CURSES_INPUT(3) NetBSD Library Functions Manual CURSES_INPUT(3)
curses_input, getch, wgetch, mvgetch, mvwgetch, define_key, keyok, has_key, getnstr, wgetnstr, mvgetnstr, mvwgetnstr, getstr, wgetstr, mvgetstr, mvwgetstr, keypad, is_keypad, notimeout, timeout, wtimeout, nodelay, ungetch, set_escdelay -- curses input stream routines
Curses Library (libcurses, -lcurses)
#include <curses.h> int getch(void); int wgetch(WINDOW *win); int mvgetch(int y, int x); int mvwgetch(WINDOW *win, int y, int x); int keyok(int key_symbol, bool flag); int has_key(int key_symbol); int define_key(char *sequence, int key_symbol); int getnstr(char *str, int limit); int wgetnstr(WINDOW *win, char *str, int limit); int mvgetnstr(int y, int x, char *str, int limit); int mvwgetnstr(WINDOW *win, int y, int x, char *str, int limit); int getstr(char *str); int wgetstr(WINDOW *win, char *str); int mvgetstr(int y, int x, char *str); int mvwgetstr(WINDOW *win, int y, int x, char *str); int keypad(WINDOW *win, boolf flag); bool is_keypad(const WINDOW *win); int notimeout(WINDOW *win, boolf flag); int timeout(int delay); int wtimeout(WINDOW *win, int delay); int nodelay(WINDOW *win, boolf flag); int ungetch(int c); int set_escdelay(int escdelay); extern int ESCDELAY;
These functions read characters and strings from the window input file descriptor. The getch() function reads a character from the stdscr input file descriptor and returns it. If the keypad() flag has been set to TRUE, then getch() will assemble multi-character key sequences into key sym- bols, If the terminal is resized, getch() will return KEY_RESIZE, regard- less of the setting of keypad(). Calling getch() will cause an implicit refresh() on stdscr. The wgetch() function is the same as the getch() function, excepting that it reads from the input file descriptor associated with the window speci- fied by win. If the keypad() flag is TRUE then the assembly of specific key symbols can be disabled by using the keyok() function. If the flag is set to FALSE on a key symbol then getch() will behave as if the character sequence associated with that key symbol was not recognised and will return the component characters one at a time to the caller. The is_keypad() function returns TRUE if the keypad flag is set for the win- dow specified by win. The has_key() function takes a key value and returns TRUE if the current terminal recognises a key with that value, otherwise FALSE. Custom associations between sequences of characters and a key symbol can be made by using the define_key() function. Normally, these associations are made by the information in the terminfo(5) database but the define_key() function gives the capability to remove or add more associa- tions. If define_key() is passed a non-NULL string in sequence it will associate that sequence with the key symbol passed in key_symbol. The key symbol may be one of the ones listed below or a custom value that is application defined. It is valid to have multiple character sequences map to the same key symbol and there are no constraints on the length of the sequence allowed. The assembly of custom sequences follow the same rules for inter-character timing and so forth as the terminfo(5) derived ones. If define_key() is passed a NULL in sequence then all associations for the key symbol in key_symbol will be deleted, this includes any asso- ciations that were derived from terminfo(5). The mvgetch() and mvwgetch() functions are the same as the getch() and wgetch() functions, respectively, excepting that wmove() is called to move the cursor to the position specified by y, x before the character is read. Calling getnstr(), wgetnstr(), mvgetnstr() or mvwgetnstr() is effectively the same as calling getch() repeatedly until a newline is received or the character limit limit is reached. Once this happens the string is NULL terminated and returned in str. During input, the normal curses input key processing is performed and affects the input buffer. The mvgetnstr() function calls wmove() to move the cursor to the position given by y, x before getting the string, wgetnstr() reads the input from the designated window, mvwgetnstr() moves the cursor to the position given by y, x before getting the input from the designated window. The functions getstr(), wgetstr(), mvgetstr(), and mvwgetstr() are simi- lar to getnstr(), wgetnstr(), mvgetnstr(), and mvwgetnstr(), respec- tively, excepting that there is no limit on the number of characters that may be inserted into str. This may cause the buffer to be overflowed, so their use is not recommended. The keypad() function is used to affect how getch() processes input char- acters. If flag is set to TRUE, then getch() will scan the input stream looking for multi-character key sequences that are emitted by some termi- nal function keys. If a recognised sequence of characters is found, then getch() will collapse that sequence into an integer key symbol, as shown below. The default setting for the flag is FALSE. The notimeout() function controls whether or not getch() will wait indef- initely between characters in a multi-character key sequence or not. If flag is TRUE, then there is no timeout applied between characters com- prising a multi-character key sequence. If flag is FALSE, then the com- ponent characters of a multi-character sequence must not have an inter- character gap of more than ESCDELAY. If this timing is exceeded, then the multi-character key assembly is deemed to have failed and the charac- ters read thus far are returned one at a time when getch() is called. The default setting for the flag is FALSE. The default value of ESCDELAY is 300ms. If ESCDELAY is negative, no timeout is applied between charac- ters comprising a multi-character key sequence. The timeout() function affects the behaviour of getch() when reading a character from stdscr. If delay is negative, then getch() will block indefinitely on a read. If delay is 0, then getch() will return immedi- ately with ERR if there are no characters immediately available. If delay is a positive number, then getch() will wait for that many mil- liseconds before returning and, if no character was available, then ERR will be returned. Note that for a positive number, the timeout is only accurate to the nearest tenth of a second. Also, the maximum value of delay is 25500 milliseconds. The wtimeout() function does the same as timeout() but applies to the specified window win. The nodelay() function turns on and off blocking reads for getch(). If flag is TRUE, then getch() will not block on reads, if flag is FALSE, then reads will block. The default setting for the flag is FALSE. nodelay(win, TRUE) is equivalent to wtimeout(win, 0) and nodelay(win, FALSE) is equivalent to wtimeout(win, -1). ungetch() will convert c into an unsigned char and push that character back onto the input stream. Only one character of push-back is guaran- teed to work, more may be possible depending on system resources. The set_escdelay() function sets the ESCDELAY value of the current screen to escdelay.
The functions getch(), wgetch(), mvgetch(), and mvwgetch() will return the value of the key pressed or ERR in the case of an error or a timeout. Additionally, if keypad(TRUE) has been called on a window, then it may return one of the following values: Termcap entry getch Return Value Key Function !1 KEY_SSAVE Shift Save !2 KEY_SSUSPEND Shift Suspend !3 KEY_SUNDO Shift Undo #1 KEY_SHELP Shift Help #2 KEY_SHOME Shift Home #3 KEY_SIC Shift Insert Character #4 KEY_SLEFT Shift Left Arrow %0 KEY_REDO Redo %1 KEY_HELP Help %2 KEY_MARK Mark %3 KEY_MESSAGE Message %4 KEY_MOVE Move %5 KEY_NEXT Next Object %6 KEY_OPEN Open %7 KEY_OPTIONS Options %8 KEY_PREVIOUS Previous Object %9 KEY_PRINT Print %a KEY_SMESSAGE Shift Message %b KEY_SMOVE Shift Move %c KEY_SNEXT Shift Next Object %d KEY_SOPTIONS Shift Options %e KEY_SPREVIOUS Shift Previous Object %f KEY_SPRINT Shift Print %g KEY_SREDO Shift Redo %h KEY_SREPLACE Shift Replace %i KEY_SRIGHT Shift Right Arrow %j KEY_SRSUME Shift Resume &0 KEY_SCANCEL Shift Cancel &1 KEY_REFERENCE Reference &2 KEY_REFRESH Refresh &3 KEY_REPLACE Replace &4 KEY_RESTART Restart &5 KEY_RESUME Resume &6 KEY_SAVE Save &7 KEY_SUSPEND Suspend &8 KEY_UNDO Undo &9 KEY_SBEG Shift Begin *0 KEY_SFIND Shift Find *1 KEY_SCOMMAND Shift Command *2 KEY_SCOPY Shift Copy *3 KEY_SCREATE Shift Create *4 KEY_SDC Shift Delete Character *5 KEY_SDL Shift Delete Line *6 KEY_SELECT Select *7 KEY_SEND Shift End *8 KEY_SEOL Shift Clear to EOL *9 KEY_SEXIT Shift Exit @0 KEY_FIND Find @1 KEY_BEG Begin @2 KEY_CANCEL Cancel @3 KEY_CLOSE Close @4 KEY_COMMAND Command @5 KEY_COPY Copy @6 KEY_CREATE Create @7 KEY_END End @8 KEY_ENTER Enter @9 KEY_EXIT Exit F1 KEY_F(11) Function Key 11 F2 KEY_F(12) Function Key 12 F3 KEY_F(13) Function Key 13 F4 KEY_F(14) Function Key 14 F5 KEY_F(15) Function Key 15 F6 KEY_F(16) Function Key 16 F7 KEY_F(17) Function Key 17 F8 KEY_F(18) Function Key 18 F9 KEY_F(19) Function Key 19 FA KEY_F(20) Function Key 20 FB KEY_F(21) Function Key 21 FC KEY_F(22) Function Key 22 FD KEY_F(23) Function Key 23 FE KEY_F(24) Function Key 24 FF KEY_F(25) Function Key 25 FG KEY_F(26) Function Key 26 FH KEY_F(27) Function Key 27 FI KEY_F(28) Function Key 28 FJ KEY_F(29) Function Key 29 FK KEY_F(30) Function Key 30 FL KEY_F(31) Function Key 31 FM KEY_F(32) Function Key 32 FN KEY_F(33) Function Key 33 FO KEY_F(34) Function Key 34 FP KEY_F(35) Function Key 35 FQ KEY_F(36) Function Key 36 FR KEY_F(37) Function Key 37 FS KEY_F(38) Function Key 38 FT KEY_F(39) Function Key 39 FU KEY_F(40) Function Key 40 FV KEY_F(41) Function Key 41 FW KEY_F(42) Function Key 42 FX KEY_F(43) Function Key 43 FY KEY_F(44) Function Key 44 FZ KEY_F(45) Function Key 45 Fa KEY_F(46) Function Key 46 Fb KEY_F(47) Function Key 47 Fc KEY_F(48) Function Key 48 Fd KEY_F(49) Function Key 49 Fe KEY_F(50) Function Key 50 Ff KEY_F(51) Function Key 51 Fg KEY_F(52) Function Key 52 Fh KEY_F(53) Function Key 53 Fi KEY_F(54) Function Key 54 Fj KEY_F(55) Function Key 55 Fk KEY_F(56) Function Key 56 Fl KEY_F(57) Function Key 57 Fm KEY_F(58) Function Key 58 Fn KEY_F(59) Function Key 59 Fo KEY_F(60) Function Key 60 Fp KEY_F(61) Function Key 61 Fq KEY_F(62) Function Key 62 Fr KEY_F(63) Function Key 63 K1 KEY_A1 Upper left key in keypad K2 KEY_B2 Centre key in keypad K3 KEY_A3 Upper right key in keypad K4 KEY_C1 Lower left key in keypad K5 KEY_C3 Lower right key in keypad Km KEY_MOUSE Mouse Event k0 KEY_F0 Function Key 0 k1 KEY_F(1) Function Key 1 k2 KEY_F(2) Function Key 2 k3 KEY_F(3) Function Key 3 k4 KEY_F(4) Function Key 4 k5 KEY_F(5) Function Key 5 k6 KEY_F(6) Function Key 6 k7 KEY_F(7) Function Key 7 k8 KEY_F(8) Function Key 8 k9 KEY_F(9) Function Key 9 k; KEY_F(10) Function Key 10 kA KEY_IL Insert Line ka KEY_CATAB Clear All Tabs kB KEY_BTAB Back Tab kb KEY_BACKSPACE Backspace kC KEY_CLEAR Clear kD KEY_DC Delete Character kd KEY_DOWN Down Arrow kE KEY_EOL Clear to End Of Line kF KEY_SF Scroll Forward one line kH KEY_LL Home Down kh KEY_HOME Home kI KEY_IC Insert Character kL KEY_DL Delete Line kl KEY_LEFT Left Arrow kM KEY_EIC Exit Insert Character Mode kN KEY_NPAGE Next Page kP KEY_PPAGE Previous Page kR KEY_SR Scroll One Line Back kr KEY_RIGHT Right Arrow kS KEY_EOS Clear to End Of Screen kT KEY_STAB Set Tab kt KEY_CTAB Clear Tab ku KEY_UP Up Arrow Note that not all terminals are capable of generating all the keycodes listed above nor are terminfo entries normally configured with all the above capabilities defined. Other functions that return an int will return one of the following val- ues: OK The function completed successfully. ERR An error occurred in the function. Functions returning pointers will return NULL if an error is detected.
curses_cursor(3), curses_keyname(3), curses_refresh(3), curses_tty(3), terminfo(5)
The NetBSD Curses library complies with the X/Open Curses specification, part of the Single Unix Specification.
The keyok() and define_key() functions are implementations of extensions made by the NCurses library to the Curses standard. Portable implementa- tions should avoid the use of these functions.
The Curses package appeared in 4.0BSD. The is_keypad() and set_tabsize() functions are ncurses extension to the Curses library and was added in NetBSD 8.0. NetBSD 9.0 January 5, 2017 NetBSD 9.0
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