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| <TITLE>curs_getch 3x</TITLE> |
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| <H1>curs_getch 3x</H1> |
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| <PRE> |
| <!-- Manpage converted by man2html 3.0.1 --> |
| <STRONG><A HREF="curs_getch.3x.html">curs_getch(3x)</A></STRONG> <STRONG><A HREF="curs_getch.3x.html">curs_getch(3x)</A></STRONG> |
| |
| |
| |
| |
| </PRE> |
| <H2>NAME</H2><PRE> |
| <STRONG>getch</STRONG>, <STRONG>wgetch</STRONG>, <STRONG>mvgetch</STRONG>, <STRONG>mvwgetch</STRONG>, <STRONG>ungetch</STRONG>, <STRONG>has_key</STRONG> - get |
| (or push back) characters from <STRONG>curses</STRONG> terminal keyboard |
| |
| |
| </PRE> |
| <H2>SYNOPSIS</H2><PRE> |
| <STRONG>#include</STRONG> <STRONG><curses.h></STRONG> |
| |
| <STRONG>int</STRONG> <STRONG>getch(void);</STRONG> |
| <STRONG>int</STRONG> <STRONG>wgetch(WINDOW</STRONG> <STRONG>*win);</STRONG> |
| <STRONG>int</STRONG> <STRONG>mvgetch(int</STRONG> <STRONG>y,</STRONG> <STRONG>int</STRONG> <STRONG>x);</STRONG> |
| <STRONG>int</STRONG> <STRONG>mvwgetch(WINDOW</STRONG> <STRONG>*win,</STRONG> <STRONG>int</STRONG> <STRONG>y,</STRONG> <STRONG>int</STRONG> <STRONG>x);</STRONG> |
| <STRONG>int</STRONG> <STRONG>ungetch(int</STRONG> <STRONG>ch);</STRONG> |
| <STRONG>int</STRONG> <STRONG>has_key(int</STRONG> <STRONG>ch);</STRONG> |
| |
| |
| </PRE> |
| <H2>DESCRIPTION</H2><PRE> |
| The <STRONG>getch</STRONG>, <STRONG>wgetch</STRONG>, <STRONG>mvgetch</STRONG> and <STRONG>mvwgetch</STRONG>, routines read a |
| character from the window. In no-delay mode, if no input |
| is waiting, the value <STRONG>ERR</STRONG> is returned. In delay mode, the |
| program waits until the system passes text through to the |
| program. Depending on the setting of <STRONG>cbreak</STRONG>, this is af- |
| ter one character (cbreak mode), or after the first new- |
| line (nocbreak mode). In half-delay mode, the program |
| waits until a character is typed or the specified timeout |
| has been reached. |
| |
| Unless <STRONG>noecho</STRONG> has been set, then the character will also |
| be echoed into the designated window according to the fol- |
| lowing rules: If the character is the current erase char- |
| acter, left arrow, or backspace, the cursor is moved one |
| space to the left and that screen position is erased as if |
| <STRONG>delch</STRONG> had been called. If the character value is any oth- |
| er <STRONG>KEY_</STRONG> define, the user is alerted with a <STRONG>beep</STRONG> call. |
| Otherwise the character is simply output to the screen. |
| |
| If the window is not a pad, and it has been moved or modi- |
| fied since the last call to <STRONG>wrefresh</STRONG>, <STRONG>wrefresh</STRONG> will be |
| called before another character is read. |
| |
| If <STRONG>keypad</STRONG> is <STRONG>TRUE</STRONG>, and a function key is pressed, the to- |
| ken for that function key is returned instead of the raw |
| characters. Possible function keys are defined in <STRONG><curs-</STRONG> |
| <STRONG>es.h></STRONG> as macros with values outside the range of 8-bit |
| characters whose names begin with <STRONG>KEY_</STRONG>. Thus, a variable |
| intended to hold the return value of a function key must |
| be of short size or larger. |
| |
| When a character that could be the beginning of a function |
| key is received (which, on modern terminals, means an es- |
| cape character), <STRONG>curses</STRONG> sets a timer. If the remainder of |
| the sequence does not come in within the designated time, |
| the character is passed through; otherwise, the function |
| key value is returned. For this reason, many terminals |
| experience a delay between the time a user presses the es- |
| cape key and the escape is returned to the program. |
| |
| The <STRONG>ungetch</STRONG> routine places <EM>ch</EM> back onto the input queue to |
| be returned by the next call to <STRONG>wgetch</STRONG>. There is just one |
| input queue for all windows. |
| |
| |
| <STRONG>Function</STRONG> <STRONG>Keys</STRONG> |
| The following function keys, defined in <STRONG><curses.h></STRONG>, might |
| be returned by <STRONG>getch</STRONG> if <STRONG>keypad</STRONG> has been enabled. Note |
| that not all of these are necessarily supported on any |
| particular terminal. |
| |
| |
| <EM>Name</EM> <EM>Key</EM> <EM>name</EM> |
| KEY_BREAK Break key |
| KEY_DOWN The four arrow keys ... |
| KEY_UP |
| KEY_LEFT |
| KEY_RIGHT |
| KEY_HOME Home key (upward+left arrow) |
| KEY_BACKSPACE Backspace |
| KEY_F0 Function keys; space for 64 keys |
| is reserved. |
| KEY_F(<EM>n</EM>) For 0 <= <EM>n</EM> <= 63 |
| KEY_DL Delete line |
| KEY_IL Insert line |
| KEY_DC Delete character |
| KEY_IC Insert char or enter insert mode |
| KEY_EIC Exit insert char mode |
| KEY_CLEAR Clear screen |
| KEY_EOS Clear to end of screen |
| KEY_EOL Clear to end of line |
| KEY_SF Scroll 1 line forward |
| KEY_SR Scroll 1 line backward (reverse) |
| KEY_NPAGE Next page |
| KEY_PPAGE Previous page |
| KEY_STAB Set tab |
| KEY_CTAB Clear tab |
| KEY_CATAB Clear all tabs |
| KEY_ENTER Enter or send |
| KEY_SRESET Soft (partial) reset |
| KEY_RESET Reset or hard reset |
| KEY_PRINT Print or copy |
| KEY_LL Home down or bottom (lower left) |
| KEY_A1 Upper left of keypad |
| KEY_A3 Upper right of keypad |
| KEY_B2 Center of keypad |
| KEY_C1 Lower left of keypad |
| KEY_C3 Lower right of keypad |
| KEY_BTAB Back tab key |
| KEY_BEG Beg(inning) key |
| KEY_CANCEL Cancel key |
| KEY_CLOSE Close key |
| KEY_COMMAND Cmd (command) key |
| KEY_COPY Copy key |
| KEY_CREATE Create key |
| KEY_END End key |
| KEY_EXIT Exit key |
| KEY_FIND Find key |
| KEY_HELP Help key |
| KEY_MARK Mark key |
| KEY_MESSAGE Message key |
| KEY_MOUSE Mouse event read |
| KEY_MOVE Move key |
| KEY_NEXT Next object key |
| KEY_OPEN Open key |
| KEY_OPTIONS Options key |
| KEY_PREVIOUS Previous object key |
| KEY_REDO Redo key |
| KEY_REFERENCE Ref(erence) key |
| KEY_REFRESH Refresh key |
| KEY_REPLACE Replace key |
| KEY_RESIZE Screen resized |
| KEY_RESTART Restart key |
| KEY_RESUME Resume key |
| |
| KEY_SAVE Save key |
| KEY_SBEG Shifted beginning key |
| KEY_SCANCEL Shifted cancel key |
| KEY_SCOMMAND Shifted command key |
| KEY_SCOPY Shifted copy key |
| KEY_SCREATE Shifted create key |
| KEY_SDC Shifted delete char key |
| KEY_SDL Shifted delete line key |
| KEY_SELECT Select key |
| KEY_SEND Shifted end key |
| KEY_SEOL Shifted clear line key |
| KEY_SEXIT Shifted exit key |
| KEY_SFIND Shifted find key |
| KEY_SHELP Shifted help key |
| KEY_SHOME Shifted home key |
| KEY_SIC Shifted input key |
| KEY_SLEFT Shifted left arrow key |
| KEY_SMESSAGE Shifted message key |
| KEY_SMOVE Shifted move key |
| KEY_SNEXT Shifted next key |
| KEY_SOPTIONS Shifted options key |
| KEY_SPREVIOUS Shifted prev key |
| KEY_SPRINT Shifted print key |
| KEY_SREDO Shifted redo key |
| KEY_SREPLACE Shifted replace key |
| KEY_SRIGHT Shifted right arrow |
| KEY_SRSUME Shifted resume key |
| KEY_SSAVE Shifted save key |
| KEY_SSUSPEND Shifted suspend key |
| KEY_SUNDO Shifted undo key |
| KEY_SUSPEND Suspend key |
| KEY_UNDO Undo key |
| |
| Keypad is arranged like this: |
| |
| |
| +-----+------+-------+ |
| | <STRONG>A1</STRONG> | <STRONG>up</STRONG> | <STRONG>A3</STRONG> | |
| +-----+------+-------+ |
| |<STRONG>left</STRONG> | <STRONG>B2</STRONG> | <STRONG>right</STRONG> | |
| +-----+------+-------+ |
| | <STRONG>C1</STRONG> | <STRONG>down</STRONG> | <STRONG>C3</STRONG> | |
| +-----+------+-------+ |
| The <STRONG>has_key</STRONG> routine takes a key value from the above list, |
| and returns TRUE or FALSE according to whether the current |
| terminal type recognizes a key with that value. Note that |
| a few values do not correspond to a real key, e.g., |
| <STRONG>KEY_RESIZE</STRONG> and <STRONG>KEY_MOUSE</STRONG>. See <STRONG><A HREF="resizeterm.3x.html">resizeterm(3x)</A></STRONG> for more de- |
| tails about <STRONG>KEY_RESIZE</STRONG>, and <STRONG><A HREF="curs_mouse.3x.html">curs_mouse(3x)</A></STRONG> for a discus- |
| sion of <STRONG>KEY_MOUSE</STRONG>. |
| |
| |
| |
| </PRE> |
| <H2>RETURN VALUE</H2><PRE> |
| All routines return the integer <STRONG>ERR</STRONG> upon failure and an |
| integer value other than <STRONG>ERR</STRONG> (<STRONG>OK</STRONG> in the case of ungetch()) |
| upon successful completion. |
| |
| <STRONG>ungetch</STRONG> |
| returns an error if there is no more room in |
| the FIFO. |
| |
| <STRONG>wgetch</STRONG> |
| returns an error if the window pointer is |
| null, or if its timeout expires without having |
| any data. |
| |
| |
| </PRE> |
| <H2>NOTES</H2><PRE> |
| Use of the escape key by a programmer for a single charac- |
| ter function is discouraged, as it will cause a delay of |
| up to one second while the keypad code looks for a follow- |
| ing function-key sequence. |
| |
| Note that some keys may be the same as commonly used con- |
| trol keys, e.g., <STRONG>KEY_ENTER</STRONG> versus control/M, <STRONG>KEY_BACKSPACE</STRONG> |
| versus control/H. Some curses implementations may differ |
| according to whether they treat these control keys spe- |
| cially (and ignore the terminfo), or use the terminfo def- |
| initions. <STRONG>Ncurses</STRONG> uses the terminfo definition. If it |
| says that <STRONG>KEY_ENTER</STRONG> is control/M, <STRONG>getch</STRONG> will return |
| <STRONG>KEY_ENTER</STRONG> when you press control/M. |
| |
| When using <STRONG>getch</STRONG>, <STRONG>wgetch</STRONG>, <STRONG>mvgetch</STRONG>, or <STRONG>mvwgetch</STRONG>, nocbreak |
| mode (<STRONG>nocbreak</STRONG>) and echo mode (<STRONG>echo</STRONG>) should not be used at |
| the same time. Depending on the state of the tty driver |
| when each character is typed, the program may produce un- |
| desirable results. |
| |
| Note that <STRONG>getch</STRONG>, <STRONG>mvgetch</STRONG>, and <STRONG>mvwgetch</STRONG> may be macros. |
| |
| Historically, the set of keypad macros was largely defined |
| by the extremely function-key-rich keyboard of the AT&T |
| 7300, aka 3B1, aka Safari 4. Modern personal computers |
| usually have only a small subset of these. IBM PC-style |
| consoles typically support little more than <STRONG>KEY_UP</STRONG>, |
| <STRONG>KEY_DOWN</STRONG>, <STRONG>KEY_LEFT</STRONG>, <STRONG>KEY_RIGHT</STRONG>, <STRONG>KEY_HOME</STRONG>, <STRONG>KEY_END</STRONG>, |
| <STRONG>KEY_NPAGE</STRONG>, <STRONG>KEY_PPAGE</STRONG>, and function keys 1 through 12. The |
| Ins key is usually mapped to <STRONG>KEY_IC</STRONG>. |
| |
| |
| </PRE> |
| <H2>PORTABILITY</H2><PRE> |
| The *get* functions are described in the XSI Curses stan- |
| dard, Issue 4. They read single-byte characters only. |
| The standard specifies that they return <STRONG>ERR</STRONG> on failure, |
| but specifies no error conditions. |
| |
| The echo behavior of these functions on input of <STRONG>KEY_</STRONG> or |
| backspace characters was not specified in the SVr4 docu- |
| mentation. This description is adopted from the XSI Curs- |
| es standard. |
| |
| The behavior of <STRONG>getch</STRONG> and friends in the presence of han- |
| dled signals is unspecified in the SVr4 and XSI Curses |
| documentation. Under historical curses implementations, |
| it varied depending on whether the operating system's im- |
| plementation of handled signal receipt interrupts a |
| <STRONG><A HREF="read.2.html">read(2)</A></STRONG> call in progress or not, and also (in some imple- |
| mentations) depending on whether an input timeout or non- |
| blocking mode has been set. |
| |
| Programmers concerned about portability should be prepared |
| for either of two cases: (a) signal receipt does not in- |
| terrupt <STRONG>getch</STRONG>; (b) signal receipt interrupts <STRONG>getch</STRONG> and |
| causes it to return ERR with <STRONG>errno</STRONG> set to <STRONG>EINTR</STRONG>. Under |
| the <STRONG>ncurses</STRONG> implementation, handled signals never inter- |
| rupt <STRONG>getch</STRONG>. |
| |
| The <STRONG>has_key</STRONG> function is unique to <STRONG>ncurses</STRONG>. We recommend |
| that any code using it be conditionalized on the <STRONG>NCURS-</STRONG> |
| <STRONG>ES_VERSION</STRONG> feature macro. |
| |
| |
| </PRE> |
| <H2>SEE ALSO</H2><PRE> |
| <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_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><A HREF="resizeterm.3x.html">resizeterm(3x)</A></STRONG>. |
| |
| Comparable functions in the wide-character (ncursesw) li- |
| brary are described in <STRONG><A HREF="curs_get_wch.3x.html">curs_get_wch(3x)</A></STRONG>. |
| |
| |
| |
| <STRONG><A HREF="curs_getch.3x.html">curs_getch(3x)</A></STRONG> |
| </PRE> |
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