 274 <H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE>
 275        All  routines  return  the integer <STRONG>ERR</STRONG> upon failure and an
 276        integer value other than <STRONG>ERR</STRONG> (<STRONG>OK</STRONG> in the case of ungetch())
 277        upon successful completion.
 278
 279           <STRONG>ungetch</STRONG>
 280                returns ERR if there is no more room in the FIFO.
 281
 282           <STRONG>wgetch</STRONG>
 283                returns  ERR  if the window pointer is null, or if
 284                its timeout expires without having any data.
 285
 286        Functions with a "mv" prefix first perform a cursor  move-
 287        ment  using  <STRONG>wmove</STRONG>, and return an error if the position is
 288        outside the window, or if the window pointer is null.
 289
 290
 291 </PRE>
 292 <H2><a name="h2-NOTES">NOTES</a></H2><PRE>
 293        Use of the escape key by a programmer for a single charac-
 294        ter  function  is discouraged, as it will cause a delay of
 295        up to one second while the keypad code looks for a follow-
 296        ing function-key sequence.
 297
 298        Some  keys  may be the same as commonly used control keys,
 299        e.g., <STRONG>KEY_ENTER</STRONG>  versus  control/M,  <STRONG>KEY_BACKSPACE</STRONG>  versus
 300        control/H.  Some curses implementations may differ accord-
 301        ing to whether they treat  these  control  keys  specially
 302        (and  ignore  the  terminfo),  or use the terminfo defini-
 303        tions.  <STRONG>Ncurses</STRONG> uses the terminfo definition.  If it  says
 304        that  <STRONG>KEY_ENTER</STRONG>  is control/M, <STRONG>getch</STRONG> will return <STRONG>KEY_ENTER</STRONG>
 305        when you press control/M.
 306
 307        Generally, <STRONG>KEY_ENTER</STRONG> denotes the character(s) sent by  the
 308        <EM>Enter</EM> key on the numeric keypad:
 309
 310        <STRONG>o</STRONG>   the terminal description lists the most useful keys,
 311
 312        <STRONG>o</STRONG>   the  <EM>Enter</EM> key on the regular keyboard is already han-
 313            dled by the standard ASCII characters for carriage-re-
 314            turn and line-feed,
 315
 316        <STRONG>o</STRONG>   depending  on  whether <STRONG>nl</STRONG> or <STRONG>nonl</STRONG> was called, pressing
 317            "Enter" on the regular keyboard may  return  either  a
 318            carriage-return or line-feed, and finally
 319
 320        <STRONG>o</STRONG>   "Enter  or  send" is the standard description for this
 321            key.
 322
 323        When using <STRONG>getch</STRONG>, <STRONG>wgetch</STRONG>, <STRONG>mvgetch</STRONG>, or  <STRONG>mvwgetch</STRONG>,  nocbreak
 324        mode (<STRONG>nocbreak</STRONG>) and echo mode (<STRONG>echo</STRONG>) should not be used at
 325        the same time.  Depending on the state of the  tty  driver
 326        when  each character is typed, the program may produce un-
 327        desirable results.
 328
 329        Note that <STRONG>getch</STRONG>, <STRONG>mvgetch</STRONG>, and <STRONG>mvwgetch</STRONG> may be macros.
 330
 331        Historically, the set of keypad macros was largely defined
 332        by  the  extremely  function-key-rich keyboard of the AT&amp;T
 333        7300, aka 3B1, aka Safari 4.   Modern  personal  computers
 334        usually  have  only a small subset of these.  IBM PC-style
 335        consoles  typically  support  little  more  than   <STRONG>KEY_UP</STRONG>,
 336        <STRONG>KEY_DOWN</STRONG>,    <STRONG>KEY_LEFT</STRONG>,   <STRONG>KEY_RIGHT</STRONG>,   <STRONG>KEY_HOME</STRONG>,   <STRONG>KEY_END</STRONG>,
 337        <STRONG>KEY_NPAGE</STRONG>, <STRONG>KEY_PPAGE</STRONG>, and function keys 1 through 12.  The
 338        Ins key is usually mapped to <STRONG>KEY_IC</STRONG>.
 339
 340
 341 </PRE>
 342 <H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
 343        The  *get* functions are described in the XSI Curses stan-
 344        dard, Issue 4.  They  read  single-byte  characters  only.
 345        The  standard  specifies  that they return <STRONG>ERR</STRONG> on failure,
 346        but specifies no error conditions.
 347
 348        The echo behavior of these functions on input of  <STRONG>KEY_</STRONG>  or
 349        backspace  characters  was not specified in the SVr4 docu-
 350        mentation.  This description is adopted from the XSI Curs-
 351        es standard.
 352
 353        The  behavior of <STRONG>getch</STRONG> and friends in the presence of han-
 354        dled signals is unspecified in the  SVr4  and  XSI  Curses
 355        documentation.   Under  historical curses implementations,
 356        it varied depending on whether the operating system's  im-
 357        plementation   of  handled  signal  receipt  interrupts  a
 358        <STRONG>read(2)</STRONG> call in progress or not, and also (in some  imple-
 359        mentations)  depending on whether an input timeout or non-
 360        blocking mode has been set.
 361
 362        Programmers concerned about portability should be prepared
 363        for  either  of two cases: (a) signal receipt does not in-
 364        terrupt <STRONG>getch</STRONG>; (b) signal  receipt  interrupts  <STRONG>getch</STRONG>  and
 365        causes  it  to  return ERR with <STRONG>errno</STRONG> set to <STRONG>EINTR</STRONG>.  Under
 366        the <STRONG>ncurses</STRONG> implementation, handled signals  never  inter-
 367        rupt <STRONG>getch</STRONG>.
 368
 369        The  <STRONG>has_key</STRONG>  function is unique to <STRONG>ncurses</STRONG>.  We recommend
 370        that any code using it be conditionalized  on  the  <STRONG>NCURS-</STRONG>
 371        <STRONG>ES_VERSION</STRONG> feature macro.
 372
 373
 374 </PRE>
 375 <H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE>
 376        <STRONG><A HREF="ncurses.3x.html">curses(3x)</A></STRONG>,       <STRONG><A HREF="curs_inopts.3x.html">curs_inopts(3x)</A></STRONG>,       <STRONG><A HREF="curs_outopts.3x.html">curs_outopts(3x)</A></STRONG>,
 377        <STRONG><A HREF="curs_mouse.3x.html">curs_mouse(3x)</A></STRONG>,   <STRONG><A HREF="curs_move.3x.html">curs_move(3x)</A></STRONG>,   <STRONG><A HREF="curs_refresh.3x.html">curs_refresh(3x)</A></STRONG>,   <STRONG>re-</STRONG>
 378        <STRONG><A HREF="resizeterm.3x.html">sizeterm(3x)</A></STRONG>.
 379
 380        Comparable  functions in the wide-character (ncursesw) li-
 381        brary are described in <STRONG><A HREF="curs_get_wch.3x.html">curs_get_wch(3x)</A></STRONG>.
 382
 383
 384
 385                                                          <STRONG><A HREF="curs_getch.3x.html">curs_getch(3x)</A></STRONG>
 386 </PRE>
 387 <div class="nav">
 388 <ul>
 389 <li><a href="#h2-NAME">NAME</a></li>
 390 <li><a href="#h2-SYNOPSIS">SYNOPSIS</a></li>
 391 <li><a href="#h2-DESCRIPTION">DESCRIPTION</a>
 392 <ul>
 393 <li><a href="#h3-Reading-characters">Reading characters</a></li>
 394 <li><a href="#h3-Keypad-mode">Keypad mode</a></li>
 395 <li><a href="#h3-Ungetting-characters">Ungetting characters</a></li>
 396 <li><a href="#h3-Predefined-key-codes">Predefined key-codes</a></li>
 397 <li><a href="#h3-Testing-key-codes">Testing key-codes</a></li>
 398 </ul>
 399 </li>
 400 <li><a href="#h2-RETURN-VALUE">RETURN VALUE</a></li>
 401 <li><a href="#h2-NOTES">NOTES</a></li>
 402 <li><a href="#h2-PORTABILITY">PORTABILITY</a></li>
 403 <li><a href="#h2-SEE-ALSO">SEE ALSO</a></li>
 404 </ul>
 405 </div>
 406 </BODY>
 407 </HTML>