curs_get_wstr 3x 2023-07-29 ncurses 6.4 Library calls

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




NAME

       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

       #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

       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
           <wchar.h>.

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

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

       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 (typi-
       cally 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 func-
       tions, respectively, except that the *n_* versions read at most n char-
       acters, letting the application prevent overflow of the input buffer.


NOTES

       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, 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.  may be macros.


RETURN VALUE

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

       X/Open defines no error conditions.

       In this implementation, these functions return an error

       o   if the window pointer is null, or

       o   if its timeout expires without having any data.

       o   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

       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 termi-
       nating 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 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.


SEE ALSO

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



ncurses 6.4                       2023-07-29                 curs_get_wstr(3x)