X-Git-Url: http://ncurses.scripts.mit.edu/?a=blobdiff_plain;f=doc%2Fhtml%2Fman%2Fcurs_getch.3x.html;h=d19c4b87454eea094ac47dad7dec1e085756245e;hb=8e397cccba0aad135cb9a8a353756f4273a7cdf6;hp=1df5dd04f0b12e5ca3879ce56fc97a376b80706f;hpb=b9a2bd87a73d976d1c916815e2d370bf1090d1b2;p=ncurses.git diff --git a/doc/html/man/curs_getch.3x.html b/doc/html/man/curs_getch.3x.html index 1df5dd04..d19c4b87 100644 --- a/doc/html/man/curs_getch.3x.html +++ b/doc/html/man/curs_getch.3x.html @@ -1,7 +1,7 @@ @@ -46,14 +46,12 @@ - -
+
getch, wgetch, mvgetch, mvwgetch, ungetch, has_key - get (or push back) characters from curses terminal keyboard --
+
#include <curses.h> int getch(void); @@ -64,11 +62,9 @@ int has_key(int ch); --
+
--
+
The getch, wgetch, mvgetch and mvwgetch, routines read a character from the window. In no-delay mode, if no input is waiting, the value ERR is returned. In delay mode, the @@ -103,15 +99,22 @@ called before another character is read. --
+
If keypad is TRUE, 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 <curs- - es.h> as macros with values outside the range of 8-bit - characters whose names begin with KEY_. Thus, a variable - intended to hold the return value of a function key must - be of short size or larger. + characters: + + o The predefined function keys are listed in <curses.h> + as macros with values outside the range of 8-bit char- + acters. Their names begin with KEY_. + + o Other (user-defined) function keys which may be de- + fined using define_key(3x) have no names, but also are + expected to have values outside the range of 8-bit + characters. + + 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- @@ -122,20 +125,35 @@ experience a delay between the time a user presses the es- cape key and the escape is returned to the program. + In ncurses, the timer normally expires after the value in + ESCDELAY (see curs_variables(3x)). If notimeout is TRUE, + the timer does not expire; it is an infinite (or very + large) value. Because function keys usually begin with an + escape character, the terminal may appear to hang in no- + timeout mode after pressing the escape key until another + key is pressed. --
+ +
The ungetch routine places ch back onto the input queue to be returned by the next call to wgetch. There is just one input queue for all windows. --
- The following special keys, defined in <curses.h>, may be - returned by getch if keypad has been enabled. Not all of - these are necessarily supported on any particular termi- - nal. +
+ The following special keys are defined in <curses.h>. + + o Except for the special case KEY_RESIZE, it is neces- + sary to enable keypad for getch to return these codes. + + o Not all of these are necessarily supported on any par- + ticular terminal. + + o The naming convention may seem obscure, with some ap- + parent misspellings (such as "RSUME" for "resume"). + The names correspond to the long terminfo capability + names for the keys, and were defined long ago, in the + 1980s. Name Key name ------------------------------------------------- @@ -161,6 +179,7 @@ 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 @@ -186,7 +205,6 @@ 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 @@ -227,6 +245,7 @@ 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 @@ -243,154 +262,149 @@ +-----+------+-------+ | C1 | down | C3 | +-----+------+-------+ - A few of these predefined values do not correspond to a + A few of these predefined values do not correspond to a real key: - o KEY_RESIZE is returned when the SIGWINCH signal has - been detected (see curs_initscr(3x) and resizeterm(3x)). - This code is returned whether or not keypad has been + o KEY_RESIZE is returned when the SIGWINCH signal has + been detected (see initscr(3x) and resizeterm(3x)). + This code is returned whether or not keypad has been enabled. - o KEY_MOUSE is returned for mouse-events (see + o KEY_MOUSE is returned for mouse-events (see curs_mouse(3x)). This code relies upon whether or not - keypad(3x) has been enabled, because (e.g., with xterm - mouse prototocol) ncurses must read escape sequences, + keypad(3x) has been enabled, because (e.g., with xterm + mouse prototocol) ncurses must read escape sequences, just like a function key. --
- The has_key routine takes a key-code value from the above - list, and returns TRUE or FALSE according to whether the +
+ The has_key routine takes a key-code value from the above + list, and returns TRUE or FALSE according to whether the current terminal type recognizes a key with that value. The library also supports these extensions: define_key - defines a key-code for a given string (see de- + defines a key-code for a given string (see de- fine_key(3x)). key_defined - checks if there is a key-code defined for a given + checks if there is a key-code defined for a given string (see key_defined(3x)). --
- All routines return the integer ERR upon failure and an - integer value other than ERR (OK in the case of ungetch()) +
+ All routines return the integer ERR upon failure and an + integer value other than ERR (OK in the case of ungetch) upon successful completion. ungetch returns ERR if there is no more room in the FIFO. wgetch - returns ERR if the window pointer is null, or if - its timeout expires without having any data. + returns ERR if the window pointer is null, or if + its timeout expires without having any data, or if + the execution was interrupted by a signal (errno + will be set to EINTR). - Functions with a "mv" prefix first perform a cursor move- - ment using wmove, and return an error if the position is + Functions with a "mv" prefix first perform a cursor move- + ment using wmove, and return an error if the position is outside the window, or if the window pointer is null. --
+
Use of the escape key by a programmer for a single charac- - ter function is discouraged, as it will cause a delay of + 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. - Some keys may be the same as commonly used control keys, - e.g., KEY_ENTER versus control/M, KEY_BACKSPACE versus + Some keys may be the same as commonly used control keys, + e.g., KEY_ENTER versus control/M, KEY_BACKSPACE versus control/H. Some curses implementations may differ accord- - ing to whether they treat these control keys specially - (and ignore the terminfo), or use the terminfo defini- - tions. Ncurses uses the terminfo definition. If it says - that KEY_ENTER is control/M, getch will return KEY_ENTER + ing to whether they treat these control keys specially + (and ignore the terminfo), or use the terminfo defini- + tions. Ncurses uses the terminfo definition. If it says + that KEY_ENTER is control/M, getch will return KEY_ENTER when you press control/M. - Generally, KEY_ENTER denotes the character(s) sent by the + Generally, KEY_ENTER denotes the character(s) sent by the Enter key on the numeric keypad: o the terminal description lists the most useful keys, - o the Enter key on the regular keyboard is already han- + o the Enter key on the regular keyboard is already han- dled by the standard ASCII characters for carriage-re- turn and line-feed, - o depending on whether nl or nonl was called, pressing - "Enter" on the regular keyboard may return either a + o depending on whether nl or nonl was called, pressing + "Enter" on the regular keyboard may return either a carriage-return or line-feed, and finally - o "Enter or send" is the standard description for this + o "Enter or send" is the standard description for this key. - When using getch, wgetch, mvgetch, or mvwgetch, nocbreak + When using getch, wgetch, mvgetch, or mvwgetch, nocbreak mode (nocbreak) and echo mode (echo) 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- + 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 getch, mvgetch, and mvwgetch 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 KEY_UP, - KEY_DOWN, KEY_LEFT, KEY_RIGHT, KEY_HOME, KEY_END, + 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 KEY_UP, + KEY_DOWN, KEY_LEFT, KEY_RIGHT, KEY_HOME, KEY_END, KEY_NPAGE, KEY_PPAGE, and function keys 1 through 12. The Ins key is usually mapped to KEY_IC. --
- 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 ERR on failure, +
+ 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 ERR on failure, but specifies no error conditions. - The echo behavior of these functions on input of KEY_ or - backspace characters was not specified in the SVr4 docu- + The echo behavior of these functions on input of KEY_ or + backspace characters was not specified in the SVr4 docu- mentation. This description is adopted from the XSI Curs- es standard. - The behavior of getch 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 - read(2) call in progress or not, and also (in some imple- - mentations) depending on whether an input timeout or non- + The behavior of getch 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 + read(2) call in progress or not, and also (in some imple- + mentations) depending on whether an input timeout or non- blocking mode has been set. KEY_MOUSE is mentioned in XSI Curses, along with a few re- lated terminfo capabilities, but no higher-level functions - use the feature. The implementation in ncurses is an ex- + use the feature. The implementation in ncurses is an ex- tension. - KEY_RESIZE is an extension first implemented for ncurses. + KEY_RESIZE is an extension first implemented for ncurses. NetBSD curses later added this extension. Programmers concerned about portability should be prepared - for either of two cases: (a) signal receipt does not in- - terrupt getch; (b) signal receipt interrupts getch and - causes it to return ERR with errno set to EINTR. Under - the ncurses implementation, handled signals never inter- - rupt getch. - - The has_key function is unique to ncurses. We recommend - that any code using it be conditionalized on the NCURS- + for either of two cases: (a) signal receipt does not in- + terrupt getch; (b) signal receipt interrupts getch and + causes it to return ERR with errno set to EINTR. + + The has_key function is unique to ncurses. We recommend + that any code using it be conditionalized on the NCURS- ES_VERSION feature macro. --
+
curses(3x), curs_inopts(3x), curs_outopts(3x), - curs_mouse(3x), curs_move(3x), curs_refresh(3x), re- - sizeterm(3x). + curs_mouse(3x), curs_move(3x), curs_refresh(3x), + curs_variables(3x), resizeterm(3x). - Comparable functions in the wide-character (ncursesw) li- + Comparable functions in the wide-character (ncursesw) li- brary are described in curs_get_wch(3x).