- get_wstr, getn_wstr, wget_wstr, wgetn_wstr, mvget_wstr,
- mvgetn_wstr, mvwget_wstr, mvwgetn_wstr - get an array of
- wide characters from a curses terminal keyboard
+ get_wstr, getn_wstr, wget_wstr, wgetn_wstr, mvget_wstr, mvgetn_wstr,
+ mvwget_wstr, mvwgetn_wstr - get an array of wide characters from a
+ curses terminal keyboard
- The effect of get_wstr is as though a series of calls to
- get_wch were made, until a newline, other end-of-line, or
- end-of-file condition is processed. An end-of-file condi-
- tion is represented by WEOF, as defined in <wchar.h>. The
- newline and end-of-line conditions are represented by the
- \nwchar_t value. In all instances, the end of the string
- is terminated by a null wchar_t. The routine places re-
- sulting values in the area pointed to by wstr.
+ The effect of get_wstr is as though a series of calls to get_wch(3x)
+ were made, until a newline, other end-of-line, or end-of-file condition
+ is processed. An end-of-file condition is represented by WEOF, as de-
+ fined in <wchar.h>. The newline and end-of-line conditions are repre-
+ sented by the \nwchar_t value. In all instances, the end of the
+ string is terminated by a null wchar_t. The routine places resulting
+ values in the area pointed to by wstr.
- The user's erase and kill characters are interpreted. If
- keypad mode is on for the window, KEY_LEFT and
- KEY_BACKSPACE are both considered equivalent to the user's
- kill character.
+ The user's erase and kill characters are interpreted. If keypad mode
+ is on for the window, KEY_LEFT and KEY_BACKSPACE are both considered
+ equivalent to the user's kill character.
- Characters input are echoed only if echo is currently on.
- In that case, backspace is echoed as deletion of the pre-
- vious character (typically a left motion).
+ Characters input are echoed only if echo is currently on. In that
+ case, backspace is echoed as deletion of the previous character (typi-
+ cally a left motion).
- The effect of wget_wstr is as though a series of calls to
- wget_wch were made.
+ The effect of wget_wstr is as though a series of calls to wget_wch were
+ made.
- The effect of mvget_wstr is as though a call to move and
- then a series of calls to get_wch were made.
+ The effect of mvget_wstr is as though a call to move and then a series
+ of calls to get_wch were made.
- The effect of mvwget_wstr is as though a call to wmove and
- then a series of calls to wget_wch were made.
+ The effect of mvwget_wstr is as though a call to wmove and then a se-
+ ries of calls to wget_wch were made.
- The getn_wstr, mvgetn_wstr, mvwgetn_wstr, and wgetn_wstr
- functions are identical to the get_wstr, mvget_wstr,
- mvwget_wstr, and wget_wstr functions, respectively, except
- that the *n_* versions read at most n characters, letting
- the application prevent overflow of the input buffer.
+ The getn_wstr, mvgetn_wstr, mvwgetn_wstr, and wgetn_wstr functions are
+ identical to the get_wstr, mvget_wstr, mvwget_wstr, and wget_wstr func-
+ tions, respectively, except that the *n_* versions read at most n char-
+ acters, letting the application prevent overflow of the input buffer.
- Using get_wstr, mvget_wstr, mvwget_wstr, or wget_wstr to
- read a line that overflows the array pointed to by wstr
- causes undefined results. The use of getn_wstr,
- mvgetn_wstr, mvwgetn_wstr, or wgetn_wstr, respectively, is
- recommended.
+ Using get_wstr, mvget_wstr, mvwget_wstr, or wget_wstr to read a line
+ that overflows the array pointed to by wstr causes undefined results.
+ The use of getn_wstr, mvgetn_wstr, mvwgetn_wstr, or wgetn_wstr, respec-
+ tively, is recommended.
- These functions cannot return KEY_ values because there is
- no way to distinguish a KEY_ value from a valid wchar_t
- value.
+ These functions cannot return KEY_ values because there is no way to
+ distinguish a KEY_ value from a valid wchar_t value.
All of these routines except wgetn_wstr may be macros.
- All of these functions return OK upon successful comple-
- tion. Otherwise, they return ERR.
+ All of these functions return OK upon successful completion. Other-
+ wise, they return ERR.
- Functions using a window parameter return an error if it
- is null.
+ Functions using a window parameter return an error if it is null.
wgetn_wstr
- returns an error if the associated call to
- wget_wch failed.
+ returns an error if the associated call to wget_wch failed.
- 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.
+ Functions with a "mv" prefix first perform a cursor movement using
+ wmove, and return an error if the position is outside the window, or if
+ the window pointer is null.
- These functions are described in The Single Unix Specifi-
- cation, Version 2. No error conditions are defined. This
- implementation returns ERR if the window pointer is null,
- or if the lower-level wget_wch call returns an ERR. In
- the latter case, an ERR return without other data is
- treated as an end-of-file condition, and the returned ar-
- ray contains a WEOF followed by a null wchar_t.
+ These functions are described in The Single Unix Specification, Version
+ 2. No error conditions are defined. This implementation returns ERR
+ if the window pointer is null, or if the lower-level wget_wch call re-
+ turns an ERR. In the latter case, an ERR return without other data is
+ treated as an end-of-file condition, and the returned array contains a
+ WEOF followed by a null wchar_t.
- X/Open curses documents these functions to pass an array
- of wchar_t, but all of the vendors implement this using
- wint_t.
+ X/Open curses documented these functions to pass an array of wchar_t in
+ 1997, but that was an error because of this part of the description:
+
+ The effect of get_wstr() is as though a series of calls to
+ get_wch() were made, until a newline character, end-of-line
+ character, or end-of-file character is processed.
+
+ The latter function get_wch() can return a negative value, while
+ wchar_t is a unsigned type. All of the vendors implement this using
+ wint_t, following the standard.
+
+ X/Open Curses, Issue 7 (2009) is unclear regarding whether the termi-
+ nating nullwchar_t value is counted in the length parameter n. X/Open
+ Curses, Issue 7 revised the corresponding description of wgetnstr to
+ address this issue. The unrevised description of wget_nwstr can be in-
+ terpreted either way. This implementation counts the terminator in the
+ length.
+
+ X/Open Curses does not specify what happens if the length n is nega-
+ tive.
+
+ o For analogy with wgetnstr, ncurses 6.2 uses a limit (based on
+ LINE_MAX).
+
+ o Some other implementations (such as Solaris xcurses) do the same,
+ while others (PDCurses) do not allow this.
+
+ o NetBSD 7 curses imitates ncurses 6.1 in this regard, treating a -1
+ as an indefinite number of characters.