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30 * @Id: curs_variables.3x,v 1.15 2020/04/18 14:29:07 tom Exp @
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42 <H1 class="no-header">curs_variables 3x</H1>
44 <STRONG><A HREF="curs_variables.3x.html">curs_variables(3x)</A></STRONG> <STRONG><A HREF="curs_variables.3x.html">curs_variables(3x)</A></STRONG>
49 </PRE><H2><a name="h2-NAME">NAME</a></H2><PRE>
50 <STRONG>COLORS</STRONG>, <STRONG>COLOR_PAIRS</STRONG>, <STRONG>COLS</STRONG>, <STRONG>ESCDELAY</STRONG>, <STRONG>LINES</STRONG>, <STRONG>TABSIZE</STRONG>, <STRONG>curscr</STRONG>, <STRONG>newscr</STRONG>,
51 <STRONG>stdscr</STRONG> - <STRONG>curses</STRONG> global variables
54 </PRE><H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE>
55 <STRONG>#include</STRONG> <STRONG><curses.h></STRONG>
57 <STRONG>int</STRONG> <STRONG>COLOR_PAIRS;</STRONG>
58 <STRONG>int</STRONG> <STRONG>COLORS;</STRONG>
59 <STRONG>int</STRONG> <STRONG>COLS;</STRONG>
60 <STRONG>int</STRONG> <STRONG>ESCDELAY;</STRONG>
61 <STRONG>int</STRONG> <STRONG>LINES;</STRONG>
62 <STRONG>int</STRONG> <STRONG>TABSIZE;</STRONG>
63 <STRONG>WINDOW</STRONG> <STRONG>*</STRONG> <STRONG>curscr;</STRONG>
64 <STRONG>WINDOW</STRONG> <STRONG>*</STRONG> <STRONG>newscr;</STRONG>
65 <STRONG>WINDOW</STRONG> <STRONG>*</STRONG> <STRONG>stdscr;</STRONG>
68 </PRE><H2><a name="h2-DESCRIPTION">DESCRIPTION</a></H2><PRE>
69 This page summarizes variables provided by the <STRONG>curses</STRONG> library. A more
70 complete description is given in the <STRONG><A HREF="ncurses.3x.html">curses(3x)</A></STRONG> manual page.
72 Depending on the configuration, these may be actual variables, or
73 macros (see <STRONG><A HREF="curs_threads.3x.html">curs_threads(3x)</A></STRONG> and <STRONG><A HREF="curs_opaque.3x.html">curs_opaque(3x)</A></STRONG>) which provide read-
74 only access to <EM>curses</EM>'s state. In either case, applications should
75 treat them as read-only to avoid confusing the library.
78 </PRE><H3><a name="h3-COLOR_PAIRS">COLOR_PAIRS</a></H3><PRE>
79 After initializing curses, this variable contains the number of color
80 pairs which the terminal can support. Usually the number of color
81 pairs will be the product <STRONG>COLORS</STRONG>*<STRONG>COLORS</STRONG>, however this is not always
84 <STRONG>o</STRONG> a few terminals use HLS colors, which do not follow this rule
86 <STRONG>o</STRONG> terminals supporting a large number of colors are limited by the
87 number of color pairs that can be represented in a <EM>signed</EM> <EM>short</EM>
91 </PRE><H3><a name="h3-COLORS">COLORS</a></H3><PRE>
92 After initializing curses, this variable contains the number of colors
93 which the terminal can support.
96 </PRE><H3><a name="h3-COLS">COLS</a></H3><PRE>
97 After initializing curses, this variable contains the width of the
98 screen, i.e., the number of columns.
101 </PRE><H3><a name="h3-ESCDELAY">ESCDELAY</a></H3><PRE>
102 This variable holds the number of milliseconds to wait after reading an
103 escape character, to distinguish between an individual escape character
104 entered on the keyboard from escape sequences sent by cursor- and func-
105 tion-keys (see <STRONG><A HREF="ncurses.3x.html">curses(3x)</A></STRONG>).
108 </PRE><H3><a name="h3-LINES">LINES</a></H3><PRE>
109 After initializing curses, this variable contains the height of the
110 screen, i.e., the number of lines.
113 </PRE><H3><a name="h3-TABSIZE">TABSIZE</a></H3><PRE>
114 This variable holds the number of columns used by the <EM>curses</EM> library
115 when converting a tab character to spaces as it adds the tab to a win-
116 dow (see <STRONG><A HREF="curs_addch.3x.html">curs_addch(3x)</A></STRONG>.
119 </PRE><H3><a name="h3-The-Current-Screen">The Current Screen</a></H3><PRE>
120 This implementation of curses uses a special window <STRONG>curscr</STRONG> to record
121 its updates to the terminal screen.
123 This is referred to as the "physical screen" in the <STRONG><A HREF="curs_refresh.3x.html">curs_refresh(3x)</A></STRONG>
124 and <STRONG><A HREF="curs_outopts.3x.html">curs_outopts(3x)</A></STRONG> manual pages.
127 </PRE><H3><a name="h3-The-New-Screen">The New Screen</a></H3><PRE>
128 This implementation of curses uses a special window <STRONG>newscr</STRONG> to hold up-
129 dates to the terminal screen before applying them to <STRONG>curscr</STRONG>.
131 This is referred to as the "virtual screen" in the <STRONG><A HREF="curs_kernel.3x.html">curs_kernel(3x)</A></STRONG>,
132 <STRONG><A HREF="curs_refresh.3x.html">curs_refresh(3x)</A></STRONG> and <STRONG><A HREF="curs_outopts.3x.html">curs_outopts(3x)</A></STRONG> manual pages.
135 </PRE><H3><a name="h3-The-Standard-Screen">The Standard Screen</a></H3><PRE>
136 Upon initializing curses, a default window called <STRONG>stdscr</STRONG>, which is the
137 size of the terminal screen, is created. Many curses functions use
141 </PRE><H2><a name="h2-NOTES">NOTES</a></H2><PRE>
142 The curses library is initialized using either <STRONG><A HREF="curs_initscr.3x.html">initscr(3x)</A></STRONG>, or
143 <STRONG><A HREF="curs_initscr.3x.html">newterm(3x)</A></STRONG>.
145 If <STRONG>curses</STRONG> is configured to use separate curses/terminfo libraries, most
146 of these variables reside in the curses library.
149 </PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
150 <STRONG>TABSIZE</STRONG> is a feature of SVr4 curses which is not documented by X/Open
153 <STRONG>o</STRONG> In SVr4 curses, <STRONG>TABSIZE</STRONG> is initially set from the terminal descrip-
154 tion's <STRONG>init_tabs</STRONG> capability. After that, it can be altered by the
155 applications using SVr4 curses.
157 SVr4 curses uses the current value of <STRONG>TABSIZE</STRONG> to compute the posi-
158 tion of tabstops for updating both the virtual screen with <STRONG>add-</STRONG>
159 <STRONG><A HREF="addch.3x.html">ch(3x)</A></STRONG> as well as the physical screen with <STRONG><A HREF="curs_terminfo.3x.html">mvcur(3x)</A></STRONG>.
161 <STRONG>o</STRONG> This implementation uses the current value of <STRONG>TABSIZE</STRONG> only for up-
162 dating the virtual screen. It uses the terminal description's <STRONG>it</STRONG>
163 (<STRONG>init_tabs</STRONG>) capability for computing hardware tabs (i.e., tab stops
164 on the physical screen).
166 <STRONG>o</STRONG> Other implementations differ. For instance, NetBSD curses allows
167 <STRONG>TABSIZE</STRONG> to be set through an environment variable. This implemen-
170 NetBSD curses does not support hardware tabs; it uses the <STRONG>init_tabs</STRONG>
171 capability and the <STRONG>TABSIZE</STRONG> variable only for updating the virtual
174 <STRONG>ESCDELAY</STRONG> is an extension in AIX curses:
176 <STRONG>o</STRONG> In AIX, the units for <STRONG>ESCDELAY</STRONG> are <EM>fifths</EM> of a millisecond.
178 <STRONG>o</STRONG> The default value for AIX's <STRONG>ESCDELAY</STRONG> is 0.1 seconds.
180 <STRONG>o</STRONG> AIX also enforces a limit of 10,000 seconds for <STRONG>ESCDELAY</STRONG>; this im-
181 plementation currently has no upper limit.
183 This implementation has long used <STRONG>ESCDELAY</STRONG> with units of milliseconds,
184 making it impossible to be completely compatible with AIX. Likewise,
185 most users have either decided to override the value, or rely upon its
189 </PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE>
190 <STRONG><A HREF="ncurses.3x.html">curses(3x)</A></STRONG>, <STRONG><A HREF="curs_opaque.3x.html">curs_opaque(3x)</A></STRONG>, <STRONG><A HREF="curs_terminfo.3x.html">curs_terminfo(3x)</A></STRONG>, <STRONG><A HREF="curs_threads.3x.html">curs_threads(3x)</A></STRONG>,
191 <STRONG><A HREF="term_variables.3x.html">term_variables(3x)</A></STRONG>, <STRONG><A HREF="terminfo.5.html">terminfo(5)</A></STRONG>.
195 <STRONG><A HREF="curs_variables.3x.html">curs_variables(3x)</A></STRONG>
199 <li><a href="#h2-NAME">NAME</a></li>
200 <li><a href="#h2-SYNOPSIS">SYNOPSIS</a></li>
201 <li><a href="#h2-DESCRIPTION">DESCRIPTION</a>
203 <li><a href="#h3-COLOR_PAIRS">COLOR_PAIRS</a></li>
204 <li><a href="#h3-COLORS">COLORS</a></li>
205 <li><a href="#h3-COLS">COLS</a></li>
206 <li><a href="#h3-ESCDELAY">ESCDELAY</a></li>
207 <li><a href="#h3-LINES">LINES</a></li>
208 <li><a href="#h3-TABSIZE">TABSIZE</a></li>
209 <li><a href="#h3-The-Current-Screen">The Current Screen</a></li>
210 <li><a href="#h3-The-New-Screen">The New Screen</a></li>
211 <li><a href="#h3-The-Standard-Screen">The Standard Screen</a></li>
214 <li><a href="#h2-NOTES">NOTES</a></li>
215 <li><a href="#h2-PORTABILITY">PORTABILITY</a></li>
216 <li><a href="#h2-SEE-ALSO">SEE ALSO</a></li>