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-<H1 class="no-header">ncurses 3x 2023-12-02 ncurses 6.4 Library calls</H1>
+<H1 class="no-header">ncurses 3x 2024-04-20 ncurses 6.4 Library calls</H1>
<PRE>
<STRONG><A HREF="ncurses.3x.html">ncurses(3x)</A></STRONG> Library calls <STRONG><A HREF="ncurses.3x.html">ncurses(3x)</A></STRONG>
</PRE><H2><a name="h2-DESCRIPTION">DESCRIPTION</a></H2><PRE>
- The <STRONG>ncurses</STRONG> library routines give the user a terminal-independent
- method of updating character screens with reasonable optimization.
- This implementation is "new curses" (ncurses) and is the approved
- replacement for 4.4BSD classic curses, which has been discontinued.
- This describes <STRONG>ncurses</STRONG> version 6.4 (patch 20231202).
-
- The <STRONG>ncurses</STRONG> library emulates the curses library of System V Release 4
- Unix ("SVr4"), and XPG4 (X/Open Portability Guide) curses (also known
- as XSI curses). XSI stands for X/Open System Interfaces Extension.
- The <STRONG>ncurses</STRONG> library is freely redistributable in source form.
-
- <EM>ncurses</EM> man pages employ several sections to clarify matters of usage
+ The "new curses" library offers the programmer a terminal-independent
+ means of reading keyboard and mouse input and updating character-cell
+ terminals with output optimized to minimize screen updates. <EM>ncurses</EM>
+ replaces the <EM>curses</EM> libraries from System V Release 4 Unix ("SVr4") and
+ 4.4BSD Unix, the development of which ceased in the 1990s. This
+ document describes <EM>ncurses</EM> version 6.4 (patch 20240420).
+
+ <EM>ncurses</EM> permits control of the terminal screen's contents; abstraction
+ and subdivision thereof with <EM>windows</EM> and <EM>pads</EM>; the reading of terminal
+ input; control of terminal input and output options; environment query
+ routines; color manipulation; the definition and use of <EM>soft</EM> <EM>label</EM>
+ keys; <EM>terminfo</EM> capability access; a <EM>termcap</EM> compatibility interface;
+ and an abstraction of the system's API for manipulating the terminal
+ (such as <STRONG>termios(3)</STRONG>).
+
+ <EM>ncurses</EM> implements the standard interface described by X/Open Curses
+ Issue 7. In many behavioral details not standardized by X/Open,
+ <EM>ncurses</EM> emulates the <EM>curses</EM> library of SVr4 and provides numerous
+ useful extensions.
+
+ <EM>ncurses</EM> man pages employ several sections to clarify matters of usage
and interoperability with other <EM>curses</EM> implementations.
- <STRONG>o</STRONG> "NOTES" describes matters and caveats of which any user of the
- <EM>ncurses</EM> API should be aware, such as limitations on the size of an
- underlying integral type or the availability of a preprocessor
- macro for a function (which prevents its address from being taken).
- This section also describes implementation details that will be
- significant to the programmer but which are not standardized.
+ <STRONG>o</STRONG> "NOTES" describes issues and caveats of which any user of the
+ <EM>ncurses</EM> API should be aware, such as limitations on the size of an
+ underlying integral type or the availability of a preprocessor
+ macro exclusive of a function definition (which prevents its
+ address from being taken). This section also describes
+ implementation details that will be significant to the programmer
+ but which are not standardized.
<STRONG>o</STRONG> "EXTENSIONS" presents <EM>ncurses</EM> innovations beyond the X/Open Curses
standard and/or the SVr4 <EM>curses</EM> implementation. They are termed
state.
<STRONG>o</STRONG> "PORTABILITY" discusses matters (beyond the exercise of extensions)
- that should be considered when writing to a <EM>curses</EM> standard, or to
+ that should be considered when writing to a <EM>curses</EM> standard, or for
multiple implementations.
<STRONG>o</STRONG> "HISTORY" examines points of detail in <EM>ncurses</EM> and other <EM>curses</EM>
where precedent or inertia have frustrated better design (and, in a
few cases, where such inertia has been overcome).
- A program using these routines must be linked with the <STRONG>-lncurses</STRONG>
- option, or (if it has been generated) with the debugging library
- <STRONG>-lncurses_g</STRONG>. (Your system integrator may also have installed these
- libraries under the names <STRONG>-lcurses</STRONG> and <STRONG>-lcurses_g</STRONG>.) The ncurses_g
- library generates trace logs (in a file called "trace" in the current
- directory) that describe curses actions. See also the section on
- <STRONG>ALTERNATE</STRONG> <STRONG>CONFIGURATIONS</STRONG>.
+ A <EM>curses</EM> application must be linked with the library; use the <STRONG>-lncurses</STRONG>
+ option to your compiler or linker. A debugging version of the library
+ may be available; if so, link with it using <STRONG>-lncurses_g</STRONG>. (Your system
+ integrator may have installed these libraries such that you can use the
+ options <STRONG>-lcurses</STRONG> and <STRONG>-lcurses_g</STRONG>, respectively.) The <EM>ncurses</EM><STRONG>_</STRONG><EM>g</EM> library
+ generates trace logs (in a file called <EM>trace</EM> in the current directory)
+ that describe <EM>ncurses</EM> actions. See section "ALTERNATE CONFIGURATIONS"
+ below.
- The <STRONG>ncurses</STRONG> package supports: overall screen, window and pad
- manipulation; output to windows and pads; reading terminal input;
- control over terminal and <STRONG>curses</STRONG> input and output options; environment
- query routines; color manipulation; use of soft label keys; terminfo
- capabilities; and access to low-level terminal-manipulation routines.
+</PRE><H3><a name="h3-Application-Structure">Application Structure</a></H3><PRE>
+ A <EM>curses</EM> application uses information from the system locale;
+ <STRONG>setlocale(3)</STRONG> prepares it for <EM>curses</EM> library calls.
-</PRE><H3><a name="h3-Initialization">Initialization</a></H3><PRE>
- The library uses the locale which the calling program has initialized.
- That is normally done with <STRONG>setlocale(3)</STRONG>:
-
- <STRONG>setlocale(LC_ALL,</STRONG> <STRONG>"");</STRONG>
+ setlocale(LC_ALL, "");
- If the locale is not initialized, the library assumes that characters
- are printable as in ISO-8859-1, to work with certain legacy programs.
- You should initialize the locale and not rely on specific details of
- the library when the locale has not been setup.
+ If the locale is not thus initialized, the library assumes that
+ characters are printable as in ISO 8859-1, to work with certain legacy
+ programs. You should initialize the locale; do not expect consistent
+ behavior from the library when the locale has not been set up.
- The function <STRONG>initscr</STRONG> or <STRONG>newterm</STRONG> must be called to initialize the
- library before any of the other routines that deal with windows and
- screens are used. The routine <STRONG><A HREF="curs_initscr.3x.html">endwin(3x)</A></STRONG> must be called before
- exiting.
+ <STRONG><A HREF="curs_initscr.3x.html">initscr(3x)</A></STRONG> or <STRONG><A HREF="curs_initscr.3x.html">newterm(3x)</A></STRONG> must be called to initialize <EM>curses</EM> before
+ use of any functions that deal with windows and screens.
- To get character-at-a-time input without echoing (most interactive,
- screen oriented programs want this), the following sequence should be
- used:
+ To get character-at-a-time input without echoing--most interactive,
+ screen-oriented programs want this--use the following sequence.
- <STRONG>initscr();</STRONG> <STRONG>cbreak();</STRONG> <STRONG>noecho();</STRONG>
+ initscr(); cbreak(); noecho();
- Most programs would additionally use the sequence:
+ Most applications perform further setup as follows.
- <STRONG>intrflush(stdscr,</STRONG> <STRONG>FALSE);</STRONG>
- <STRONG>keypad(stdscr,</STRONG> <STRONG>TRUE);</STRONG>
+ intrflush(stdscr, FALSE);
+ keypad(stdscr, TRUE);
- Before a <STRONG>curses</STRONG> program is run, the tab stops of the terminal should be
- set and its initialization strings, if defined, must be output. This
- can be done by executing the <STRONG>tput</STRONG> <STRONG>init</STRONG> command after the shell
- environment variable <EM>TERM</EM> has been exported. (The BSD-style <STRONG><A HREF="tset.1.html">tset(1)</A></STRONG>
- utility also performs this function.) See subsection "Tabs and
- Initialization" of <STRONG><A HREF="terminfo.5.html">terminfo(5)</A></STRONG>.
+ A <EM>curses</EM> program then often enters an event loop of some sort. Call
+ <STRONG><A HREF="curs_initscr.3x.html">endwin(3x)</A></STRONG> before exiting.
-</PRE><H3><a name="h3-Datatypes">Datatypes</a></H3><PRE>
- The <STRONG>ncurses</STRONG> library permits manipulation of data structures, called
- <EM>windows</EM>, which can be thought of as two-dimensional arrays of
- characters representing all or part of a CRT screen. A default window
- called <STRONG>stdscr</STRONG>, which is the size of the terminal screen, is supplied.
- Others may be created with <STRONG>newwin</STRONG>.
+</PRE><H3><a name="h3-Overview">Overview</a></H3><PRE>
+ A <EM>curses</EM> library abstracts the terminal screen by representing all or
+ part of it as a <EM>WINDOW</EM> data structure. A <EM>window</EM> is a rectangular grid
+ of character cells, addressed by row and column coordinates (<EM>y</EM>, <EM>x</EM>),
+ with the upper left corner as (0, 0). A window called <STRONG>stdscr</STRONG>, the same
+ size as the terminal screen, is always available. Create others with
+ <STRONG><A HREF="curs_window.3x.html">newwin(3x)</A></STRONG>.
- Note that <STRONG>curses</STRONG> does not handle overlapping windows, that's done by
- the <STRONG><A HREF="panel.3x.html">panel(3x)</A></STRONG> library. This means that you can either use <STRONG>stdscr</STRONG> or
- divide the screen into tiled windows and not using <STRONG>stdscr</STRONG> at all.
- Mixing the two will result in unpredictable, and undesired, effects.
+ A <EM>curses</EM> library does not manage overlapping windows (but see below).
+ You can either use <STRONG>stdscr</STRONG> to manage one screen-filling window, or tile
+ the screen into non-overlapping windows and not use <STRONG>stdscr</STRONG> at all.
+ Mixing the two approaches will result in unpredictable and undesired
+ effects.
- Windows are referred to by variables declared as <STRONG>WINDOW</STRONG> <STRONG>*</STRONG>. These data
- structures are manipulated with routines described here and elsewhere
- in the <STRONG>ncurses</STRONG> manual pages. Among those, the most basic routines are
- <STRONG>move</STRONG> and <STRONG>addch</STRONG>. More general versions of these routines are included
- with names beginning with <STRONG>w</STRONG>, allowing the user to specify a window.
- The routines not beginning with <STRONG>w</STRONG> affect <STRONG>stdscr</STRONG>.
+ Functions permit manipulation of a window and the <EM>cursor</EM> identifying
+ the cell within it at which the next output operation will occur.
+ Among those, the most basic are <STRONG><A HREF="curs_move.3x.html">move(3x)</A></STRONG> and <STRONG><A HREF="curs_addch.3x.html">addch(3x)</A></STRONG>: these place the
+ cursor and write a character to <STRONG>stdscr</STRONG>, respectively.
- After using routines to manipulate a window, <STRONG><A HREF="curs_refresh.3x.html">refresh(3x)</A></STRONG> is called,
- telling <STRONG>curses</STRONG> to make the user's CRT screen look like <STRONG>stdscr</STRONG>. The
- characters in a window are actually of type <STRONG>chtype</STRONG>, (character and
- attribute data) so that other information about the character may also
- be stored with each character.
+ Frequent changes to the terminal screen can cause unpleasant flicker or
+ inefficient use of the communication channel to the device, so the
+ library does not generally update it automatically. Therefore, after
+ using <EM>curses</EM> functions to accumulate a set of desired updates that make
+ sense to present together, call <STRONG><A HREF="curs_refresh.3x.html">refresh(3x)</A></STRONG> to tell the library to make
+ the user's screen look like <STRONG>stdscr</STRONG>. The library <EM>optimizes</EM> its output
+ by computing a minimal number of operations to mutate the screen from
+ its state at the previous refresh to the new one. Effective
+ optimization demands accurate information about the terminal device:
+ the management of such information is the province of the <STRONG><A HREF="curs_terminfo.3x.html">terminfo(3x)</A></STRONG>
+ API, a feature of every standard <EM>curses</EM> implementation.
Special windows called <EM>pads</EM> may also be manipulated. These are windows
- which are not constrained to the size of the screen and whose contents
- need not be completely displayed. See <STRONG><A HREF="curs_pad.3x.html">curs_pad(3x)</A></STRONG> for more
- information.
-
- In addition to drawing characters on the screen, video attributes and
- colors may be supported, causing the characters to show up in such
- modes as underlined, in reverse video, or in color on terminals that
- support such display enhancements. Line drawing characters may be
- specified to be output. On input, <STRONG>curses</STRONG> is also able to translate
- arrow and function keys that transmit escape sequences into single
- values. The video attributes, line drawing characters, and input
- values use names, defined in <STRONG><curses.h></STRONG>, such as <STRONG>A_REVERSE</STRONG>, <STRONG>ACS_HLINE</STRONG>,
- and <STRONG>KEY_LEFT</STRONG>.
-
-
-</PRE><H3><a name="h3-Environment-variables">Environment variables</a></H3><PRE>
- If the environment variables <EM>LINES</EM> and <EM>COLUMNS</EM> are set, or if the
- program is executing in a window environment, line and column
- information in the environment will override information read by
- <EM>terminfo</EM>. This would affect a program running in an AT&T 630 layer,
- for example, where the size of a screen is changeable (see
- <STRONG>ENVIRONMENT</STRONG>).
-
- If the environment variable <EM>TERMINFO</EM> is defined, any program using
- <STRONG>curses</STRONG> checks for a local terminal definition before checking in the
- standard place. For example, if <EM>TERM</EM> is set to <STRONG>att4424</STRONG>, then the
- compiled terminal definition is found in
-
- <STRONG>/usr/share/terminfo/a/att4424</STRONG>.
-
- (The <STRONG>a</STRONG> is copied from the first letter of <STRONG>att4424</STRONG> to avoid creation of
- huge directories.) However, if <EM>TERMINFO</EM> is set to <STRONG>$HOME/myterms</STRONG>,
- <STRONG>curses</STRONG> first checks
-
- <STRONG>$HOME/myterms/a/att4424</STRONG>,
-
- and if that fails, it then checks
-
- <STRONG>/usr/share/terminfo/a/att4424</STRONG>.
-
- This is useful for developing experimental definitions or when write
- permission in <STRONG>/usr/share/terminfo</STRONG> is not available.
-
- The integer variables <STRONG>LINES</STRONG> and <STRONG>COLS</STRONG> are defined in <STRONG><curses.h></STRONG> and will
- be filled in by <STRONG>initscr</STRONG> with the size of the screen. The constants
- <STRONG>TRUE</STRONG> and <STRONG>FALSE</STRONG> have the values <STRONG>1</STRONG> and <STRONG>0</STRONG>, respectively.
-
- The <STRONG>curses</STRONG> routines also define the <STRONG>WINDOW</STRONG> <STRONG>*</STRONG> variable <STRONG>curscr</STRONG> which is
- used for certain low-level operations like clearing and redrawing a
- screen containing garbage. The <STRONG>curscr</STRONG> can be used in only a few
- routines.
-
-
-</PRE><H3><a name="h3-Routine-and-Argument-Names">Routine and Argument Names</a></H3><PRE>
- Many <STRONG>curses</STRONG> routines have two or more versions. The routines prefixed
- with <EM>w</EM> require a window argument. The routines prefixed with <EM>p</EM> require
- a pad argument. Those without a prefix generally use <STRONG>stdscr</STRONG>.
-
- The routines prefixed with <STRONG>mv</STRONG> require a <EM>y</EM> and <EM>x</EM> coordinate to move to
- before performing the appropriate action. The <STRONG>mv</STRONG> routines imply a call
- to <STRONG>move</STRONG> before the call to the other routine. The coordinate <EM>y</EM> always
- refers to the row (of the window), and <EM>x</EM> always refers to the column.
- The upper left-hand corner is always (0,0), not (1,1).
-
- The routines prefixed with <STRONG>mvw</STRONG> take both a window argument and <EM>x</EM> and <EM>y</EM>
- coordinates. The window argument is always specified before the
- coordinates.
-
- In each case, <EM>win</EM> is the window affected, and <EM>pad</EM> is the pad affected;
- <EM>win</EM> and <EM>pad</EM> are always pointers to type <STRONG>WINDOW</STRONG>.
-
- Option setting routines require a Boolean flag <EM>bf</EM> with the value <STRONG>TRUE</STRONG>
- or <STRONG>FALSE</STRONG>; <EM>bf</EM> is always of type <STRONG>bool</STRONG>. Most of the data types used in
- the library routines, such as <STRONG>WINDOW</STRONG>, <STRONG>SCREEN</STRONG>, <STRONG>bool</STRONG>, and <STRONG>chtype</STRONG> are
- defined in <STRONG><curses.h></STRONG>. Types used for the terminfo routines such as
- <STRONG>TERMINAL</STRONG> are defined in <STRONG><term.h></STRONG>.
-
- This manual page describes functions which may appear in any
- configuration of the library. There are two common configurations of
- the library:
-
- <EM>ncurses</EM>
- the "normal" library, which handles 8-bit characters. The
- normal (8-bit) library stores characters combined with
- attributes in <STRONG>chtype</STRONG> data.
-
- Attributes alone (no corresponding character) may be stored in
- <STRONG>chtype</STRONG> or the equivalent <STRONG>attr_t</STRONG> data. In either case, the data
- is stored in something like an integer.
-
- Each cell (row and column) in a <STRONG>WINDOW</STRONG> is stored as a <STRONG>chtype</STRONG>.
-
- <EM>ncursesw</EM>
- the so-called "wide" library, which handles multibyte
- characters (see the section on <STRONG>ALTERNATE</STRONG> <STRONG>CONFIGURATIONS</STRONG>). The
- "wide" library includes all of the calls from the "normal"
- library. It adds about one third more calls using data types
- which store multibyte characters:
-
- <STRONG>cchar_t</STRONG>
- corresponds to <STRONG>chtype</STRONG>. However it is a structure, because
- more data is stored than can fit into an integer. The
- characters are large enough to require a full integer
- value - and there may be more than one character per cell.
- The video attributes and color are stored in separate
- fields of the structure.
-
- Each cell (row and column) in a <STRONG>WINDOW</STRONG> is stored as a
- <STRONG>cchar_t</STRONG>.
-
- The <STRONG><A HREF="curs_getcchar.3x.html">setcchar(3x)</A></STRONG> and <STRONG><A HREF="curs_getcchar.3x.html">getcchar(3x)</A></STRONG> functions store and
- retrieve the data from a <STRONG>cchar_t</STRONG> structure.
+ that are not constrained to the size of the terminal screen and whose
+ contents need not be completely displayed. See <STRONG><A HREF="curs_pad.3x.html">curs_pad(3x)</A></STRONG>.
- <STRONG>wchar_t</STRONG>
- stores a "wide" character. Like <STRONG>chtype</STRONG>, this may be an
- integer.
+ In addition to drawing characters on the screen, rendering attributes
+ and colors may be supported, causing the characters to show up in such
+ modes as underlined, in reverse video, or in color on terminals that
+ support such display enhancements. See <STRONG><A HREF="curs_attr.3x.html">curs_attr(3x)</A></STRONG>.
- <STRONG>wint_t</STRONG>
- stores a <STRONG>wchar_t</STRONG> or <STRONG>WEOF</STRONG> - not the same, though both may
- have the same size.
+ <EM>curses</EM> predefines constants for a small set of forms-drawing graphics
+ corresponding to the DEC Alternate Character Set (ACS), a feature of
+ VT100 and other terminals. See <STRONG><A HREF="curs_addch.3x.html">waddch(3x)</A></STRONG>.
- The "wide" library provides new functions which are analogous
- to functions in the "normal" library. There is a naming
- convention which relates many of the normal/wide variants: a
- "_w" is inserted into the name. For example, <STRONG>waddch</STRONG> becomes
- <STRONG>wadd_wch</STRONG>.
+ <EM>curses</EM> is implemented using the operating system's terminal driver;
+ keystroke events are received not as scan codes but as byte sequences.
+ Graphical keycaps (alphanumeric and punctuation keys, and the space)
+ appear as-is. Everything else, including the tab, enter/return,
+ keypad, arrow, and function keys, appears as a control character or a
+ multibyte <EM>escape</EM> <EM>sequence.</EM> <EM>curses</EM> translates these into unique <EM>key</EM>
+ <EM>codes.</EM> See <STRONG><A HREF="curs_getch.3x.html">getch(3x)</A></STRONG>.
+ <EM>ncurses</EM> provides reimplementations of the SVr4 <STRONG><A HREF="panel.3x.html">panel(3x)</A></STRONG>, <STRONG><A HREF="form.3x.html">form(3x)</A></STRONG>, and
+ <STRONG><A HREF="menu.3x.html">menu(3x)</A></STRONG> libraries to ease construction of user interfaces with <EM>curses</EM>.
-</PRE><H3><a name="h3-Routine-Name-Index">Routine Name Index</a></H3><PRE>
- The following table lists the <STRONG>curses</STRONG> routines provided in the "normal"
- and "wide" libraries and the names of the manual pages on which they
- are described. Routines flagged with "*" are ncurses-specific, not
- described by XPG4 or present in SVr4.
- <STRONG>curses</STRONG> Routine Name Manual Page Name
+</PRE><H3><a name="h3-Initialization">Initialization</a></H3><PRE>
+ The selection of an appropriate value of <EM>TERM</EM> in the process
+ environment is essential to correct <EM>curses</EM> and <EM>terminfo</EM> library
+ operation. A well-configured system selects a correct <EM>TERM</EM> value
+ automatically; <STRONG><A HREF="tset.1.html">tset(1)</A></STRONG> may assist with troubleshooting exotic
+ situations.
+
+ If you change the terminal type, export the <EM>TERM</EM> environment variable
+ in the shell, then run <STRONG><A HREF="tset.1.html">tset(1)</A></STRONG> or the "<STRONG>tput</STRONG> <STRONG>init</STRONG>" command. See
+ subsection "Tabs and Initialization" of <STRONG><A HREF="terminfo.5.html">terminfo(5)</A></STRONG>.
+
+ If the environment variables <EM>LINES</EM> and <EM>COLUMNS</EM> are set, or if the
+ <EM>curses</EM> program is executing in a graphical windowing environment, the
+ information obtained thence overrides that obtained by <EM>terminfo</EM>. An
+ <EM>ncurses</EM> extension supports resizable terminals; see <STRONG><A HREF="wresize.3x.html">wresize(3x)</A></STRONG>.
+
+ If the environment variable <EM>TERMINFO</EM> is defined, a <EM>curses</EM> program
+ checks first for a terminal type description in the location it
+ identifies. <EM>TERMINFO</EM> is useful for developing experimental type
+ descriptions or when write permission to <EM>/usr/share/terminfo</EM> is not
+ available.
+
+ See section "ENVIRONMENT" below.
+
+
+</PRE><H3><a name="h3-Naming-Conventions">Naming Conventions</a></H3><PRE>
+ <EM>curses</EM> offers many functions in variant forms using a regular set of
+ alternatives to the name of an elemental one. Those prefixed with "w"
+ require a <EM>WINDOW</EM> pointer argument; those with a "mv" prefix first
+ perform cursor movement using <STRONG><A HREF="curs_move.3x.html">wmove(3x)</A></STRONG>; a "mvw" prefix indicates both.
+ The "w" function is typically the elemental one; the removal of this
+ prefix usually indicates operation on <STRONG>stdscr</STRONG>.
+
+ Four functions prefixed with "p" require a pad argument.
+
+ In function synopses, <EM>ncurses</EM> man pages apply the following names to
+ parameters.
+
+ <EM>bf</EM> <EM>bool</EM> (<STRONG>TRUE</STRONG> or <STRONG>FALSE</STRONG>)
+ <EM>c</EM> a <EM>char</EM> or <EM>int</EM>
+ <EM>ch</EM> a <EM>chtype</EM>
+ <EM>wc</EM> a <EM>wchar</EM><STRONG>_</STRONG><EM>t</EM> or <EM>wint</EM><STRONG>_</STRONG><EM>t</EM>
+ <EM>wch</EM> a <EM>cchar</EM><STRONG>_</STRONG><EM>t</EM>
+ <EM>win</EM> pointer to a <EM>WINDOW</EM>
+ <EM>pad</EM> pointer to a <EM>WINDOW</EM> that is a pad
+
+
+</PRE><H3><a name="h3-Wide-and-Non-wide-Character-Configurations">Wide and Non-wide Character Configurations</a></H3><PRE>
+ This manual page describes functions that appear in any configuration
+ of the library. There are two common configurations; see section
+ "ALTERNATE CONFIGURATIONS" below.
+
+ <EM>ncurses</EM> is the library in its "non-wide" configuration, handling only
+ eight-bit characters. It stores a character combined with
+ attributes in a <EM>chtype</EM> datum, which is often an alias of <EM>int</EM>.
+
+ Attributes alone (with no corresponding character) can be
+ stored in variables of <EM>chtype</EM> or <EM>attr</EM><STRONG>_</STRONG><EM>t</EM> type. In either
+ case, they are represented as an integral bit mask.
+
+ Each cell of a <EM>WINDOW</EM> is stored as a <EM>chtype</EM>.
+
+ <EM>ncursesw</EM> is the library in its "wide" configuration, which handles
+ character encodings requiring a larger data type than <EM>char</EM> (a
+ byte-sized type) can represent. It adds about one third more
+ calls using additional data types that can store such
+ <EM>multibyte</EM> characters.
+
+ <EM>cchar</EM><STRONG>_</STRONG><EM>t</EM> corresponds to the non-wide configuration's <EM>chtype</EM>.
+ It always a structure type, because it stores more
+ data than fit into a standard scalar type. A
+ character code may not be representable as a <EM>char</EM>,
+ and moreover more than one character may occupy a
+ cell (as with accent marks and other diacritics).
+ Each character is of type <EM>wchar</EM><STRONG>_</STRONG><EM>t</EM>; a complex
+ character contains one spacing character and zero or
+ more non-spacing characters (see below). Attributes
+ and color data are stored in separate fields of the
+ structure, not combined as in <EM>chtype</EM>.
+
+ Each cell of a <EM>WINDOW</EM> is stored as a <EM>cchar</EM><STRONG>_</STRONG><EM>t</EM>.
+
+ <STRONG><A HREF="curs_getcchar.3x.html">setcchar(3x)</A></STRONG> and <STRONG><A HREF="curs_getcchar.3x.html">getcchar(3x)</A></STRONG> store and retrieve <EM>cchar</EM><STRONG>_</STRONG><EM>t</EM>
+ data. The wide library API of <EM>ncurses</EM> depends on two data
+ types standardized by ISO C95.
+
+ <EM>wchar</EM><STRONG>_</STRONG><EM>t</EM> stores a wide character. Like <EM>chtype</EM>, it may be an
+ alias of <EM>int</EM>. Depending on the character encoding,
+ a wide character may be <EM>spacing</EM>, meaning that it
+ occupies a character cell by itself and typically
+ accompanies cursor advancement, or <EM>non-spacing</EM>,
+ meaning that it occupies the same cell as a spacing
+ character, is often regarded as a "modifier" of the
+ base glyph with which it combines, and typically
+ does not advance the cursor.
+
+ <EM>wint</EM><STRONG>_</STRONG><EM>t</EM> can store a <EM>wchar</EM><STRONG>_</STRONG><EM>t</EM> or the constant <STRONG>WEOF</STRONG>,
+ analogously to the <EM>int</EM>-sized character manipulation
+ functions of ISO C and its constant <STRONG>EOF</STRONG>.
+
+ The wide library provides additional functions that
+ complement those in the non-wide library where the size of
+ the underlying character type is significant. A somewhat
+ regular naming convention relates many of the wide variants
+ to their non-wide counterparts; where a non-wide function
+ name contains "ch" or "str", prefix it with "_w" to obtain
+ the wide counterpart. For example, <STRONG>waddch</STRONG> becomes <STRONG>wadd_wch</STRONG>.
+ (Exceptions that add only "w" comprise <STRONG>addwstr</STRONG>, <STRONG>inwstr</STRONG>, and
+ their variants.)
+
+ This convention is inapplicable to some non-wide function
+ names, so other transformations are used for the wide
+ configuration: the window background management function
+ "bkgd" becomes "bkgrnd"; the window border-drawing and
+ -clearing functions are suffixed with "_set"; and character
+ attribute manipulation functions like "attron" become
+ "attr_on".
+
+
+</PRE><H3><a name="h3-Function-Name-Index">Function Name Index</a></H3><PRE>
+ The following table lists the <EM>curses</EM> functions provided in the non-wide
+ and wide APIs and the corresponding man pages that describe them.
+ Those flagged with "*" are <EM>ncurses</EM>-specific, neither described by
+ X/Open Curses nor present in SVr4.
+
+ <STRONG><EM>curses</EM></STRONG> Function Name Man Page
---------------------------------------------
COLOR_PAIR <STRONG><A HREF="curs_color.3x.html">curs_color(3x)</A></STRONG>
- PAIR_NUMBER <STRONG><A HREF="curs_attr.3x.html">curs_attr(3x)</A></STRONG>
+ PAIR_NUMBER <STRONG><A HREF="curs_color.3x.html">curs_color(3x)</A></STRONG>
add_wch <STRONG><A HREF="curs_add_wch.3x.html">curs_add_wch(3x)</A></STRONG>
add_wchnstr <STRONG><A HREF="curs_add_wchstr.3x.html">curs_add_wchstr(3x)</A></STRONG>
add_wchstr <STRONG><A HREF="curs_add_wchstr.3x.html">curs_add_wchstr(3x)</A></STRONG>
addchnstr <STRONG><A HREF="curs_addchstr.3x.html">curs_addchstr(3x)</A></STRONG>
addchstr <STRONG><A HREF="curs_addchstr.3x.html">curs_addchstr(3x)</A></STRONG>
addnstr <STRONG><A HREF="curs_addstr.3x.html">curs_addstr(3x)</A></STRONG>
-
addnwstr <STRONG><A HREF="curs_addwstr.3x.html">curs_addwstr(3x)</A></STRONG>
addstr <STRONG><A HREF="curs_addstr.3x.html">curs_addstr(3x)</A></STRONG>
addwstr <STRONG><A HREF="curs_addwstr.3x.html">curs_addwstr(3x)</A></STRONG>
doupdate <STRONG><A HREF="curs_refresh.3x.html">curs_refresh(3x)</A></STRONG>
dupwin <STRONG><A HREF="curs_window.3x.html">curs_window(3x)</A></STRONG>
echo <STRONG><A HREF="curs_inopts.3x.html">curs_inopts(3x)</A></STRONG>
+
echo_wchar <STRONG><A HREF="curs_add_wch.3x.html">curs_add_wch(3x)</A></STRONG>
echochar <STRONG><A HREF="curs_addch.3x.html">curs_addch(3x)</A></STRONG>
endwin <STRONG><A HREF="curs_initscr.3x.html">curs_initscr(3x)</A></STRONG>
flash <STRONG><A HREF="curs_beep.3x.html">curs_beep(3x)</A></STRONG>
flushinp <STRONG><A HREF="curs_util.3x.html">curs_util(3x)</A></STRONG>
free_pair <STRONG><A HREF="new_pair.3x.html">new_pair(3x)</A></STRONG>*
+ get_escdelay <STRONG><A HREF="curs_threads.3x.html">curs_threads(3x)</A></STRONG>*
get_wch <STRONG><A HREF="curs_get_wch.3x.html">curs_get_wch(3x)</A></STRONG>
-
get_wstr <STRONG><A HREF="curs_get_wstr.3x.html">curs_get_wstr(3x)</A></STRONG>
getattrs <STRONG><A HREF="curs_attr.3x.html">curs_attr(3x)</A></STRONG>
getbegx <STRONG><A HREF="curs_legacy.3x.html">curs_legacy(3x)</A></STRONG>*
init_pair <STRONG><A HREF="curs_color.3x.html">curs_color(3x)</A></STRONG>
initscr <STRONG><A HREF="curs_initscr.3x.html">curs_initscr(3x)</A></STRONG>
innstr <STRONG><A HREF="curs_instr.3x.html">curs_instr(3x)</A></STRONG>
+
innwstr <STRONG><A HREF="curs_inwstr.3x.html">curs_inwstr(3x)</A></STRONG>
ins_nwstr <STRONG><A HREF="curs_ins_wstr.3x.html">curs_ins_wstr(3x)</A></STRONG>
ins_wch <STRONG><A HREF="curs_ins_wch.3x.html">curs_ins_wch(3x)</A></STRONG>
is_idcok <STRONG><A HREF="curs_opaque.3x.html">curs_opaque(3x)</A></STRONG>*
is_idlok <STRONG><A HREF="curs_opaque.3x.html">curs_opaque(3x)</A></STRONG>*
is_immedok <STRONG><A HREF="curs_opaque.3x.html">curs_opaque(3x)</A></STRONG>*
-
is_keypad <STRONG><A HREF="curs_opaque.3x.html">curs_opaque(3x)</A></STRONG>*
is_leaveok <STRONG><A HREF="curs_opaque.3x.html">curs_opaque(3x)</A></STRONG>*
is_linetouched <STRONG><A HREF="curs_touch.3x.html">curs_touch(3x)</A></STRONG>
mvget_wch <STRONG><A HREF="curs_get_wch.3x.html">curs_get_wch(3x)</A></STRONG>
mvget_wstr <STRONG><A HREF="curs_get_wstr.3x.html">curs_get_wstr(3x)</A></STRONG>
mvgetch <STRONG><A HREF="curs_getch.3x.html">curs_getch(3x)</A></STRONG>
+
mvgetn_wstr <STRONG><A HREF="curs_get_wstr.3x.html">curs_get_wstr(3x)</A></STRONG>
mvgetnstr <STRONG><A HREF="curs_getstr.3x.html">curs_getstr(3x)</A></STRONG>
mvgetstr <STRONG><A HREF="curs_getstr.3x.html">curs_getstr(3x)</A></STRONG>
mvins_wstr <STRONG><A HREF="curs_ins_wstr.3x.html">curs_ins_wstr(3x)</A></STRONG>
mvinsch <STRONG><A HREF="curs_insch.3x.html">curs_insch(3x)</A></STRONG>
mvinsnstr <STRONG><A HREF="curs_insstr.3x.html">curs_insstr(3x)</A></STRONG>
-
mvinsstr <STRONG><A HREF="curs_insstr.3x.html">curs_insstr(3x)</A></STRONG>
mvinstr <STRONG><A HREF="curs_instr.3x.html">curs_instr(3x)</A></STRONG>
mvinwstr <STRONG><A HREF="curs_inwstr.3x.html">curs_inwstr(3x)</A></STRONG>
mvwprintw <STRONG><A HREF="curs_printw.3x.html">curs_printw(3x)</A></STRONG>
mvwscanw <STRONG><A HREF="curs_scanw.3x.html">curs_scanw(3x)</A></STRONG>
mvwvline <STRONG><A HREF="curs_border.3x.html">curs_border(3x)</A></STRONG>
+
mvwvline_set <STRONG><A HREF="curs_border_set.3x.html">curs_border_set(3x)</A></STRONG>
napms <STRONG><A HREF="curs_kernel.3x.html">curs_kernel(3x)</A></STRONG>
newpad <STRONG><A HREF="curs_pad.3x.html">curs_pad(3x)</A></STRONG>
overwrite <STRONG><A HREF="curs_overlay.3x.html">curs_overlay(3x)</A></STRONG>
pair_content <STRONG><A HREF="curs_color.3x.html">curs_color(3x)</A></STRONG>
pecho_wchar <STRONG><A HREF="curs_pad.3x.html">curs_pad(3x)</A></STRONG>
-
pechochar <STRONG><A HREF="curs_pad.3x.html">curs_pad(3x)</A></STRONG>
pnoutrefresh <STRONG><A HREF="curs_pad.3x.html">curs_pad(3x)</A></STRONG>
prefresh <STRONG><A HREF="curs_pad.3x.html">curs_pad(3x)</A></STRONG>
scroll <STRONG><A HREF="curs_scroll.3x.html">curs_scroll(3x)</A></STRONG>
scrollok <STRONG><A HREF="curs_outopts.3x.html">curs_outopts(3x)</A></STRONG>
set_curterm <STRONG><A HREF="curs_terminfo.3x.html">curs_terminfo(3x)</A></STRONG>
+ set_escdelay <STRONG><A HREF="curs_threads.3x.html">curs_threads(3x)</A></STRONG>*
+ set_tabsize <STRONG><A HREF="curs_threads.3x.html">curs_threads(3x)</A></STRONG>*
set_term <STRONG><A HREF="curs_initscr.3x.html">curs_initscr(3x)</A></STRONG>
setcchar <STRONG><A HREF="curs_getcchar.3x.html">curs_getcchar(3x)</A></STRONG>
setscrreg <STRONG><A HREF="curs_outopts.3x.html">curs_outopts(3x)</A></STRONG>
slk_init <STRONG><A HREF="curs_slk.3x.html">curs_slk(3x)</A></STRONG>
slk_label <STRONG><A HREF="curs_slk.3x.html">curs_slk(3x)</A></STRONG>
slk_noutrefresh <STRONG><A HREF="curs_slk.3x.html">curs_slk(3x)</A></STRONG>
+
slk_refresh <STRONG><A HREF="curs_slk.3x.html">curs_slk(3x)</A></STRONG>
slk_restore <STRONG><A HREF="curs_slk.3x.html">curs_slk(3x)</A></STRONG>
slk_set <STRONG><A HREF="curs_slk.3x.html">curs_slk(3x)</A></STRONG>
tgetstr <STRONG><A HREF="curs_termcap.3x.html">curs_termcap(3x)</A></STRONG>
tgoto <STRONG><A HREF="curs_termcap.3x.html">curs_termcap(3x)</A></STRONG>
tigetflag <STRONG><A HREF="curs_terminfo.3x.html">curs_terminfo(3x)</A></STRONG>
-
tigetnum <STRONG><A HREF="curs_terminfo.3x.html">curs_terminfo(3x)</A></STRONG>
tigetstr <STRONG><A HREF="curs_terminfo.3x.html">curs_terminfo(3x)</A></STRONG>
timeout <STRONG><A HREF="curs_inopts.3x.html">curs_inopts(3x)</A></STRONG>
use_env <STRONG><A HREF="curs_util.3x.html">curs_util(3x)</A></STRONG>
use_extended_names <STRONG><A HREF="curs_extend.3x.html">curs_extend(3x)</A></STRONG>*
use_legacy_coding <STRONG><A HREF="legacy_coding.3x.html">legacy_coding(3x)</A></STRONG>*
+ use_screen <STRONG><A HREF="curs_threads.3x.html">curs_threads(3x)</A></STRONG>*
use_tioctl <STRONG><A HREF="curs_util.3x.html">curs_util(3x)</A></STRONG>*
+ use_window <STRONG><A HREF="curs_threads.3x.html">curs_threads(3x)</A></STRONG>*
vid_attr <STRONG><A HREF="curs_terminfo.3x.html">curs_terminfo(3x)</A></STRONG>
vid_puts <STRONG><A HREF="curs_terminfo.3x.html">curs_terminfo(3x)</A></STRONG>
vidattr <STRONG><A HREF="curs_terminfo.3x.html">curs_terminfo(3x)</A></STRONG>
waddnwstr <STRONG><A HREF="curs_addwstr.3x.html">curs_addwstr(3x)</A></STRONG>
waddstr <STRONG><A HREF="curs_addstr.3x.html">curs_addstr(3x)</A></STRONG>
waddwstr <STRONG><A HREF="curs_addwstr.3x.html">curs_addwstr(3x)</A></STRONG>
+
wattr_get <STRONG><A HREF="curs_attr.3x.html">curs_attr(3x)</A></STRONG>
wattr_off <STRONG><A HREF="curs_attr.3x.html">curs_attr(3x)</A></STRONG>
wattr_on <STRONG><A HREF="curs_attr.3x.html">curs_attr(3x)</A></STRONG>
wdelch <STRONG><A HREF="curs_delch.3x.html">curs_delch(3x)</A></STRONG>
wdeleteln <STRONG><A HREF="curs_deleteln.3x.html">curs_deleteln(3x)</A></STRONG>
wecho_wchar <STRONG><A HREF="curs_add_wch.3x.html">curs_add_wch(3x)</A></STRONG>
-
wechochar <STRONG><A HREF="curs_addch.3x.html">curs_addch(3x)</A></STRONG>
wenclose <STRONG><A HREF="curs_mouse.3x.html">curs_mouse(3x)</A></STRONG>*
werase <STRONG><A HREF="curs_clear.3x.html">curs_clear(3x)</A></STRONG>
wscanw <STRONG><A HREF="curs_scanw.3x.html">curs_scanw(3x)</A></STRONG>
wscrl <STRONG><A HREF="curs_scroll.3x.html">curs_scroll(3x)</A></STRONG>
wsetscrreg <STRONG><A HREF="curs_outopts.3x.html">curs_outopts(3x)</A></STRONG>
+
wstandend <STRONG><A HREF="curs_attr.3x.html">curs_attr(3x)</A></STRONG>
wstandout <STRONG><A HREF="curs_attr.3x.html">curs_attr(3x)</A></STRONG>
wsyncdown <STRONG><A HREF="curs_window.3x.html">curs_window(3x)</A></STRONG>
wvline <STRONG><A HREF="curs_border.3x.html">curs_border(3x)</A></STRONG>
wvline_set <STRONG><A HREF="curs_border_set.3x.html">curs_border_set(3x)</A></STRONG>
- Depending on the configuration, additional sets of functions may be
- available:
-
- <STRONG><A HREF="curs_memleaks.3x.html">curs_memleaks(3x)</A></STRONG> - curses memory-leak checking
+ <EM>ncurses</EM>'s <EM>screen-pointer</EM> <EM>extension</EM> adds additional functions
+ corresponding to many of the above, each with an "_sp" suffix; see
+ <STRONG><A HREF="curs_sp_funcs.3x.html">curs_sp_funcs(3x)</A></STRONG>.
- <STRONG><A HREF="curs_sp_funcs.3x.html">curs_sp_funcs(3x)</A></STRONG> - curses screen-pointer extension
-
- <STRONG><A HREF="curs_threads.3x.html">curs_threads(3x)</A></STRONG> - curses thread support
-
- <STRONG><A HREF="curs_trace.3x.html">curs_trace(3x)</A></STRONG> - curses debugging routines
+ The availability of some extensions is configurable when <EM>ncurses</EM> is
+ compiled; see sections "ALTERNATE CONFIGURATIONS" and "EXTENSIONS"
+ below.
</PRE><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE>
- Routines that return an integer return <STRONG>ERR</STRONG> upon failure and an integer
- value other than <STRONG>ERR</STRONG> upon successful completion, unless otherwise noted
- in the routine descriptions.
-
- As a general rule, routines check for null pointers passed as
- parameters, and handle this as an error.
-
- All macros return the value of the <STRONG>w</STRONG> version, except <STRONG>setscrreg</STRONG>,
- <STRONG>wsetscrreg</STRONG>, <STRONG>getyx</STRONG>, <STRONG>getbegyx</STRONG>, and <STRONG>getmaxyx</STRONG>. The return values of
- <STRONG>setscrreg</STRONG>, <STRONG>wsetscrreg</STRONG>, <STRONG>getyx</STRONG>, <STRONG>getbegyx</STRONG>, and <STRONG>getmaxyx</STRONG> are undefined
- (i.e., these should not be used as the right-hand side of assignment
- statements).
-
- Functions with a "mv" prefix first perform a cursor movement using
- <STRONG>wmove</STRONG>, and return an error if the position is outside the window, or if
- the window pointer is null. Most "mv"-prefixed functions (except
- variadic functions such as <STRONG>mvprintw</STRONG>) are provided both as macros and
- functions.
-
- Routines that return pointers return <STRONG>NULL</STRONG> on error.
+ Unless otherwise noted, functions that return an integer return <STRONG>OK</STRONG> on
+ success and <STRONG>ERR</STRONG> on failure. Functions that return pointers return <STRONG>NULL</STRONG>
+ on failure. Typically, <EM>ncurses</EM> treats a null pointer passed as a
+ function parameter as a failure. Functions prefixed with "mv" first
+ perform cursor movement and fail if the position (<EM>y</EM>, <EM>x</EM>) is outside the
+ window boundaries.
</PRE><H2><a name="h2-ENVIRONMENT">ENVIRONMENT</a></H2><PRE>
- The following environment symbols are useful for customizing the
- runtime behavior of the <STRONG>ncurses</STRONG> library. The most important ones have
- been already discussed in detail.
+ The following symbols from the process environment customize the
+ runtime behavior of <EM>ncurses</EM> applications. The library may be
+ configured to disregard the variables <EM>TERMINFO</EM>, <EM>TERMINFO</EM><STRONG>_</STRONG><EM>DIRS</EM>,
+ <EM>TERMPATH</EM>, and <EM>HOME</EM>, if the user is the superuser (root), or the
+ application uses <STRONG>setuid(2)</STRONG> or <STRONG>setgid(2)</STRONG>.
-</PRE><H3><a name="h3-CC-command-character"><EM>CC</EM> command-character</a></H3><PRE>
- When set, change occurrences of the command_character (i.e., the <STRONG>cmdch</STRONG>
- capability) of the loaded terminfo entries to the value of this
- variable. Very few terminfo entries provide this feature.
+</PRE><H3><a name="h3-BAUDRATE"><EM>BAUDRATE</EM></a></H3><PRE>
+ The debugging library checks this variable when the application has
+ redirected output to a file. Its integral value is used for the baud
+ rate. If that value is absent or invalid, <EM>ncurses</EM> uses 9600. This
+ feature allows testers to construct repeatable test cases that take
+ into account optimization decisions that depend on baud rate.
- Because this name is also used in development environments to represent
- the C compiler's name, <STRONG>ncurses</STRONG> ignores it if it does not happen to be a
- single character.
+</PRE><H3><a name="h3-CC-_command-character_"><EM>CC</EM> (command character)</a></H3><PRE>
+ When set, the <STRONG>command_character</STRONG> (<STRONG>cmdch</STRONG>) capability value of loaded
+ <EM>terminfo</EM> entries changes to the value of this variable. Very few <EM>term-</EM>
+ <EM>info</EM> entries provide this feature.
-</PRE><H3><a name="h3-BAUDRATE"><EM>BAUDRATE</EM></a></H3><PRE>
- The debugging library checks this environment variable when the
- application has redirected output to a file. The variable's numeric
- value is used for the baudrate. If no value is found, <STRONG>ncurses</STRONG> uses
- 9600. This allows testers to construct repeatable test-cases that take
- into account costs that depend on baudrate.
+ Because this name is also used in development environments to represent
+ the C compiler's name, <EM>ncurses</EM> ignores its value if it is not one
+ character in length.
</PRE><H3><a name="h3-COLUMNS"><EM>COLUMNS</EM></a></H3><PRE>
- Specify the width of the screen in characters. Applications running in
- a windowing environment usually are able to obtain the width of the
- window in which they are executing. If neither the <EM>COLUMNS</EM> value nor
- the terminal's screen size is available, <STRONG>ncurses</STRONG> uses the size which
- may be specified in the terminfo database (i.e., the <STRONG>cols</STRONG> capability).
-
- It is important that your application use a correct size for the
- screen. This is not always possible because your application may be
- running on a host which does not honor NAWS (Negotiations About Window
- Size), or because you are temporarily running as another user.
- However, setting <EM>COLUMNS</EM> and/or <EM>LINES</EM> overrides the library's use of
- the screen size obtained from the operating system.
-
- Either <EM>COLUMNS</EM> or <EM>LINES</EM> symbols may be specified independently. This
- is mainly useful to circumvent legacy misfeatures of terminal
- descriptions, e.g., xterm which commonly specifies a 65 line screen.
- For best results, <STRONG>lines</STRONG> and <STRONG>cols</STRONG> should not be specified in a terminal
- description for terminals which are run as emulations.
-
- Use the <STRONG>use_env</STRONG> function to disable all use of external environment
- (but not including system calls) to determine the screen size. Use the
- <STRONG>use_tioctl</STRONG> function to update <EM>COLUMNS</EM> or <EM>LINES</EM> to match the screen size
- obtained from system calls or the terminal database.
+ This variable specifies the width of the screen in characters.
+ Applications running in a windowing environment usually are able to
+ obtain the width of the window in which they are executing. If <EM>COLUMNS</EM>
+ is not defined and the terminal's screen size is not available from the
+ terminal driver, <EM>ncurses</EM> uses the size specified by the <STRONG>columns</STRONG> (<STRONG>cols</STRONG>)
+ capability of the terminal type's entry in the <EM>terminfo</EM> database, if
+ any.
+
+ It is important that your application use the correct screen size.
+ Automatic detection thereof is not always possible because an
+ application may be running on a host that does not honor NAWS
+ (Negotiations About Window Size) or as a different user ID than the
+ owner of the terminal device file. Setting <EM>COLUMNS</EM> and/or <EM>LINES</EM>
+ overrides the library's use of the screen size obtained from the
+ operating system.
+
+ The <EM>COLUMNS</EM> and <EM>LINES</EM> variables may be specified independently. This
+ property is useful to circumvent misfeatures of legacy terminal type
+ descriptions; <STRONG>xterm(1)</STRONG> descriptions specifying 65 lines were once
+ notorious. For best results, avoid specifying <STRONG>cols</STRONG> and <STRONG>lines</STRONG>
+ capability codes in <EM>terminfo</EM> descriptions of terminal emulators.
+
+ <STRONG><A HREF="curs_util.3x.html">use_env(3x)</A></STRONG> can disable use of the process environment in determining
+ the screen size. <STRONG><A HREF="curs_util.3x.html">use_tioctl(3x)</A></STRONG> can update <EM>COLUMNS</EM> and <EM>LINES</EM> to match
+ the screen size obtained from system calls or the terminal database.
</PRE><H3><a name="h3-ESCDELAY"><EM>ESCDELAY</EM></a></H3><PRE>
- Specifies the total time, in milliseconds, for which ncurses will await
- a character sequence, e.g., a function key. The default value, 1000
- milliseconds, is enough for most uses. However, it is made a variable
- to accommodate unusual applications.
-
- The most common instance where you may wish to change this value is to
- work with slow hosts, e.g., running on a network. If the host cannot
- read characters rapidly enough, it will have the same effect as if the
- terminal did not send characters rapidly enough. The library will
- still see a timeout.
-
- Note that xterm mouse events are built up from character sequences
- received from the xterm. If your application makes heavy use of
- multiple-clicking, you may wish to lengthen this default value because
- the timeout applies to the composed multi-click event as well as the
- individual clicks.
-
- In addition to the environment variable, this implementation provides a
- global variable with the same name. Portable applications should not
- rely upon the presence of <STRONG>ESCDELAY</STRONG> in either form, but setting the
- environment variable rather than the global variable does not create
- problems when compiling an application.
+ For <EM>curses</EM> to distinguish the ESC character resulting from a user's
+ press of the "Escape" key on the input device from one beginning an
+ <EM>escape</EM> <EM>sequence</EM> (as commonly produced by function keys), it waits after
+ receiving the escape character to see if further characters are
+ available on the input stream within a short interval. A global
+ variable <STRONG>ESCDELAY</STRONG> stores this interval in milliseconds. The default
+ value of 1000 (one second) is adequate for most uses. This environment
+ variable overrides it.
+
+ The most common instance where you may wish to change this value is to
+ work with a remote host over a slow communication channel. If the host
+ running a <EM>curses</EM> application does not receive the characters of an
+ escape sequence in a timely manner, the library can interpret them as
+ multiple key stroke events.
+
+ <STRONG>xterm(1)</STRONG> mouse events are a form of escape sequence; therefore, if your
+ application makes heavy use of multiple-clicking, you may wish to
+ lengthen the default value because the delay applies to the composite
+ multi-click event as well as the individual clicks.
+
+ Portable applications should not rely upon the presence of <STRONG>ESCDELAY</STRONG> in
+ either form, but setting the environment variable rather than the
+ global variable does not create problems when compiling an application.
+
+ If <STRONG><A HREF="curs_inopts.3x.html">keypad(3x)</A></STRONG> is disabled for the <EM>curses</EM> window receiving input, a
+ program must disambiguate escape sequences itself.
</PRE><H3><a name="h3-HOME"><EM>HOME</EM></a></H3><PRE>
- Tells <STRONG>ncurses</STRONG> where your home directory is. That is where it may read
- and write auxiliary terminal descriptions:
-
- $HOME/.termcap
- $HOME/.terminfo
+ <EM>ncurses</EM> may read and write auxiliary terminal descriptions in <EM>.termcap</EM>
+ and <EM>.terminfo</EM> files in the user's home directory.
</PRE><H3><a name="h3-LINES"><EM>LINES</EM></a></H3><PRE>
- Like <EM>COLUMNS</EM>, specify the height of the screen in characters. See
- <EM>COLUMNS</EM> for a detailed description.
+ This counterpart to <EM>COLUMNS</EM> specifies the height of the screen in
+ characters. The corresponding <EM>terminfo</EM> capability and code is <STRONG>lines</STRONG>.
+ See the description of the <EM>COLUMNS</EM> variable above.
</PRE><H3><a name="h3-MOUSE_BUTTONS_123"><EM>MOUSE_BUTTONS_123</EM></a></H3><PRE>
- This applies only to the OS/2 EMX port. It specifies the order of
- buttons on the mouse. OS/2 numbers a 3-button mouse inconsistently
- from other platforms:
-
- 1 = left
- 2 = right
- 3 = middle.
-
- This variable lets you customize the mouse. The variable must be three
- numeric digits 1-3 in any order, e.g., 123 or 321. If it is not
- specified, <STRONG>ncurses</STRONG> uses 132.
+ (OS/2 EMX port only) OS/2 numbers a three-button mouse inconsistently
+ with other platforms, such that 1 is the left button, 2 the right, and
+ 3 the middle. This variable customizes the mouse button numbering.
+ Its value must be three digits 1-3 in any order. By default, <EM>ncurses</EM>
+ assumes a numbering of "132".
</PRE><H3><a name="h3-NCURSES_ASSUMED_COLORS"><EM>NCURSES_ASSUMED_COLORS</EM></a></H3><PRE>
- Override the compiled-in assumption that the terminal's default colors
- are white-on-black (see <STRONG><A HREF="default_colors.3x.html">default_colors(3x)</A></STRONG>). You may set the
- foreground and background color values with this environment variable
- by proving a 2-element list: foreground,background. For example, to
- tell ncurses to not assume anything about the colors, set this to
- "-1,-1". To make it green-on-black, set it to "2,0". Any positive
- value from zero to the terminfo <STRONG>max_colors</STRONG> value is allowed.
+ If set, this variable overrides the <EM>ncurses</EM> library's compiled-in
+ assumption that the terminal's default colors are white on black; see
+ <STRONG><A HREF="default_colors.3x.html">default_colors(3x)</A></STRONG>. Set the foreground and background color values
+ with this environment variable by assigning it two integer values
+ separated by a comma, indicating foregound and background color
+ numbers, respectively.
+ For example, to tell <EM>ncurses</EM> not to assume anything about the colors,
+ use a value of "-1,-1". To make the default color scheme green on
+ black, use "2,0". <EM>ncurses</EM> accepts integral values from -1 up to the
+ value of the <EM>terminfo</EM> <STRONG>max_colors</STRONG> (<STRONG>colors</STRONG>) capability.
-</PRE><H3><a name="h3-NCURSES_CONSOLE2"><EM>NCURSES_CONSOLE2</EM></a></H3><PRE>
- This applies only to the MinGW port of ncurses.
- The <STRONG>Console2</STRONG> program's handling of the Microsoft Console API call
- <STRONG>CreateConsoleScreenBuffer</STRONG> is defective. Applications which use this
- will hang. However, it is possible to simulate the action of this call
- by mapping coordinates, explicitly saving and restoring the original
- screen contents. Setting the environment variable <STRONG>NCGDB</STRONG> has the same
- effect.
+</PRE><H3><a name="h3-NCURSES_CONSOLE2"><EM>NCURSES_CONSOLE2</EM></a></H3><PRE>
+ (MinGW port only) The <EM>Console2</EM> program defectively handles the
+ Microsoft Console API call <EM>CreateConsoleScreenBuffer</EM>. Applications
+ that use it will hang. However, it is possible to simulate the action
+ of this call by mapping coordinates, explicitly saving and restoring
+ the original screen contents. Setting the environment variable <EM>NCGDB</EM>
+ has the same effect.
</PRE><H3><a name="h3-NCURSES_GPM_TERMS"><EM>NCURSES_GPM_TERMS</EM></a></H3><PRE>
- This applies only to ncurses configured to use the GPM interface.
-
- If present, the environment variable is a list of one or more terminal
- names against which the <EM>TERM</EM> environment variable is matched. Setting
- it to an empty value disables the GPM interface; using the built-in
- support for xterm, etc.
-
- If the environment variable is absent, ncurses will attempt to open GPM
- if <EM>TERM</EM> contains "linux".
+ (Linux only) When <EM>ncurses</EM> is configured to use the GPM interface, this
+ variable may list one or more terminal names against which the <EM>TERM</EM>
+ variable (see below) is matched. An empty value disables the GPM
+ interface, using <EM>ncurses</EM>'s built-in support for <STRONG>xterm(1)</STRONG> mouse
+ protocols instead. If the variable is absent, <EM>ncurses</EM> attempts to open
+ GPM if <EM>TERM</EM> contains "linux".
</PRE><H3><a name="h3-NCURSES_NO_HARD_TABS"><EM>NCURSES_NO_HARD_TABS</EM></a></H3><PRE>
- <STRONG>Ncurses</STRONG> may use tabs as part of the cursor movement optimization. In
- some cases, your terminal driver may not handle these properly. Set
- this environment variable to disable the feature. You can also adjust
- your <STRONG>stty(1)</STRONG> settings to avoid the problem.
+ <EM>ncurses</EM> may use tab characters in cursor movement optimization. In
+ some cases, your terminal driver may not handle them properly. Set
+ this environment variable to any value to disable the feature. You can
+ also adjust your <STRONG>stty(1)</STRONG> settings to avoid the problem.
</PRE><H3><a name="h3-NCURSES_NO_MAGIC_COOKIE"><EM>NCURSES_NO_MAGIC_COOKIE</EM></a></H3><PRE>
- Some terminals use a magic-cookie feature which requires special
- handling to make highlighting and other video attributes display
- properly. You can suppress the highlighting entirely for these
- terminals by setting this environment variable.
+ Many terminals store video attributes as a property of a character
+ cell, as <EM>curses</EM> does. Historically, some recorded changes in video
+ attributes as data that logically <EM>occupies</EM> character cells on the
+ display, switching attributes on or off, similarly to tags in a markup
+ language; these are termed "magic cookies", and must be subsequently
+ overprinted. If the <EM>terminfo</EM> entry for your terminal type does not
+ adequately describe its handling of magic cookies, set this variable to
+ any value to instruct <EM>ncurses</EM> to disable attributes entirely.
</PRE><H3><a name="h3-NCURSES_NO_PADDING"><EM>NCURSES_NO_PADDING</EM></a></H3><PRE>
- Most of the terminal descriptions in the terminfo database are written
- for real "hardware" terminals. Many people use terminal emulators
- which run in a windowing environment and use curses-based applications.
- Terminal emulators can duplicate all of the important aspects of a
- hardware terminal, but they do not have the same limitations. The
- chief limitation of a hardware terminal from the standpoint of your
- application is the management of dataflow, i.e., timing. Unless a
- hardware terminal is interfaced into a terminal concentrator (which
- does flow control), it (or your application) must manage dataflow,
- preventing overruns. The cheapest solution (no hardware cost) is for
- your program to do this by pausing after operations that the terminal
- does slowly, such as clearing the display.
-
- As a result, many terminal descriptions (including the vt100) have
- delay times embedded. You may wish to use these descriptions, but not
- want to pay the performance penalty.
-
- Set the <EM>NCURSES</EM><STRONG>_</STRONG><EM>NO</EM><STRONG>_</STRONG><EM>PADDING</EM> environment variable to disable all but
- mandatory padding. Mandatory padding is used as a part of special
- control sequences such as <STRONG>flash</STRONG>.
+ Most terminal type descriptions in the <EM>terminfo</EM> database detail
+ hardware devices. Many people use <EM>curses</EM>-based applications in
+ terminal emulator programs that run in a windowing environment. These
+ programs can duplicate all of the important features of a hardware
+ terminal, but often lack their limitations. Chief among these absent
+ drawbacks is the problem of data flow management; that is, limiting the
+ speed of communication to what the hardware could handle. Unless a
+ hardware terminal is interfaced into a terminal concentrator (which
+ does flow control), an application must manage flow control itself to
+ prevent overruns and data loss.
+
+ A solution that comes at no hardware cost is for an application to
+ pause after directing a terminal to execute an operation that it
+ performs slowly, such as clearing the display. Many terminal type
+ descriptions, including that for the VT100, embed delay specifications
+ in capabilities. You may wish to use these temrinal descriptions
+ without paying the performance penalty. Set <EM>NCURSES</EM><STRONG>_</STRONG><EM>NO</EM><STRONG>_</STRONG><EM>PADDING</EM> to any
+ value to disable all but mandatory padding. Mandatory padding is used
+ by such terminal capabilities as <STRONG>flash_screen</STRONG> (<STRONG>flash</STRONG>).
</PRE><H3><a name="h3-NCURSES_NO_SETBUF"><EM>NCURSES_NO_SETBUF</EM></a></H3><PRE>
- This setting is obsolete. Before changes
-
- <STRONG>o</STRONG> started with 5.9 patch 20120825 and
-
- <STRONG>o</STRONG> continued though 5.9 patch 20130126
-
- <STRONG>ncurses</STRONG> enabled buffered output during terminal initialization. This
- was done (as in SVr4 curses) for performance reasons. For testing
- purposes, both of <STRONG>ncurses</STRONG> and certain applications, this feature was
- made optional. Setting the <EM>NCURSES</EM><STRONG>_</STRONG><EM>NO</EM><STRONG>_</STRONG><EM>SETBUF</EM> variable disabled output
- buffering, leaving the output in the original (usually line buffered)
- mode.
-
- In the current implementation, ncurses performs its own buffering and
- does not require this workaround. It does not modify the buffering of
- the standard output.
-
- The reason for the change was to make the behavior for interrupts and
- other signals more robust. One drawback is that certain
- nonconventional programs would mix ordinary stdio calls with ncurses
- calls and (usually) work. This is no longer possible since ncurses is
- not using the buffered standard output but its own output (to the same
- file descriptor). As a special case, the low-level calls such as <STRONG>putp</STRONG>
- still use the standard output. But high-level curses calls do not.
+ (Obsolete) Prior to internal changes developed in <EM>ncurses</EM> 5.9 (patches
+ 20120825 through 20130126), the library used <STRONG>setbuf(3)</STRONG> to enable fully
+ buffered output when initializing the terminal. This was done, as in
+ SVr4 <EM>curses</EM>, to increase performance. For testing purposes, both of
+ <EM>ncurses</EM> and of certain applications, this feature was made optional.
+ Setting this variable disabled output buffering, leaving the output
+ stream in the original (usually line-buffered) mode.
+
+ Nowadays, <EM>ncurses</EM> performs its own buffering and does not require this
+ workaround; it does not modify the buffering of the standard output
+ stream. This approach makes signal handling, as for interrupts, more
+ robust. A drawback is that certain unconventional programs mixed
+ <STRONG>stdio(3)</STRONG> calls with <EM>ncurses</EM> calls and (usually) got the behavior they
+ expected. This is no longer the case; <EM>ncurses</EM> does not write to the
+ standard output file descriptor through a <EM>stdio</EM>-buffered stream.
+
+ As a special case, low-level API calls such as <STRONG><A HREF="curs_terminfo.3x.html">putp(3x)</A></STRONG> still use the
+ standard output stream. High-level <EM>curses</EM> calls such as <STRONG><A HREF="curs_printw.3x.html">printw(3x)</A></STRONG> do
+ not.
</PRE><H3><a name="h3-NCURSES_NO_UTF8_ACS"><EM>NCURSES_NO_UTF8_ACS</EM></a></H3><PRE>
- During initialization, the <STRONG>ncurses</STRONG> library checks for special cases
- where VT100 line-drawing (and the corresponding alternate character set
- capabilities) described in the terminfo are known to be missing.
- Specifically, when running in a UTF-8 locale, the Linux console
- emulator and the GNU screen program ignore these. Ncurses checks the
- <EM>TERM</EM> environment variable for these. For other special cases, you
- should set this environment variable. Doing this tells ncurses to use
- Unicode values which correspond to the VT100 line-drawing glyphs. That
- works for the special cases cited, and is likely to work for terminal
- emulators.
-
- When setting this variable, you should set it to a nonzero value.
- Setting it to zero (or to a nonnumber) disables the special check for
- "linux" and "screen".
-
- As an alternative to the environment variable, ncurses checks for an
- extended terminfo capability <STRONG>U8</STRONG>. This is a numeric capability which
- can be compiled using <STRONG>tic</STRONG> <STRONG>-x</STRONG>. For example
+ At initialization, <EM>ncurses</EM> inspects the <EM>TERM</EM> environment variable for
+ special cases where VT100 forms-drawing characters (and the
+ corresponding alternate character set <EM>terminfo</EM> capabilities) are known
+ to be unsupported by terminal types that otherwise claim VT100
+ compatibility. Specifically, when running in a UTF-8 locale, the Linux
+ virtual console device and the GNU <STRONG>screen(1)</STRONG> program ignore them. Set
+ this variable to a nonzero value to instruct <EM>ncurses</EM> that the
+ terminal's ACS support is broken; the library then outputs Unicode code
+ points that correspond to the forms-drawing characters. Set it to zero
+ (or a non-integer) to disable the special check for terminal type names
+ matching "linux" or "screen", directing <EM>ncurses</EM> to assume that the ACS
+ feature works if the terminal type description advertises it.
+
+ As an alternative to use of this variable, <EM>ncurses</EM> checks for an
+ extended <EM>terminfo</EM> numeric capability <STRONG>U8</STRONG> that can be compiled using "<STRONG>tic</STRONG>
+ <STRONG>-x</STRONG>". Examples follow.
# linux console, if patched to provide working
# VT100 shift-in/shift-out, with corresponding font.
xterm-utf8|xterm relying on UTF-8 line-graphics,
U8#1, use=xterm,
- The name "U8" is chosen to be two characters, to permit it to be used
- by applications that use ncurses' termcap interface.
+ The two-character name "U8" was chosen to permit its use via <EM>ncurses</EM>'s
+ <EM>termcap</EM> interface.
</PRE><H3><a name="h3-NCURSES_TRACE"><EM>NCURSES_TRACE</EM></a></H3><PRE>
- During initialization, the <STRONG>ncurses</STRONG> debugging library checks the
- <EM>NCURSES</EM><STRONG>_</STRONG><EM>TRACE</EM> environment variable. If it is defined, to a numeric
- value, <STRONG>ncurses</STRONG> calls the <STRONG>trace</STRONG> function, using that value as the
- argument.
-
- The argument values, which are defined in <STRONG>curses.h</STRONG>, provide several
- types of information. When running with traces enabled, your
- application will write the file <STRONG>trace</STRONG> to the current directory.
-
- See <STRONG><A HREF="curs_trace.3x.html">curs_trace(3x)</A></STRONG> for more information.
+ At initialization, <EM>ncurses</EM> (in its debugging configuration) checks for
+ this variable's presence. If defined with an integral value, the
+ library calls <STRONG><A HREF="curs_trace.3x.html">curses_trace(3x)</A></STRONG> with that value as the argument.
</PRE><H3><a name="h3-TERM"><EM>TERM</EM></a></H3><PRE>
- Denotes your terminal type. Each terminal type is distinct, though
- many are similar.
-
- <EM>TERM</EM> is commonly set by terminal emulators to help applications find a
- workable terminal description. Some of those choose a popular
- approximation, e.g., "ansi", "vt100", "xterm" rather than an exact fit.
- Not infrequently, your application will have problems with that
- approach, e.g., incorrect function-key definitions.
-
- If you set <EM>TERM</EM> in your environment, it has no effect on the operation
- of the terminal emulator. It only affects the way applications work
- within the terminal. Likewise, as a general rule (<STRONG>xterm(1)</STRONG> being a
- rare exception), terminal emulators which allow you to specify <EM>TERM</EM> as
- a parameter or configuration value do not change their behavior to
- match that setting.
+ The <EM>TERM</EM> variable denotes the terminal type. Each is distinct, though
+ many are similar. It is commonly set by terminal emulators to help
+ applications find a workable terminal description. Some choose a
+ popular approximation such as "ansi", "vt100", or "xterm" rather than
+ an exact fit to their capabilities. Not infrequently, an application
+ will have problems with that approach; for example, a key stroke may
+ not operate correctly, or produce no effect but seeming garbage
+ characters on the screen.
+
+ Setting <EM>TERM</EM> has no effect on hardware operation; it affects the way
+ applications communicate with the terminal. Likewise, as a general
+ rule (<STRONG>xterm(1)</STRONG> being a rare exception), terminal emulators that allow
+ you to specify <EM>TERM</EM> as a parameter or configuration value do not change
+ their behavior to match that setting.
</PRE><H3><a name="h3-TERMCAP"><EM>TERMCAP</EM></a></H3><PRE>
- If the <STRONG>ncurses</STRONG> library has been configured with <EM>termcap</EM> support,
- <STRONG>ncurses</STRONG> will check for a terminal's description in termcap form if it
- is not available in the terminfo database.
-
- The <EM>TERMCAP</EM> environment variable contains either a terminal description
- (with newlines stripped out), or a file name telling where the
- information denoted by the <EM>TERM</EM> environment variable exists. In either
- case, setting it directs <STRONG>ncurses</STRONG> to ignore the usual place for this
- information, e.g., /etc/termcap.
+ If <EM>ncurses</EM> is configured with <EM>termcap</EM> support, it checks for a terminal
+ type description in <EM>termcap</EM> format if one in <EM>terminfo</EM> format is not
+ available. Setting this variable directs <EM>ncurses</EM> to ignore the usual
+ <EM>termcap</EM> database location, <EM>/etc/termcap</EM>; see <EM>TERMPATH</EM> below. <EM>TERMCAP</EM>
+ should contain either a terminal description (with newlines stripped
+ out), or a file name indicating where the information required by the
+ <EM>TERM</EM> environment variable is stored.
</PRE><H3><a name="h3-TERMINFO"><EM>TERMINFO</EM></a></H3><PRE>
- <STRONG>ncurses</STRONG> can be configured to read from multiple terminal databases.
- The <EM>TERMINFO</EM> variable overrides the location for the default terminal
- database. Terminal descriptions (in terminal format) are stored in
- terminal databases:
-
- <STRONG>o</STRONG> Normally these are stored in a directory tree, using subdirectories
- named by the first letter of the terminal names therein.
+ <EM>ncurses</EM> can be configured to read terminal type description databases
+ in various locations using different formats. This variable overrides
+ the default location.
- This is the scheme used in System V, which legacy Unix systems use,
- and the <EM>TERMINFO</EM> variable is used by <EM>curses</EM> applications on those
- systems to override the default location of the terminal database.
+ <STRONG>o</STRONG> Descriptions in <EM>terminfo</EM> format are normally stored in a directory
+ tree using subdirectories named by the common first letters of the
+ terminal types named therein. This is the scheme used in System V.
- <STRONG>o</STRONG> If <STRONG>ncurses</STRONG> is built to use hashed databases, then each entry in
- this list may be the path of a hashed database file, e.g.,
+ <STRONG>o</STRONG> If <EM>ncurses</EM> is configured to use hashed databases, then <EM>TERMINFO</EM> may
+ name its location, such as <EM>/usr/share/terminfo.db</EM>, rather than
+ <EM>/usr/share/terminfo/</EM>.
- /usr/share/terminfo.db
+ The hashed database uses less disk space and is a little faster than
+ the directory tree. However, some applications assume the existence of
+ the directory tree, and read it directly rather than using the <EM>terminfo</EM>
+ API.
- rather than
+ <STRONG>o</STRONG> If <EM>ncurses</EM> is configured with <EM>termcap</EM> support, this variable may
+ contain the location of a <EM>termcap</EM> file.
- /usr/share/terminfo/
+ <STRONG>o</STRONG> If the value of <EM>TERMINFO</EM> begins with "hex:" or "b64:", <EM>ncurses</EM> uses
+ the remainder of the value as a compiled <EM>terminfo</EM> description. You
+ might produce the base64 format using <STRONG><A HREF="infocmp.1m.html">infocmp(1m)</A></STRONG>.
- The hashed database uses less disk-space and is a little faster
- than the directory tree. However, some applications assume the
- existence of the directory tree, reading it directly rather than
- using the terminfo library calls.
+ TERMINFO=$(infocmp -0 -Q2 -q)
+ export TERMINFO
- <STRONG>o</STRONG> If <STRONG>ncurses</STRONG> is built with a support for reading termcap files
- directly, then an entry in this list may be the path of a termcap
- file.
+ The compiled description is used only if it corresponds to the
+ terminal type identified by <EM>TERM</EM>.
- <STRONG>o</STRONG> If the <EM>TERMINFO</EM> variable begins with "hex:" or "b64:", <STRONG>ncurses</STRONG> uses
- the remainder of that variable as a compiled terminal description.
- You might produce the base64 format using <STRONG><A HREF="infocmp.1m.html">infocmp(1m)</A></STRONG>:
+ Setting <EM>TERMINFO</EM> is the simplest, but not the only, way to direct
+ <EM>ncurses</EM> to a terminal database. The search path is as follows.
- TERMINFO="$(infocmp -0 -Q2 -q)"
- export TERMINFO
+ <STRONG>o</STRONG> the last terminal database to which the running <EM>ncurses</EM> application
+ wrote, if any
- The compiled description is used if it corresponds to the terminal
- identified by the <EM>TERM</EM> variable.
+ <STRONG>o</STRONG> the location specified by the <EM>TERMINFO</EM> environment variable
- Setting <EM>TERMINFO</EM> is the simplest, but not the only way to set location
- of the default terminal database. The complete list of database
- locations in order follows:
+ <STRONG>o</STRONG> <EM>$HOME/.terminfo</EM>
- <STRONG>o</STRONG> the last terminal database to which <STRONG>ncurses</STRONG> wrote, if any, is
- searched first
+ <STRONG>o</STRONG> locations listed in the <EM>TERMINFO</EM><STRONG>_</STRONG><EM>DIRS</EM> environment variable
- <STRONG>o</STRONG> the location specified by the <EM>TERMINFO</EM> environment variable
+ <STRONG>o</STRONG> location(s) configured and compiled into <EM>ncurses</EM>
- <STRONG>o</STRONG> $HOME/.terminfo
-
- <STRONG>o</STRONG> locations listed in the <EM>TERMINFO</EM><STRONG>_</STRONG><EM>DIRS</EM> environment variable
-
- <STRONG>o</STRONG> one or more locations whose names are configured and compiled
- into the ncurses library, i.e.,
-
- <STRONG>o</STRONG> /usr/share/terminfo (corresponding to the <EM>TERMINFO</EM><STRONG>_</STRONG><EM>DIRS</EM>
- variable)
-
- <STRONG>o</STRONG> /usr/share/terminfo (corresponding to the <EM>TERMINFO</EM> variable)
+ <STRONG>o</STRONG> <EM>/usr/share/terminfo</EM>
</PRE><H3><a name="h3-TERMINFO_DIRS"><EM>TERMINFO_DIRS</EM></a></H3><PRE>
- Specifies a list of locations to search for terminal descriptions.
- Each location in the list is a terminal database as described in the
- section on the <EM>TERMINFO</EM> variable. The list is separated by colons
- (i.e., ":") on Unix, semicolons on OS/2 EMX.
-
- There is no corresponding feature in System V terminfo; it is an
- extension developed for <STRONG>ncurses</STRONG>.
+ This variable specifies a list of locations, akin to <EM>PATH</EM>, in which
+ <EM>ncurses</EM> searches for the terminal type descriptions described by
+ <EM>TERMINFO</EM> above. The list items are separated by colons on Unix and
+ semicolons on OS/2 EMX. System V <EM>terminfo</EM> lacks a corresponding
+ feature; <EM>TERMINFO</EM><STRONG>_</STRONG><EM>DIRS</EM> is an <EM>ncurses</EM> extension.
</PRE><H3><a name="h3-TERMPATH"><EM>TERMPATH</EM></a></H3><PRE>
- If <EM>TERMCAP</EM> does not hold a file name then <STRONG>ncurses</STRONG> checks the <EM>TERMPATH</EM>
- environment variable. This is a list of filenames separated by spaces
- or colons (i.e., ":") on Unix, semicolons on OS/2 EMX.
-
- If the <EM>TERMPATH</EM> environment variable is not set, <STRONG>ncurses</STRONG> looks in the
- files
-
- /etc/termcap, /usr/share/misc/termcap and $HOME/.termcap,
-
- in that order.
-
- The library may be configured to disregard the following variables when
- the current user is the superuser (root), or if the application uses
- setuid or setgid permissions:
+ If <EM>TERMCAP</EM> does not hold a terminal type description or file name, then
+ <EM>ncurses</EM> checks the contents of <EM>TERMPATH</EM>, a list of locations, akin to
+ <EM>PATH</EM>, in which it searches for <EM>termcap</EM> terminal type descriptions. The
+ list items are separated by colons on Unix and semicolons on OS/2 EMX.
- $TERMINFO, $TERMINFO_DIRS, $TERMPATH, as well as $HOME.
+ If both <EM>TERMCAP</EM> and <EM>TERMPATH</EM> are unset or invalid, <EM>ncurses</EM> searches for
+ the files <EM>/etc/termcap</EM>, <EM>/usr/share/misc/termcap</EM>, and <EM>$HOME/.termcap</EM>, in
+ that order.
</PRE><H2><a name="h2-ALTERNATE-CONFIGURATIONS">ALTERNATE CONFIGURATIONS</a></H2><PRE>
- Several different configurations are possible, depending on the
- configure script options used when building <STRONG>ncurses</STRONG>. There are a few
- main options whose effects are visible to the applications developer
- using <STRONG>ncurses</STRONG>:
+ Many different <EM>ncurses</EM> configurations are possible, determined by the
+ options given to the <EM>configure</EM> script when building the library. Run
+ the script with the <STRONG>--help</STRONG> option to peruse them all. A few are of
+ particular significance to the application developer employing <EM>ncurses</EM>.
- --disable-overwrite
- The standard include for <STRONG>ncurses</STRONG> is as noted in <STRONG>SYNOPSIS</STRONG>:
+ <STRONG>--disable-overwrite</STRONG>
+ The standard include for <EM>ncurses</EM> is as noted in <STRONG>SYNOPSIS</STRONG>:
<STRONG>#include</STRONG> <STRONG><curses.h></STRONG>
- This option is used to avoid filename conflicts when <STRONG>ncurses</STRONG> is
- not the main implementation of curses of the computer. If <STRONG>ncurses</STRONG>
+ This option is used to avoid filename conflicts when <EM>ncurses</EM> is
+ not the main implementation of curses of the computer. If <EM>ncurses</EM>
is installed disabling overwrite, it puts its headers in a
subdirectory, e.g.,
It also omits a symbolic link which would allow you to use
<STRONG>-lcurses</STRONG> to build executables.
- --enable-widec
+ <STRONG>--enable-widec</STRONG>
The configure script renames the library and (if the
<STRONG>--disable-overwrite</STRONG> option is used) puts the header files in a
different subdirectory. All of the library names have a "w"
You must also enable the wide-character features in the header
file when compiling for the wide-character library to use the
extended (wide-character) functions. The symbol which enables
- these features has changed since XSI Curses, Issue 4:
+ these features has changed since X/Open Curses, Issue 4:
<STRONG>o</STRONG> Originally, the wide-character feature required the symbol
<STRONG>_XOPEN_SOURCE_EXTENDED</STRONG> but that was only valid for XPG4
than <STRONG>curses.h</STRONG> may require a specific value for <STRONG>_XOPEN_SOURCE</STRONG>
(or a system-specific symbol).
- The <STRONG>curses.h</STRONG> file which is installed for the wide-character
- library is designed to be compatible with the normal library's
- header. Only the size of the <STRONG>WINDOW</STRONG> structure differs, and very
- few applications require more than a pointer to <STRONG>WINDOW</STRONG>s.
+ The <EM>curses.h</EM> header file installed for the wide-character library
+ is designed to be compatible with the non-wide library's header.
+ Only the size of the <EM>WINDOW</EM> structure differs; few applications
+ require more than pointers to <EM>WINDOW</EM>s.
If the headers are installed allowing overwrite, the wide-
character library's headers should be installed last, to allow
applications to be built using either library from the same set of
headers.
- --with-pthread
+ <STRONG>--with-pthread</STRONG>
The configure script renames the library. All of the library
names have a "t" appended to them (before any "w" added by
<STRONG>--enable-widec</STRONG>).
to set these values. Some applications (very few) may require
changes to work with this convention.
- --with-shared
-
- --with-normal
-
- --with-debug
-
- --with-profile
+ <STRONG>--with-shared</STRONG>
+ <STRONG>--with-normal</STRONG>
+ <STRONG>--with-debug</STRONG>
+ <STRONG>--with-profile</STRONG>
The shared and normal (static) library names differ by their
suffixes, e.g., <STRONG>libncurses.so</STRONG> and <STRONG>libncurses.a</STRONG>. The debug and
profiling libraries add a "_g" and a "_p" to the root names
respectively, e.g., <STRONG>libncurses_g.a</STRONG> and <STRONG>libncurses_p.a</STRONG>.
- --with-termlib
+ <STRONG>--with-termlib</STRONG>
Low-level functions which do not depend upon whether the library
supports wide-characters, are provided in the tinfo library.
Those functions are described in these pages:
- <STRONG>o</STRONG> <STRONG><A HREF="curs_extend.3x.html">curs_extend(3x)</A></STRONG> - miscellaneous curses extensions
+ <STRONG>o</STRONG> <STRONG><A HREF="curs_extend.3x.html">curs_extend(3x)</A></STRONG> - miscellaneous <EM>curses</EM> extensions
- <STRONG>o</STRONG> <STRONG><A HREF="curs_inopts.3x.html">curs_inopts(3x)</A></STRONG> - <STRONG>curses</STRONG> input options
+ <STRONG>o</STRONG> <STRONG><A HREF="curs_inopts.3x.html">curs_inopts(3x)</A></STRONG> - <EM>curses</EM> input options
- <STRONG>o</STRONG> <STRONG><A HREF="curs_kernel.3x.html">curs_kernel(3x)</A></STRONG> - low-level <STRONG>curses</STRONG> routines
+ <STRONG>o</STRONG> <STRONG><A HREF="curs_kernel.3x.html">curs_kernel(3x)</A></STRONG> - low-level <EM>curses</EM> routines
- <STRONG>o</STRONG> <STRONG><A HREF="curs_termattrs.3x.html">curs_termattrs(3x)</A></STRONG> - <STRONG>curses</STRONG> environment query routines
+ <STRONG>o</STRONG> <STRONG><A HREF="curs_termattrs.3x.html">curs_termattrs(3x)</A></STRONG> - <EM>curses</EM> environment query routines
- <STRONG>o</STRONG> <STRONG><A HREF="curs_termcap.3x.html">curs_termcap(3x)</A></STRONG> - <STRONG>curses</STRONG> emulation of termcap
+ <STRONG>o</STRONG> <STRONG><A HREF="curs_termcap.3x.html">curs_termcap(3x)</A></STRONG> - <EM>curses</EM> emulation of <EM>termcap</EM>
- <STRONG>o</STRONG> <STRONG><A HREF="curs_terminfo.3x.html">curs_terminfo(3x)</A></STRONG> - <STRONG>curses</STRONG> interfaces to terminfo database
+ <STRONG>o</STRONG> <STRONG><A HREF="curs_terminfo.3x.html">curs_terminfo(3x)</A></STRONG> - <EM>curses</EM> interface to <EM>terminfo</EM> database
- <STRONG>o</STRONG> <STRONG><A HREF="curs_util.3x.html">curs_util(3x)</A></STRONG> - miscellaneous <STRONG>curses</STRONG> utility routines
+ <STRONG>o</STRONG> <STRONG><A HREF="curs_util.3x.html">curs_util(3x)</A></STRONG> - miscellaneous <EM>curses</EM> utility routines
- --with-trace
+ <STRONG>--with-trace</STRONG>
The <STRONG>trace</STRONG> function normally resides in the debug library, but it
is sometimes useful to configure this in the shared library.
Configure scripts should check for the function's existence rather
</PRE><H2><a name="h2-NOTES">NOTES</a></H2><PRE>
- If standard output from a <STRONG>ncurses</STRONG> program is re-directed to something
- which is not a tty, screen updates will be directed to standard error.
- This was an undocumented feature of AT&T System V Release 3 curses.
+ X/Open Curses permits most functions it specifies to be made available
+ as macros as well. <EM>ncurses</EM> does so
+
+ <STRONG>o</STRONG> for functions that return values via their parameters,
+
+ <STRONG>o</STRONG> to support obsolete features,
- See subsection "Header files" below regarding symbols exposed by
+ <STRONG>o</STRONG> to reuse functions (for example, those that move the cursor before
+ another operation), and
+
+ <STRONG>o</STRONG> a few special cases.
+
+ If the standard output file descriptor of an <EM>ncurses</EM> program is
+ redirected to something that is not a terminal device, the library
+ writes screen updates to the standard error file descriptor. This was
+ an undocumented feature of SVr3 <EM>curses</EM>.
+
+ See subsection "Header Files" below regarding symbols exposed by
inclusion of <EM>curses.h</EM>.
</PRE><H2><a name="h2-EXTENSIONS">EXTENSIONS</a></H2><PRE>
- The <STRONG>ncurses</STRONG> library can be compiled with an option (<STRONG>-DUSE_GETCAP</STRONG>) that
- falls back to the old-style /etc/termcap file if the terminal setup
- code cannot find a terminfo entry corresponding to <EM>TERM</EM>. Use of this
- feature is not recommended, as it essentially includes an entire
- termcap compiler in the <STRONG>ncurses</STRONG> startup code, at significant cost in
- core and startup cycles.
-
- The <STRONG>ncurses</STRONG> library includes facilities for capturing mouse events on
- certain terminals (including xterm). See the <STRONG><A HREF="curs_mouse.3x.html">curs_mouse(3x)</A></STRONG> manual
- page for details.
-
- The <STRONG>ncurses</STRONG> library includes facilities for responding to window
- resizing events, e.g., when running in an xterm. See the
- <STRONG><A HREF="resizeterm.3x.html">resizeterm(3x)</A></STRONG> and <STRONG><A HREF="wresize.3x.html">wresize(3x)</A></STRONG> manual pages for details. In addition,
- the library may be configured with a <STRONG>SIGWINCH</STRONG> handler.
-
- The <STRONG>ncurses</STRONG> library extends the fixed set of function key capabilities
- of terminals by allowing the application designer to define additional
- key sequences at runtime. See the <STRONG><A HREF="define_key.3x.html">define_key(3x)</A></STRONG> <STRONG><A HREF="key_defined.3x.html">key_defined(3x)</A></STRONG>, and
- <STRONG><A HREF="keyok.3x.html">keyok(3x)</A></STRONG> manual pages for details.
-
- The <STRONG>ncurses</STRONG> library can exploit the capabilities of terminals which
- implement the ISO-6429 SGR 39 and SGR 49 controls, which allow an
- application to reset the terminal to its original foreground and
- background colors. From the users' perspective, the application is
- able to draw colored text on a background whose color is set
- independently, providing better control over color contrasts. See the
- <STRONG><A HREF="default_colors.3x.html">default_colors(3x)</A></STRONG> manual page for details.
-
- The <STRONG>ncurses</STRONG> library includes a function for directing application
- output to a printer attached to the terminal device. See the
- <STRONG><A HREF="curs_print.3x.html">curs_print(3x)</A></STRONG> manual page for details.
+ <EM>ncurses</EM> enables an application to capture mouse events on certain
+ terminals, including <STRONG>xterm(1)</STRONG>; see <STRONG><A HREF="curs_mouse.3x.html">curs_mouse(3x)</A></STRONG>.
+ <EM>ncurses</EM> provides a means of responding to window resizing events, as
+ when running in a GUI terminal emulator application such as <EM>xterm</EM>; see
+ <STRONG><A HREF="resizeterm.3x.html">resizeterm(3x)</A></STRONG> and <STRONG><A HREF="wresize.3x.html">wresize(3x)</A></STRONG>.
-</PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
- The <STRONG>ncurses</STRONG> library is intended to be BASE-level conformant with XSI
- Curses. The EXTENDED XSI Curses functionality (including color
- support) is supported.
+ <EM>ncurses</EM> allows an application to query the terminal for the presence of
+ a wide variety of special keys; see <STRONG><A HREF="curs_getch.3x.html">has_key(3x)</A></STRONG>.
- A small number of local differences (that is, individual differences
- between the XSI Curses and <STRONG>ncurses</STRONG> calls) are described in <STRONG>PORTABILITY</STRONG>
- sections of the library man pages.
+ <EM>ncurses</EM> extends the fixed set of function key capabilities specified by
+ X/Open Curses by allowing the application programmer to define
+ additional key events at runtime; see <STRONG><A HREF="define_key.3x.html">define_key(3x)</A></STRONG>, <STRONG><A HREF="key_defined.3x.html">key_defined(3x)</A></STRONG>,
+ <STRONG><A HREF="keybound.3x.html">keybound(3x)</A></STRONG>, and <STRONG><A HREF="keyok.3x.html">keyok(3x)</A></STRONG>.
+ <EM>ncurses</EM> can exploit the capabilities of terminals implementing
+ ISO 6429/ECMA-48 SGR 39 and SGR 49 sequences, which allow an
+ application to reset the terminal to its original foreground and
+ background colors. From a user's perspective, the application is able
+ to draw colored text on a background whose color is set independently,
+ providing better control over color contrasts. See <STRONG><A HREF="default_colors.3x.html">default_colors(3x)</A></STRONG>.
-</PRE><H3><a name="h3-Error-checking">Error checking</a></H3><PRE>
- In many cases, X/Open Curses is vague about error conditions, omitting
- some of the SVr4 documentation.
+ An <EM>ncurses</EM> application can eschew knowledge of <EM>WINDOW</EM> structure
+ internals, instead using accessor functions such as <STRONG><A HREF="curs_opaque.3x.html">is_scrollok(3x)</A></STRONG>.
+
+ <EM>ncurses</EM> enables an application to direct application output to a
+ printer attached to the terminal device; see <STRONG><A HREF="curs_print.3x.html">curs_print(3x)</A></STRONG>.
- Unlike other implementations, this one checks parameters such as
- pointers to WINDOW structures to ensure they are not null. The main
- reason for providing this behavior is to guard against programmer
- error. The standard interface does not provide a way for the library
- to tell an application which of several possible errors were detected.
- Relying on this (or some other) extension will adversely affect the
- portability of curses applications.
+ <EM>ncurses</EM> offers <STRONG><A HREF="curs_slk.3x.html">slk_attr(3x)</A></STRONG> as a counterpart of <STRONG><A HREF="curs_attr.3x.html">attr_get(3x)</A></STRONG> for soft-
+ label key lines, and <STRONG><A HREF="curs_slk.3x.html">extended_slk_color(3x)</A></STRONG> as a form of <STRONG><A HREF="curs_slk.3x.html">slk_color(3x)</A></STRONG>
+ that can gather color information from them when many colors are
+ supported.
+ Some extensions are available only if <EM>ncurses</EM> permits modification of
+ <STRONG><A HREF="unctrl.3x.html">unctrl(3x)</A></STRONG>'s behavior; see <STRONG><A HREF="legacy_coding.3x.html">use_legacy_coding(3x)</A></STRONG>. <EM>ncurses</EM> is compiled
+ to support them; section "ALTERNATE CONFIGURATIONS" describes how.
-</PRE><H3><a name="h3-Extensions-versus-portability">Extensions versus portability</a></H3><PRE>
- Most of the extensions provided by ncurses have not been standardized.
- Some have been incorporated into other implementations, such as
- PDCurses or NetBSD curses. Here are a few to consider:
+ <STRONG>o</STRONG> Rudimentary support for multi-threaded applications may be
+ available; see <STRONG><A HREF="curs_threads.3x.html">curs_threads(3x)</A></STRONG>.
- <STRONG>o</STRONG> The routine <STRONG>has_key</STRONG> is not part of XPG4, nor is it present in SVr4.
- See the <STRONG><A HREF="curs_getch.3x.html">curs_getch(3x)</A></STRONG> manual page for details.
+ <STRONG>o</STRONG> Functions that ease the management of multiple screens can be
+ exposed; see <STRONG><A HREF="curs_sp_funcs.3x.html">curs_sp_funcs(3x)</A></STRONG>.
- <STRONG>o</STRONG> The routine <STRONG>slk_attr</STRONG> is not part of XPG4, nor is it present in
- SVr4. See the <STRONG><A HREF="curs_slk.3x.html">curs_slk(3x)</A></STRONG> manual page for details.
+ <STRONG>o</STRONG> To aid applications to debug their memory usage, <EM>ncurses</EM> optionally
+ offers functions to more aggressively free memory it dynamically
+ allocates itself; see <STRONG><A HREF="curs_memleaks.3x.html">curs_memleaks(3x)</A></STRONG>.
- <STRONG>o</STRONG> The routines <STRONG>getmouse</STRONG>, <STRONG>mousemask</STRONG>, <STRONG>ungetmouse</STRONG>, <STRONG>mouseinterval</STRONG>, and
- <STRONG>wenclose</STRONG> relating to mouse interfacing are not part of XPG4, nor
- are they present in SVr4. See the <STRONG><A HREF="curs_mouse.3x.html">curs_mouse(3x)</A></STRONG> manual page for
- details.
+ <STRONG>o</STRONG> The library facilitates auditing and troubleshooting of its
+ behavior; see <STRONG><A HREF="curs_trace.3x.html">curs_trace(3x)</A></STRONG>.
- <STRONG>o</STRONG> The routine <STRONG>mcprint</STRONG> was not present in any previous curses
- implementation. See the <STRONG><A HREF="curs_print.3x.html">curs_print(3x)</A></STRONG> manual page for details.
+ <STRONG>o</STRONG> The compiler option <STRONG>-DUSE_GETCAP</STRONG> causes the library to fall back to
+ reading <EM>/etc/termcap</EM> if the terminal setup code cannot find a <EM>term-</EM>
+ <EM>info</EM> entry corresponding to <EM>TERM</EM>. Use of this feature is not
+ recommended, as it essentially includes an entire <EM>termcap</EM> compiler
+ in the <EM>ncurses</EM> startup code, at a cost in memory usage and
+ application launch latency.
- <STRONG>o</STRONG> The routine <STRONG>wresize</STRONG> is not part of XPG4, nor is it present in SVr4.
- See the <STRONG><A HREF="wresize.3x.html">wresize(3x)</A></STRONG> manual page for details.
+ <EM>PDCurses</EM> and NetBSD <EM>curses</EM> incorporate some <EM>ncurses</EM> extensions.
+ Individual man pages indicate where this is the case.
- <STRONG>o</STRONG> The WINDOW structure's internal details can be hidden from
- application programs. See <STRONG><A HREF="curs_opaque.3x.html">curs_opaque(3x)</A></STRONG> for the discussion of
- <STRONG>is_scrollok</STRONG>, etc.
- <STRONG>o</STRONG> This implementation can be configured to provide rudimentary
- support for multi-threaded applications. See <STRONG><A HREF="curs_threads.3x.html">curs_threads(3x)</A></STRONG> for
- details.
+</PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
+ X/Open Curses defines two levels of conformance, "base" and "enhanced".
+ The latter includes several additional features, such as wide-character
+ and color support. <EM>ncurses</EM> intends base-level conformance with X/Open
+ Curses, and supports nearly all features of its enhanced level.
+
+ Differences between X/Open Curses and <EM>ncurses</EM> are documented in the
+ "PORTABILITY" sections of applicable man pages.
+
+
+</PRE><H3><a name="h3-Error-Checking">Error Checking</a></H3><PRE>
+ In many cases, X/Open Curses is vague about error conditions, omitting
+ some of the SVr4 documentation.
- <STRONG>o</STRONG> This implementation can also be configured to provide a set of
- functions which improve the ability to manage multiple screens.
- See <STRONG><A HREF="curs_sp_funcs.3x.html">curs_sp_funcs(3x)</A></STRONG> for details.
+ Unlike other implementations, <EM>ncurses</EM> checks pointer parameters, such
+ as those to <EM>WINDOW</EM> structures, to ensure that they are not null. This
+ is done primarily to guard against programmer error. The standard
+ interface does not provide a way for the library to tell an application
+ which of several possible errors occurred. Relying on this (or some
+ other) extension adversely affects the portability of <EM>curses</EM>
+ applications.
-</PRE><H3><a name="h3-Padding-differences">Padding differences</a></H3><PRE>
- In historic curses versions, delays embedded in the capabilities <STRONG>cr</STRONG>,
- <STRONG>ind</STRONG>, <STRONG>cub1</STRONG>, <STRONG>ff</STRONG> and <STRONG>tab</STRONG> activated corresponding delay bits in the Unix
- tty driver. In this implementation, all padding is done by sending NUL
- bytes. This method is slightly more expensive, but narrows the
- interface to the Unix kernel significantly and increases the package's
- portability correspondingly.
+</PRE><H3><a name="h3-Padding-Differences">Padding Differences</a></H3><PRE>
+ In historical <EM>curses</EM> implementations, delays embedded in the <EM>terminfo</EM>
+ capabilities <STRONG>carriage_return</STRONG> (<STRONG>cr</STRONG>), <STRONG>scroll_forward</STRONG> (<STRONG>ind</STRONG>), <STRONG>cursor_left</STRONG>
+ (<STRONG>cub1</STRONG>), <STRONG>form_feed</STRONG> (<STRONG>ff</STRONG>), and <STRONG>tab</STRONG> (<STRONG>ht</STRONG>) activated corresponding delay bits
+ in the Unix terminal driver. <EM>ncurses</EM> performs all padding by sending
+ NUL bytes to the device. This method is slightly more expensive, but
+ narrows the interface to the Unix kernel significantly and
+ correspondingly increases the package's portability.
-</PRE><H3><a name="h3-Header-
files">Header files</a></H3><PRE>
+</PRE><H3><a name="h3-Header-
Files">Header Files</a></H3><PRE>
The header file <EM>curses.h</EM> itself includes the header files <EM>stdio.h</EM> and
<EM>unctrl.h</EM>.
- X/Open Curses has more to say, but does not finish the story:
+ X/Open Curses has more to say,
- The inclusion of <curses.h> may make visible all symbols from the
- headers <stdio.h>, <term.h>, <termios.h>, and <wchar.h>.
+ The inclusion of <EM>curses.h</EM> may make visible all symbols from the
+ headers <EM>stdio.h</EM>, <EM>term.h</EM>, <EM>termios.h</EM>, and <EM>wchar.h</EM>.
- Here is a more complete story:
+ but does not finish the story. A more complete account follows.
- <STRONG>o</STRONG> Starting with BSD curses, all implementations have included
- <stdio.h>.
+ <STRONG>o</STRONG> Starting with 4BSD <EM>curses</EM> (1980) all implementations have provided
+ a <EM>curses.h</EM> file.
- BSD curses included <curses.h> and <unctrl.h> from an internal
- header "curses.ext" ("ext" was a short name for <EM>externs</EM>).
+ BSD <EM>curses</EM> code included <EM>curses.h</EM> and <EM>unctrl.h</EM> from an internal
+ header file <EM>curses.ext</EM>, where "ext" abbreviated "externs".
- BSD curses used <stdio.h> internally (for <STRONG>printw</STRONG> and <STRONG>scanw</STRONG>), but
- nothing in <curses.h> itself relied upon <stdio.h>.
+ The implementations of <EM>printw</EM> and <EM>scanw</EM> used undocumented internal
+ functions of the standard I/O library (<STRONG>_</STRONG><EM>doprnt</EM> and <STRONG>_</STRONG><EM>doscan</EM>), but
+ nothing in <EM>curses.h</EM> itself relied upon <EM>stdio.h</EM>.
- <STRONG>o</STRONG> SVr2 curses added <STRONG><A HREF="curs_initscr.3x.html">newterm(3x)</A></STRONG>, which relies upon <stdio.h>. That
- is, the function prototype uses <STRONG>FILE</STRONG>.
+ <STRONG>o</STRONG> SVr2 <EM>curses</EM> added <EM>newterm</EM>, which relies upon <EM>stdio.h</EM> because its
+ function prototype employs the <EM>FILE</EM> type.
- SVr4 curses added <STRONG>putwin</STRONG> and <STRONG>getwin</STRONG>, which also use <stdio.h>.
+ SVr4 <EM>curses</EM> added <EM>putwin</EM> and <EM>getwin</EM>, which also use <EM>stdio.h</EM>.
- X/Open Curses documents all three of these functions.
+ X/Open Curses specifies all three of these functions.
- SVr4 curses and X/Open Curses do not require the developer to
- include <stdio.h> before including <curses.h>. Both document
- curses showing <curses.h> as the only required header.
+ SVr4 <EM>curses</EM> and X/Open Curses do not require the developer to
+ include <EM>stdio.h</EM> before <EM>curses.h</EM>. Both document use of <EM>curses</EM> as
+ requiring only <EM>curses.h</EM>.
- As a result, standard <curses.h> will always include <stdio.h>.
+ As a result, standard <EM>curses.h</EM> always includes <EM>stdio.h</EM>.
- <STRONG>o</STRONG> X/Open Curses is inconsistent with respect to SVr4 regarding
- <unctrl.h>.
+ <STRONG>o</STRONG> X/Open Curses and SVr4 <EM>curses</EM> are inconsistent with respect to
+ <EM>unctrl.h</EM>.
- As noted in <STRONG><A HREF="curs_util.3x.html">curs_util(3x)</A></STRONG>, ncurses includes <unctrl.h> from
- <curses.h> (like SVr4).
+ As noted in <STRONG><A HREF="curs_util.3x.html">curs_util(3x)</A></STRONG>, <EM>ncurses</EM> includes <EM>unctrl.h</EM> from <EM>curses.h</EM>
+ (as SVr4 does).
- <STRONG>o</STRONG> X/Open's comments about <term.h> and <termios.h> may refer to HP-UX
- and AIX:
+ <STRONG>o</STRONG> X/Open Curses's comments about <EM>term.h</EM> and <EM>termios.h</EM> may refer to
+ HP-UX and AIX.
- HP-UX curses includes <term.h> from <curses.h> to declare <STRONG>setupterm</STRONG>
- in curses.h, but ncurses (and Solaris curses) do not.
+ HP-UX <EM>curses</EM> includes <EM>term.h</EM> from <EM>curses.h</EM> to declare <EM>setupterm</EM> in
+ <EM>curses.h</EM>, but <EM>ncurses</EM> and Solaris <EM>curses</EM> do not.
- AIX curses includes <term.h> and <termios.h>. Again, ncurses (and
- Solaris curses) do not.
+ AIX <EM>curses</EM> includes <EM>term.h</EM> and termios.h<EM>.</EM> Again, <EM>ncurses</EM> and
+ Solaris <EM>curses</EM> do not.
- <STRONG>o</STRONG> X/Open says that <curses.h> <EM>may</EM> include <term.h>, but there is no
- requirement that it do that.
+ <STRONG>o</STRONG> X/Open Curses says that <EM>curses.h</EM> <STRONG>may</STRONG> include <EM>term.h</EM>, but does not
+ require it to do so.
- Some programs use functions declared in both <curses.h> and
- <term.h>, and must include both headers in the same module. Very
- old versions of AIX curses required including <curses.h> before
- including <term.h>.
+ Some programs use functions declared in both <EM>curses.h</EM> and <EM>term.h</EM>,
+ and must include both header files in the same module. Very old
+ versions of AIX <EM>curses</EM> required inclusion of <EM>curses.h</EM> before
+ <EM>term.h</EM>.
- Because ncurses header files include the headers needed to define
- datatypes used in the headers, ncurses header files can be included
- in any order. But for portability, you should include <curses.h>
- before <term.h>.
+ The header files supplied by <EM>ncurses</EM> include the standard library
+ headers required for its declarations, so <EM>ncurses</EM>'s own header
+ files can be included in any order. But for portability, you
+ should include <EM>curses.h</EM> before <EM>term.h</EM>.
- <STRONG>o</STRONG> X/Open Curses says <EM>"may</EM> <EM>make</EM> <EM>visible"</EM> because including a header
- file does not necessarily make all symbols in it visible (there are
- ifdef's to consider).
+ <STRONG>o</STRONG> X/Open Curses says "may make visible" because including a header
+ file does not necessarily make visible all of the symbols in it
+ (consider <STRONG>#ifdef</STRONG> and similar).
- For instance, in ncurses <wchar.h> <EM>may</EM> be included if the proper
- symbol is defined, and if ncurses is configured for wide-character
- support. If the header is included, its symbols may be made
- visible. That depends on the value used for <STRONG>_XOPEN_SOURCE</STRONG> feature
- test macro.
+ For instance, <EM>ncurses</EM>'s <EM>curses.h</EM> <STRONG>may</STRONG> include <EM>wchar.h</EM> if the proper
+ symbol is defined, and if <EM>ncurses</EM> is configured for wide-character
+ support. If <EM>wchar.h</EM> is included, its symbols <STRONG>may</STRONG> be made visible
+ depending on the value of the <STRONG>_XOPEN_SOURCE</STRONG> feature test macro.
- <STRONG>o</STRONG> X/Open Curses documents one required header, in a special case:
- <stdarg.h> before <curses.h> to prototype the <STRONG>vw_printw</STRONG> and
- <STRONG>vw_scanw</STRONG> functions (as well as the obsolete the <STRONG>vwprintw</STRONG> and
- <STRONG>vwscanw</STRONG> functions). Each of those uses a <STRONG>va_list</STRONG> parameter.
+ <STRONG>o</STRONG> X/Open Curses mandates an application's inclusion of one standard C
+ library header in a special case: <EM>stdarg.h</EM> before <EM>curses.h</EM> to
+ prototype the functions <EM>vw</EM><STRONG>_</STRONG><EM>printw</EM> and <EM>vw</EM><STRONG>_</STRONG><EM>scanw</EM> (as well as the
+ obsolete <EM>vwprintw</EM> and <EM>vwscanw</EM>). Each of these takes a variadic
+ argument list, a <EM>va</EM><STRONG>_</STRONG><EM>list</EM> parameter, like that of <STRONG>printf(3)</STRONG>.
- The two obsolete functions were introduced in SVr3. The other
- functions were introduced in X/Open Curses. In between, SVr4
- curses provided for the possibility that an application might
- include either <varargs.h> or <stdarg.h>. Initially, that was done
- by using <STRONG>void*</STRONG> for the <STRONG>va_list</STRONG> parameter. Later, a special type
- (defined in <stdio.h>) was introduced, to allow for compiler type-
- checking. That special type is always available, because <stdio.h>
- is always included by <curses.h>.
+ SVr3 <EM>curses</EM> introduced the two obsolete functions, and X/Open
+ Curses the others. In between, SVr4 <EM>curses</EM> provided for the
+ possibility that an application might include either <EM>varargs.h</EM> or
+ <EM>stdarg.h</EM>. These represented contrasting approaches to handling
+ variadic argument lists. The older interface, <EM>varargs.h</EM>, used a
+ pointer to <EM>char</EM> for variadic functions' <EM>va</EM><STRONG>_</STRONG><EM>list</EM> parameter. Later,
+ the list acquired its own standard data type, <EM>va</EM><STRONG>_</STRONG><EM>list</EM>, defined in
+ <EM>stdarg.h</EM>, empowering the compiler to check the types of a function
+ call's actual parameters against the formal ones declared in its
+ prototype.
- None of the X/Open Curses implementations require an application to
- include <stdarg.h> before <curses.h> because they either have
- allowed for a special type, or (like ncurses) include <stdarg.h>
- directly to provide a portable interface.
+ No conforming implementations of X/Open Curses require an
+ application to include <EM>stdarg.h</EM> before <EM>curses.h</EM> because they either
+ have allowed for a special type, or, like <EM>ncurses</EM>, they include
+ <EM>stdarg.h</EM> themselves to provide a portable interface.
</PRE><H2><a name="h2-AUTHORS">AUTHORS</a></H2><PRE>
-ncurses 6.4 202
3-12-02 <STRONG><A HREF="ncurses.3x.html">ncurses(3x)</A></STRONG>
+ncurses 6.4 202
4-04-20 <STRONG><A HREF="ncurses.3x.html">ncurses(3x)</A></STRONG>
</PRE>
<div class="nav">
<ul>
<li><a href="#h2-SYNOPSIS">SYNOPSIS</a></li>
<li><a href="#h2-DESCRIPTION">DESCRIPTION</a>
<ul>
+<li><a href="#h3-Application-Structure">Application Structure</a></li>
+<li><a href="#h3-Overview">Overview</a></li>
<li><a href="#h3-Initialization">Initialization</a></li>
-<li><a href="#h3-Datatypes">Datatypes</a></li>
-<li><a href="#h3-Environment-variables">Environment variables</a></li>
-<li><a href="#h3-Routine-and-Argument-Names">Routine and Argument Names</a></li>
-<li><a href="#h3-Routine-Name-Index">Routine Name Index</a></li>
+<li><a href="#h3-Naming-Conventions">Naming Conventions</a></li>
+<li><a href="#h3-Wide-and-Non-wide-Character-Configurations">Wide and Non-wide Character Configurations</a></li>
+<li><a href="#h3-Function-Name-Index">Function Name Index</a></li>
</ul>
</li>
<li><a href="#h2-RETURN-VALUE">RETURN VALUE</a></li>
<li><a href="#h2-ENVIRONMENT">ENVIRONMENT</a>
<ul>
-<li><a href="#h3-CC-command-character">CC command-character</a></li>
<li><a href="#h3-BAUDRATE">BAUDRATE</a></li>
+<li><a href="#h3-CC-_command-character_">CC (command character)</a></li>
<li><a href="#h3-COLUMNS">COLUMNS</a></li>
<li><a href="#h3-ESCDELAY">ESCDELAY</a></li>
<li><a href="#h3-HOME">HOME</a></li>
<li><a href="#h2-EXTENSIONS">EXTENSIONS</a></li>
<li><a href="#h2-PORTABILITY">PORTABILITY</a>
<ul>
-<li><a href="#h3-Error-checking">Error checking</a></li>
-<li><a href="#h3-Extensions-versus-portability">Extensions versus portability</a></li>
-<li><a href="#h3-Padding-differences">Padding differences</a></li>
-<li><a href="#h3-Header-files">Header files</a></li>
+<li><a href="#h3-Error-Checking">Error Checking</a></li>
+<li><a href="#h3-Padding-Differences">Padding Differences</a></li>
+<li><a href="#h3-Header-Files">Header Files</a></li>
</ul>
</li>
<li><a href="#h2-AUTHORS">AUTHORS</a></li>
projects / ncurses.git / blobdiff