inch(3NCURSES) inch(3NCURSES)
NAME
inch, winch, mvinch, mvwinch - get a character and attributes from a
curses window
SYNOPSIS
#include <curses.h>
chtype inch(void);
chtype winch(WINDOW *win);
chtype mvinch(int y, int x);
chtype mvwinch(WINDOW *win, int y, int x);
DESCRIPTION
These routines return the character, of type chtype, at the current po-
sition in the named window. If any attributes are set for that posi-
tion, their values are OR'ed into the value returned. Constants de-
fined in <curses.h> can be used with the & (logical AND) operator to
extract the character or attributes alone.
Attributes
The following bit-masks may be AND-ed with characters returned by
winch.
A_CHARTEXT Bit-mask to extract character
A_ATTRIBUTES Bit-mask to extract attributes
A_COLOR Bit-mask to extract color-pair field information
RETURN VALUE
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.
The winch function does not return an error if the window contains
characters larger than 8-bits (255). Only the low-order 8 bits of the
character are used by winch.
NOTES
Note that all of these routines may be macros.
PORTABILITY
These functions are described in the XSI Curses standard, Issue 4.
Very old systems (before standardization) provide a different function
with the same name:
• The winch function was part of the original BSD curses library,
which stored a 7-bit character combined with the standout attri-
bute.
In BSD curses, winch returned only the character (as an integer)
with the standout attribute removed.
• System V curses added support for several video attributes which
could be combined with characters in the window.
Reflecting this improvement, the function was altered to return the
character combined with all video attributes in a chtype value.
X/Open Curses does not specify the size and layout of attributes, color
and character values in chtype; it is implementation-dependent. This
implementation uses 8 bits for character values. An application using
more bits, e.g., a Unicode value, should use the wide-character equiva-
lents to these functions.
SEE ALSO
ncurses(3NCURSES)
gives an overview of the WINDOW and chtype data types.
attr(3NCURSES)
goes into more detail, pointing out portability problems and con-
straints on the use of chtype for returning window information.
in_wch(3NCURSES)
describes comparable functions for the wide-character (ncursesw)
library.
inch(3NCURSES)
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