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43 <H1 class="no-header">curs_inch 3x 2024-05-25 ncurses 6.5 Library calls</H1>
45 <STRONG><A HREF="curs_inch.3x.html">curs_inch(3x)</A></STRONG> Library calls <STRONG><A HREF="curs_inch.3x.html">curs_inch(3x)</A></STRONG>
50 </PRE><H2><a name="h2-NAME">NAME</a></H2><PRE>
51 <STRONG>inch</STRONG>, <STRONG>winch</STRONG>, <STRONG>mvinch</STRONG>, <STRONG>mvwinch</STRONG> - get a <EM>curses</EM> character from a window
54 </PRE><H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE>
55 <STRONG>#include</STRONG> <STRONG><curses.h></STRONG>
57 <STRONG>chtype</STRONG> <STRONG>inch(void);</STRONG>
58 <STRONG>chtype</STRONG> <STRONG>winch(WINDOW</STRONG> <STRONG>*</STRONG> <EM>win</EM><STRONG>);</STRONG>
59 <STRONG>chtype</STRONG> <STRONG>mvinch(int</STRONG> <EM>y</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>x</EM><STRONG>);</STRONG>
60 <STRONG>chtype</STRONG> <STRONG>mvwinch(WINDOW</STRONG> <STRONG>*</STRONG> <EM>win</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>y</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>x</EM><STRONG>);</STRONG>
63 </PRE><H2><a name="h2-DESCRIPTION">DESCRIPTION</a></H2><PRE>
64 <STRONG>winch</STRONG> returns the <EM>curses</EM> character, including its attributes and color
65 pair identifier, at the cursor position in the window <EM>win</EM>. Subsection
66 "Video Attributes" of <STRONG><A HREF="curs_attr.3x.html">attron(3x)</A></STRONG> explains how to extract these data
67 from a <EM>chtype</EM>. <STRONG><A HREF="ncurses.3x.html">ncurses(3x)</A></STRONG> describes the variants of this function.
70 </PRE><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE>
71 These functions return <STRONG>OK</STRONG> on success and <STRONG>ERR</STRONG> on failure.
73 In <EM>ncurses</EM>, <STRONG>winch</STRONG> returns <STRONG>ERR</STRONG> if <EM>win</EM> is <STRONG>NULL</STRONG>.
75 Functions prefixed with "mv" first perform cursor movement and fail if
76 the position (<EM>y</EM>, <EM>x</EM>) is outside the window boundaries.
79 </PRE><H2><a name="h2-NOTES">NOTES</a></H2><PRE>
80 <STRONG>inch</STRONG>, <STRONG>mvinch</STRONG>, and <STRONG>mvwinch</STRONG> may be implemented as macros.
82 These functions do not fail if the window contains cells of <EM>curses</EM>
83 complex characters; that is, if they contain characters with codes
84 wider than eight bits (or greater than 255 as an unsigned decimal
85 integer). They instead extract only the low-order eight bits of the
86 character code from the cell.
89 </PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
90 X/Open Curses, Issue 4 describes these functions. It specifies no
91 error conditions for them.
94 </PRE><H2><a name="h2-HISTORY">HISTORY</a></H2><PRE>
95 The original <EM>curses</EM> in 4BSD (1980) defined <EM>winch</EM> as a macro accessing
96 the <EM>WINDOW</EM> structure member representing character cell data, at that
97 time a <EM>char</EM>, containing only a 7-bit ASCII character code and a
98 "standout" attribute bit, the only one the library supported.
100 SVr2 <EM>curses</EM> (1984) extended this approach, widening the character code
101 to eight bits and permitting several attributes to be combined with it
102 by storing them together in a <EM>chtype</EM>, an alias of <EM>unsigned</EM> <EM>short</EM>.
103 Because a macro was used, its value was not type-checked as a function
104 return value could have been. Goodheart documented SVr3 (1987) <EM>winch</EM>
105 as returning an <EM>int</EM>. SVr3.1's (1987) <EM>chtype</EM> became an alias of
106 <EM>unsigned</EM> <EM>long</EM>, using 16 bits for the character code and widening the
107 type in practical terms to 32 bits, as 64-bit Unix systems were not yet
108 in wide use, and fixed-width integral types would not be standard until
109 ISO C99. SVr3.2 (1988) added a 6-bit color pair identifier alongside
112 X/Open Curses does not specify the sizes of the character code or color
113 pair identifier, nor the quantity of attribute bits, in <EM>chtype</EM>; these
114 are implementation-dependent. <EM>ncurses</EM> uses eight bits for the
115 character code. An application requiring a wider character type, for
116 instance to represent Unicode, should use the wide-character
117 counterparts of these functions.
120 </PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE>
121 <STRONG><A HREF="curs_in_wch.3x.html">curs_in_wch(3x)</A></STRONG> describes comparable functions of the <EM>ncurses</EM> library
122 in its wide-character configuration (<EM>ncursesw</EM>).
124 <STRONG><A HREF="ncurses.3x.html">curses(3x)</A></STRONG>, <STRONG><A HREF="curs_instr.3x.html">curs_instr(3x)</A></STRONG>
128 ncurses 6.5 2024-05-25 <STRONG><A HREF="curs_inch.3x.html">curs_inch(3x)</A></STRONG>
132 <li><a href="#h2-NAME">NAME</a></li>
133 <li><a href="#h2-SYNOPSIS">SYNOPSIS</a></li>
134 <li><a href="#h2-DESCRIPTION">DESCRIPTION</a></li>
135 <li><a href="#h2-RETURN-VALUE">RETURN VALUE</a></li>
136 <li><a href="#h2-NOTES">NOTES</a></li>
137 <li><a href="#h2-PORTABILITY">PORTABILITY</a></li>
138 <li><a href="#h2-HISTORY">HISTORY</a></li>
139 <li><a href="#h2-SEE-ALSO">SEE ALSO</a></li>