curs_printw(3x) curs_printw(3x)
printw, wprintw, mvprintw, mvwprintw, vwprintw, vw_printw - print
formatted output in curses windows
#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);
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 win-
dow.
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 de-
fined in <stdarg.h>.
Routines that return an integer return ERR upon failure and OK (SVr4
only specifies "an integer value other than ERR") upon successful com-
pletion.
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.
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 improve-
ment, BSD curses did not use function prototypes (or even declare func-
tions) 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 pa-
rameter 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>.
In this implementation, vw_printw and vwprintw are equivalent, to sup-
port legacy applications. However, the latter (vwprintw) is obsolete:
o 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.
o 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>.
o X/Open Curses, Issue 5 (December 2007) marked vwprintw (along with
vwscanw and the termcap interface) as withdrawn.
curses(3x), curs_addstr(3x), curs_scanw(3x), curs_termcap(3x),
printf(3), vprintf(3).
curs_printw(3x)