curs_get_wstr(3x) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | NOTES | RETURN VALUE | PORTABILITY | SEE ALSO | COLOPHON

curs_get_wstr(3X)                                      curs_get_wstr(3X)

NAME         top

       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

SYNOPSIS         top

       #include <curses.h>

       int get_wstr(wint_t *wstr);
       int getn_wstr(wint_t *wstr, int n);
       int wget_wstr(WINDOW *win, wint_t *wstr);
       int wgetn_wstr(WINDOW *win, wint_t *wstr, int n);

       int mvget_wstr(int y, int x, wint_t *wstr);
       int mvgetn_wstr(int y, int x, wint_t *wstr, int n);
       int mvwget_wstr(WINDOW *win, int y, int x, wint_t *wstr);
       int mvwgetn_wstr(WINDOW *win, int y, int x, wint_t *wstr, int n);

DESCRIPTION         top

       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 defined in <wchar.h>.  The newline and
       end-of-line conditions are represented by the \n wchar_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.

       Characters input are echoed only if echo is currently on.  In
       that case, backspace is echoed as deletion of the previous
       character (typically a left motion).

       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 mvwget_wstr is as though a call to wmove and then a
       series 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.

NOTES         top

       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.

       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.

RETURN VALUE         top

       All of these functions return OK upon successful completion.
       Otherwise, they return ERR.

       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.

       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.

PORTABILITY         top

       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 returns 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 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
       terminating null wchar_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 interpreted either way.  This implementation
       counts the terminator in the length.

       X/Open Curses does not specify what happens if the length n is
       negative.

       •   For analogy with wgetnstr, ncurses 6.2 uses a limit (based on
           LINE_MAX).

       •   Some other implementations (such as Solaris xcurses) do the
           same, while others (PDCurses) do not allow this.

       •   NetBSD 7 curses imitates ncurses 6.1 in this regard, treating
           a -1 as an indefinite number of characters.

SEE ALSO         top

       Functions: curses(3X), curs_get_wch(3X), curs_getstr(3X).

COLOPHON         top

       This page is part of the ncurses (new curses) project.
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       ⟨git://ncurses.scripts.mit.edu/ncurses.git⟩ on 2021-08-27.  (At
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                                                       curs_get_wstr(3X)