<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN"> <!-- * t **************************************************************************** * Copyright (c) 1998-2005,2006 Free Software Foundation, Inc. * * * * Permission is hereby granted, free of charge, to any person obtaining a * * copy of this software and associated documentation files (the * * "Software"), to deal in the Software without restriction, including * * without limitation the rights to use, copy, modify, merge, publish, * * distribute, distribute with modifications, sublicense, and/or sell * * copies of the Software, and to permit persons to whom the Software is * * furnished to do so, subject to the following conditions: * * * * The above copyright notice and this permission notice shall be included * * in all copies or substantial portions of the Software. * * * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS * * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. * * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, * * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR * * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR * * THE USE OR OTHER DEALINGS IN THE SOFTWARE. * * * * Except as contained in this notice, the name(s) of the above copyright * * holders shall not be used in advertising or otherwise to promote the * * sale, use or other dealings in this Software without prior written * * authorization. * **************************************************************************** * @Id: curs_getch.3x,v 1.30 2006/12/02 17:02:53 tom Exp @ --> <HTML> <HEAD> <TITLE>curs_getch 3x</TITLE> <link rev=made href="mailto:bug-ncurses@gnu.org"> <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"> </HEAD> <BODY> <H1>curs_getch 3x</H1> <HR> <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> <HR> <ADDRESS> Man(1) output converted with <a href="http://www.oac.uci.edu/indiv/ehood/man2html.html">man2html</a> </ADDRESS> </BODY> </HTML>