печатать форматированный вывод в окнах curses (print formatted output in curses windows)
Имя (Name)
printw, wprintw, mvprintw, mvwprintw, vwprintw, vw_printw - print
formatted output in curses windows
Синопсис (Synopsis)
#include <curses.h>
int printw(const char *fmt, ...);
int wprintw(WINDOW *win, const char *fmt, ...);
int mvprintw(int y, int x, const char *fmt, ...);
int mvwprintw(WINDOW *win, int y, int x, const char *fmt, ...);
int vw_printw(WINDOW *win, const char *fmt, va_list varglist);
/* obsolete */
int vwprintw(WINDOW *win, const char *fmt, va_list varglist);
Описание (Description)
The printw, wprintw, mvprintw and mvwprintw routines are
analogous to printf [see printf(3)]. In effect, the string that
would be output by printf is output instead as though waddstr
were used on the given window.
The vwprintw and vw_printw routines are analogous to vprintf [see
printf(3)] and perform a wprintw using a variable argument list.
The third argument is a va_list, a pointer to a list of
arguments, as defined in <stdarg.h>.
Возвращаемое значение (Return value)
Routines that return an integer return ERR upon failure and OK
(SVr4 only specifies "an integer value other than ERR") upon
successful completion.
X/Open defines no error conditions. In this implementation, an
error may be returned if it cannot allocate enough memory for the
buffer used to format the results. It will return an error 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.
История (History)
While printw was implemented in 4BSD, it was unused until 4.2BSD
(which used it in games). That early version of curses was
before the ANSI C standard. It did not use <varargs.h>, though
that was available. In 1991 (a couple of years after SVr4 was
generally available, and after the C standard was published),
other developers updated the library, using <stdarg.h> internally
in 4.4BSD curses. Even with this improvement, BSD curses did not
use function prototypes (or even declare functions) in the
<curses.h> header until 1992.
SVr2 documented printw, wprintw tersely as 'printf on stdscr' and
tersely as 'printf on win', respectively.
SVr3 added mvprintw, and mvwprintw, with a three-line summary
saying that they were analogous to printf(3), explaining that the
string which would be output from printf(3) would instead be
output using waddstr on the given window. SVr3 also added
vwprintw, saying that the third parameter is a va_list, defined
in <varargs.h>, and referring the reader to the manual pages for
varargs and vprintf for detailed descriptions.
SVr4 added no new variations of printw, but provided for using
<varargs.h> or <stdarg.h> to define the va_list type.
X/Open Curses added vw_printw to replace vwprintw, stating that
its va_list definition requires <stdarg.h>.
Портативность (Portability)
In this implementation, vw_printw and vwprintw are equivalent, to
support legacy applications. However, the latter (vwprintw) is
obsolete:
• The XSI Curses standard, Issue 4 described these functions.
The function vwprintw is marked TO BE WITHDRAWN, and is to be
replaced by a function vw_printw using the <stdarg.h>
interface.
• The Single Unix Specification, Version 2 states that
vw_printw is preferred to vwprintw since the latter requires
including <varargs.h>, which cannot be used in the same file
as <stdarg.h>. This implementation uses <stdarg.h> for both,
because that header is included in <curses.h>.
• X/Open Curses, Issue 5 (December 2007) marked vwprintw (along
with vwscanw and the termcap interface) as withdrawn.
Смотри также (See also)
curses(3X), curs_addstr(3X), curs_scanw(3X), curs_termcap(3X),
printf(3), vprintf(3).
