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
@@ -76,14 +76,24 @@
waits until a character is typed or the specified timeout
has been reached.
- Unless noecho 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
- delch had been called. If the character value is any oth-
- er KEY_ define, the user is alerted with a beep call.
- Otherwise the character is simply output to the screen.
+ If echo is enabled, and the window is not a pad, then the
+ character will also be echoed into the designated window
+ according to the following rules:
+
+ o If the character is the current erase character, left
+ arrow, or backspace, the cursor is moved one space to
+ the left and that screen position is erased as if
+ delch had been called.
+
+ o If the character value is any other KEY_ define, the
+ user is alerted with a beep call.
+
+ o If the character is a carriage-return, and if nl is
+ enabled, it is translated to a line-feed after echo-
+ ing.
+
+ o 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 wrefresh, wrefresh will be
@@ -93,7 +103,7 @@
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
+ 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.
@@ -110,14 +120,16 @@
be returned by the next call to wgetch. There is just one
input queue for all windows.
- FunctionKeys
+
+
The following function keys, defined in <curses.h>, might
be returned by getch if keypad has been enabled. Note
that not all of these are necessarily supported on any
particular terminal.
-
NameKeyname
+ -------------------------------------------------
KEY_BREAK Break key
KEY_DOWN The four arrow keys ...
KEY_UP
@@ -168,6 +180,7 @@
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
@@ -178,7 +191,6 @@
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
@@ -224,7 +236,7 @@
| C1 | down | C3 |
+-----+------+-------+
The has_key routine takes a key value from the above list,
- and returns TRUE or FALSE according to whether the current
+ 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.,
KEY_RESIZE and KEY_MOUSE. See resizeterm(3x) for more de-
@@ -233,23 +245,25 @@
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 an error if there is no more room in
- the FIFO.
+ 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.
- wgetch
- returns an error if the window pointer is
- null, or if its timeout expires without having
- any data.
+ 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
up to one second while the keypad code looks for a follow-
@@ -264,6 +278,22 @@
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
+ 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-
+ 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
+ carriage-return or line-feed, and finally
+
+ o "Enter or send" is the standard description for this
+ key.
+
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
@@ -283,7 +313,7 @@
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,
@@ -299,7 +329,7 @@
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-
+ 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.
@@ -316,21 +346,32 @@