curs_get_wstr 3x 2024-06-22 ncurses 6.5 Library calls

curs_get_wstr(3x)                Library calls               curs_get_wstr(3x)


       get_wstr,  getn_wstr,  wget_wstr,  wgetn_wstr, mvget_wstr, mvgetn_wstr,
       mvwget_wstr, mvwgetn_wstr - get a wide-character string from  a  curses
       terminal keyboard


       #include <curses.h>

       int get_wstr(wint_t * wstr);
       int wget_wstr(WINDOW * win, wint_t * wstr);
       int mvget_wstr(int y, int x, wint_t * wstr);
       int mvwget_wstr(WINDOW * win, int y, int x, wint_t * wstr);

       int getn_wstr(wint_t * wstr, int n);
       int wgetn_wstr(WINDOW * win, wint_t * wstr, int n);
       int mvgetn_wstr(int y, int x, wint_t * wstr, int n);
       int mvwgetn_wstr(WINDOW * win, int y, int x, wint_t * wstr, int n);


       The  function  wgetn_wstr  is  equivalent  to  a  series  of  calls  to
       wget_wch(3x) until a newline or carriage return terminates the series:

       o   The terminating character is not included in the returned string.

       o   An end-of-file condition is represented  by  WEOF,  as  defined  in

       o   In  all  instances,  the  end of the string is terminated by a null

       o   The function stores the result in the area pointed to by  the  wstr

       o   The function reads at most n characters, thus preventing a possible
           overflow of the input buffer.

           Any attempt to enter more characters (other  than  the  terminating
           newline or carriage return) causes a beep.

           Function keys also cause a beep and are ignored.

       The user's erase and kill characters are interpreted:

       o   The  erase  character (e.g., ^H) erases the character at the end of
           the buffer, moving the cursor to the left.

           If keypad mode is on for the window, KEY_LEFT and KEY_BACKSPACE are
           both considered equivalent to the user's erase character.

       o   The kill character (e.g., ^U) erases the entire buffer, leaving the
           cursor at the beginning of the buffer.

       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 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


       All  of  these  functions  return  the  integer  OK   upon   successful
       completion.  If unsuccessful, they return ERR.

       X/Open defines no error conditions.

       In this implementation, these functions return ERR

       o   if the window pointer is null,

       o   if its timeout expires without having any data, or

       o   if the associated call to wget_wch failed.

       Functions  prefixed with "mv" first perform cursor movement and fail if
       the position (y, x) is outside the window boundaries.


       Any of these functions other than wgetn_wstr may be macros.

       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.


       X/Open Curses, Issue 4 describes  these  functions.   It  specifies  no
       error conditions for them.

       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

       o   For  analogy  with  wgetnstr,  ncurses  6.2  uses a limit (based on

       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.


       curs_getstr(3x) describes comparable functions of the  ncurses  library
       in its non-wide-character configuration.

       curses(3x), curs_get_wch(3x)

ncurses 6.5                       2024-06-22                 curs_get_wstr(3x)