The ncurses 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.
-
- The ncurses routines emulate the curses(3x) library of
- System V Release 4 UNIX, and the XPG4 curses standard (XSI
- curses) but the ncurses library is freely redistributable
- in source form. Differences from the SVr4 curses are
- summarized under the EXTENSIONS and BUGS sections below
- and described in detail in the EXTENSIONS and BUGS
- sections of individual man pages.
+ independent method of updating character screens with rea-
+ sonable optimization. This implementation is "new curses"
+ (ncurses) and is the approved replacement for 4.4BSD clas-
+ sic curses, which has been discontinued. This describes
+ ncurses version 6.0 (patch 20170218).
+
+ The ncurses library emulates the curses library of System
+ V Release 4 UNIX, and XPG4 (X/Open Portability Guide)
+ curses (also known as XSI curses). XSI stands for X/Open
+ System Interfaces Extension. The ncurses library is
+ freely redistributable in source form. Differences from
+ the SVr4 curses are summarized under the EXTENSIONS and
+ PORTABILITY sections below and described in detail in the
+ respective EXTENSIONS, PORTABILITY and BUGS sections of
+ individual man pages.
+
+ The ncurses library also provides many useful extensions,
+ i.e., features which cannot be implemented by a simple
+ add-on library but which require access to the internals
+ of the library.
A program using these routines must be linked with the
-lncurses option, or (if it has been generated) with the
debugging library -lncurses_g. (Your system integrator
may also have installed these libraries under the names
-lcurses and -lcurses_g.) The ncurses_g library generates
- trace logs (in a file called 'trace' in the current
- directory) that describe curses actions.
+ trace logs (in a file called 'trace' in the current direc-
+ tory) that describe curses actions. See also the section
+ on ALTERNATECONFIGURATIONS.
+
+ The ncurses package supports: overall screen, window and
+ pad manipulation; output to windows and pads; reading ter-
+ minal input; control over terminal and curses input and
+ output options; environment query routines; color manipu-
+ lation; use of soft label keys; terminfo capabilities; and
+ access to low-level terminal-manipulation routines.
+
+
+
+ The library uses the locale which the calling program has
+ initialized. That is normally done with setlocale:
- The ncurses package supports: overall screen, window and
- pad manipulation; output to windows and pads; reading
- terminal input; control over terminal and curses input and
- output options; environment query routines; color
- manipulation; use of soft label keys; terminfo
- capabilities; and access to low-level terminal-
- manipulation routines.
+ setlocale(LC_ALL,"");
+ If the locale is not initialized, the library assumes that
+ characters are printable as in ISO-8859-1, to work with cer-
+ tain legacy programs. You should initialize the locale and
+ not rely on specific details of the library when the locale
+ has not been setup.
- To initialize the routines, the routine initscr or newterm
- must be called before any of the other routines that deal
- with windows and screens are used. The routine endwin
- must be called before exiting. To get character-at-a-time
- input without echoing (most interactive, screen oriented
- programs want this), the following sequence should be
- used:
+ The function initscr or newterm must be called to initial-
+ ize the library before any of the other routines that deal
+ with windows and screens are used. The routine endwin(3x)
+ must be called before exiting.
- initscr();cbreak();noecho();
+ To get character-at-a-time input without echoing (most
+ interactive, screen oriented programs want this), the fol-
+ lowing sequence should be used:
- Most programs would additionally use the sequence:
+ initscr();cbreak();noecho();
+ Most programs would additionally use the sequence:
nonl();intrflush(stdscr,FALSE);keypad(stdscr,TRUE);
-
- Before a curses 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 tputinit command after the shell environment variable
- TERM has been exported. tset(1) is usually responsible
- for doing this. [See terminfo(5) for further details.]
-
- The ncurses library permits manipulation of data
- structures, called windows, which can be thought of as
- two-dimensional arrays of characters representing all or
- part of a CRT screen. A default window called stdscr,
- which is the size of the terminal screen, is supplied.
- Others may be created with newwin.
+ Before a curses 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 tputinit com-
+ mand after the shell environment variable TERM has been
+ exported. tset(1) is usually responsible for doing this.
+ [See terminfo(5) for further details.]
+
+
+
+ The ncurses library permits manipulation of data struc-
+ tures, called windows, which can be thought of as two-
+ dimensional arrays of characters representing all or part
+ of a CRT screen. A default window called stdscr, which is
+ the size of the terminal screen, is supplied. Others may
+ be created with newwin.
Note that curses does not handle overlapping windows,
- that's done by the panel(3x) library. This means that you
- can either use stdscr or divide the screen into tiled
- windows and not using stdscr at all. Mixing the two will
+ that's done by the panel(3x) library. This means that you
+ can either use stdscr or divide the screen into tiled win-
+ dows and not using stdscr at all. Mixing the two will
result in unpredictable, and undesired, effects.
Windows are referred to by variables declared as WINDOW*.
These data structures are manipulated with routines
described here and elsewhere in the ncurses manual pages.
- Among which the most basic routines are move and addch.
+ Among those, the most basic routines are move and addch.
More general versions of these routines are included with
names beginning with w, allowing the user to specify a
- window. The routines not beginning with w affect stdscr.)
+ window. The routines not beginning with w affect stdscr.
- After using routines to manipulate a window, refresh is
- called, telling curses to make the user's CRT screen look
- like stdscr. The characters in a window are actually of
- type chtype, (character and attribute data) so that other
- information about the character may also be stored with
- each character.
+ After using routines to manipulate a window, refresh(3x)
+ is called, telling curses to make the user's CRT screen
+ look like stdscr. The characters in a window are actually
+ of type chtype, (character and attribute data) so that
+ other information about the character may also be stored
+ with each character.
- Special windows called pads may also be manipulated.
+ Special windows called pads 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 curs_pad(3x) 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, curses 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
+ the screen and whose contents need not be completely dis-
+ played. See curs_pad(3x) for more information.
+
+ In addition to drawing characters on the screen, video
+ attributes and colors may be supported, causing the char-
+ acters 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, curses 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
<curses.h>, such as A_REVERSE, ACS_HLINE, and KEY_LEFT.
+
+
If the environment variables LINES and COLUMNS are set, or
- if the program is executing in a window environment, line
- and column information in the environment will override
- information read by terminfo. This would effect a program
- running in an AT&T 630 layer, for example, where the size
+ if the program is executing in a window environment, line
+ and column information in the environment will override
+ information read by terminfo. This would affect a program
+ running in an AT&T 630 layer, for example, where the size
of a screen is changeable (see ENVIRONMENT).
- If the environment variable TERMINFO is defined, any
- program using curses checks for a local terminal
- definition before checking in the standard place. For
- example, if TERM is set to att4424, then the compiled
- terminal definition is found in
-
- /usr/share/terminfo/a/att4424.
+ If the environment variable TERMINFO is defined, any pro-
+ gram using curses checks for a local terminal definition
+ before checking in the standard place. For example, if
+ TERM is set to att4424, then the compiled terminal defini-
+ tion is found in
- (The a is copied from the first letter of att4424 to avoid
- creation of huge directories.) However, if TERMINFO is
- set to $HOME/myterms, curses first checks
+ /usr/share/terminfo/a/att4424.
+ (The a is copied from the first letter of att4424 to avoid
+ creation of huge directories.) However, if TERMINFO is set
+ to $HOME/myterms, curses first checks
$HOME/myterms/a/att4424,
+ and if that fails, it then checks
- and if that fails, it then checks
-
- /usr/share/terminfo/a/att4424.
-
- This is useful for developing experimental definitions or
- when write permission in /usr/share/terminfo is not
- available.
+ /usr/share/terminfo/a/att4424.
+ This is useful for developing experimental definitions or when
+ write permission in /usr/share/terminfo is not available.
The integer variables LINES and COLS are defined in
<curses.h> and will be filled in by initscr with the size
- of the screen. The constants TRUE and FALSE have the
- values 1 and 0, respectively.
+ of the screen. The constants TRUE and FALSE have the val-
+ ues 1 and 0, respectively.
The curses routines also define the WINDOW* variable
curscr which is used for certain low-level operations like
@@ -191,11 +211,11 @@
curscr can be used in only a few routines.
- RoutineandArgumentNames
- Many curses routines have two or more versions. The
- routines prefixed with w require a window argument. The
- routines prefixed with p require a pad argument. Those
- without a prefix generally use stdscr.
+
+ Many curses routines have two or more versions. The rou-
+ tines prefixed with w require a window argument. The rou-
+ tines prefixed with p require a pad argument. Those with-
+ out a prefix generally use stdscr.
The routines prefixed with mv require a y and x coordinate
to move to before performing the appropriate action. The
@@ -209,27 +229,81 @@
specified before the coordinates.
In each case, win is the window affected, and pad is the
- pad affected; win and pad are always pointers to type
- WINDOW.
+ pad affected; win and pad are always pointers to type WIN-
+ DOW.
Option setting routines require a Boolean flag bf with the
- value TRUE or FALSE; bf is always of type bool. The
- variables ch and attrs below are always of type chtype.
- The types WINDOW, SCREEN, bool, and chtype are defined in
- <curses.h>. The type TERMINAL is defined in <term.h>.
- All other arguments are integers.
-
-
- RoutineNameIndex
+ value TRUE or FALSE; bf is always of type bool. Most of
+ the data types used in the library routines, such as WIN-
+ DOW, SCREEN, bool, and chtype are defined in <curses.h>.
+ Types used for the terminfo routines such as TERMINAL are
+ defined in <term.h>.
+
+ This manual page describes functions which may appear in
+ any configuration of the library. There are two common
+ configurations of the library:
+
+ ncurses
+ the "normal" library, which handles 8-bit charac-
+ ters. The normal (8-bit) library stores charac-
+ ters combined with attributes in chtype data.
+
+ Attributes alone (no corresponding character) may
+ be stored in chtype or the equivalent attr_t data.
+ In either case, the data is stored in something
+ like an integer.
+
+ Each cell (row and column) in a WINDOW is stored
+ as a chtype.
+
+ ncursesw
+ the so-called "wide" library, which handles multi-
+ byte characters (see the section on ALTERNATECON-
+ FIGURATIONS). 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:
+
+ cchar_t
+ corresponds to chtype. 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 WINDOW is
+ stored as a cchar_t.
+
+ wchar_t
+ stores a "wide" character. Like chtype, this
+ may be an integer.
+
+ wint_t
+ stores a wchar_t or WEOF - not the same,
+ though both may have the same size.
+
+ 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, waddch
+ becomes wadd_wch.
+
+
+
- Routines that return an integer return ERR upon failure
- and an integer value other than ERR upon successful
- completion, unless otherwise noted in the routine
- descriptions.
+
+ Routines that return an integer return ERR upon failure
+ and an integer value other than ERR upon successful com-
+ pletion, unless otherwise noted in the routine descrip-
+ tions.
+
+ 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 w version, except
- setscrreg, wsetscrreg, getyx, getbegyx, getmaxyx. The
+ setscrreg, wsetscrreg, getyx, getbegyx, and getmaxyx. The
return values of setscrreg, wsetscrreg, getyx, getbegyx,
- and getmaxyx are undefined (i.e., these should not be used
+ and getmaxyx are undefined (i.e., these should not be used
as the right-hand side of assignment statements).
Routines that return pointers return NULL on error.
-
-
ENVIRONMENT
- The following environment symbols are useful for
- customizing the runtime behavior of the ncurses library.
- The most important ones have been already discussed in
- detail.
-
- BAUDRATE
- The debugging library checks this environment symbol
- when the application has redirected output to a file.
- The symbol's numeric value is used for the baudrate.
- If no value is found ncurses uses 9600. This allows
- testers to construct repeatable test-cases that take
- into account costs that depend on baudrate.
-
- CC When set, change occurrences of the command_character
- (i.e., the cmdch capability) of the loaded terminfo
- entries to the value of this symbol. Very few
- terminfo entries provide this feature.
-
- COLUMNS
- 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 $COLUMNS
- value nor the terminal's screen size is available,
- ncurses uses the size which may be specified in the
- terminfo database (i.e., the cols capability).
-
- It is important that your application use a correct
- size for the screen. However, 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.
-
- Either COLUMNS or LINES 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, lines and cols should not be specified
- in a terminal description for terminals which are run
- as emulations.
-
- Use the use_env function to disable this feature.
-
- ESCDELAY
- 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.
-
- HOME Tells ncurses where your home directory is. That is
- where it may read and write auxiliary terminal
- descriptions:
-
- $HOME/.termcap
- $HOME/.terminfo
-
- LINES
- Like COLUMNS, specify the height of the screen in
- characters. See COLUMNS for a detailed description.
-
- MOUSE_BUTTONS_123
- 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 symbol lets you customize the mouse. The symbol
- must be three numeric digits 1-3 in any order, e.g.,
- 123 or 321. If it is not specified, ncurses uses
- 132.
-
- NCURSES_ASSUMED_COLORS
- Override the compiled-in assumption that the
- terminal's default colors are white-on-black (see
- assume_default_colors(3x)). 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
- max_colors value is allowed.
-
- NCURSES_NO_PADDING
- 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 NCURSES_NO_PADDING symbol to disable all but
- mandatory padding. Mandatory padding is used as a
- part of special control sequences such as flash.
-
- NCURSES_NO_SETBUF
- Normally ncurses enables buffered output during
- terminal initialization. This is done (as in SVr4
- curses) for performance reasons. For testing
- purposes, both of ncurses and certain applications,
- this feature is made optional. Setting the
- NCURSES_NO_SETBUF variable disables output buffering,
- leaving the output in the original (usually line
- buffered) mode.
-
- NCURSES_TRACE
- During initialization, the ncurses debugging library
- checks the NCURSES_TRACE symbol. If it is defined,
- to a numeric value, ncurses calls the trace function,
- using that value as the argument.
-
- The argument values, which are defined in curses.h,
- provide several types of information. When running
- with traces enabled, your application will write the
- file trace to the current directory.
-
- TERM Denotes your terminal type. Each terminal type is
- distinct, though many are similar.
-
- TERMCAP
- If the ncurses library has been configured with
- termcap support, ncurses will check for a terminal's
- description in termcap form if it is not available in
- the terminfo database.
-
- The TERMCAP symbol contains either a terminal
- description (with newlines stripped out), or a file
- name telling where the information denoted by the
- TERM symbol exists. In either case, setting it
- directs ncurses to ignore the usual place for this
- information, e.g., /etc/termcap.
-
- TERMINFO
- Overrides the directory in which ncurses searches for
- your terminal description. This is the simplest, but
- not the only way to change the list of directories.
- The complete list of directories in order follows:
-
- - the last directory to which ncurses wrote, if any,
- is searched first.
-
- - the directory specified by the TERMINFO symbol
-
- - $HOME/.terminfo
-
- - directories listed in the TERMINFO_DIRS symbol
-
- - one or more directories whose names are configured
- and compiled into the ncurses library, e.g.,
- /usr/share/terminfo
-
- TERMINFO_DIRS
- Specifies a list of directories to search for
- terminal descriptions. The list is separated by
- colons (i.e., ":") on Unix, semicolons on OS/2 EMX.
- All of the terminal descriptions are in terminfo
- form, which makes a subdirectory named for the first
- letter of the terminal names therein.
-
- TERMPATH
- If TERMCAP does not hold a file name then ncurses
- checks the TERMPATH symbol. This is a list of
- filenames separated by spaces or colons (i.e., ":")
- on Unix, semicolons on OS/2 EMX. If the TERMPATH
- symbol is not set, ncurses 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:
- $TERMINFO, $TERMINFO_DIRS, $TERMPATH, as well as $HOME.
-
+
+ The following environment symbols are useful for customiz-
+ ing the runtime behavior of the ncurses library. The most
+ important ones have been already discussed in detail.
+
+ CC
+ When set, change occurrences of the command_character
+ (i.e., the cmdch capability) of the loaded terminfo
+ entries to the value of this variable. Very few terminfo
+ entries provide this feature.
+
+ Because this name is also used in development environments
+ to represent the C compiler's name, ncurses ignores it if
+ it does not happen to be a single character.
+
+
+
+ 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, ncurses uses 9600. This allows testers to
+ construct repeatable test-cases that take into account
+ costs that depend on baudrate.
+
+
+
+ Specify the width of the screen in characters. Applica-
+ tions running in a windowing environment usually are able
+ to obtain the width of the window in which they are exe-
+ cuting. If neither the COLUMNS value nor the terminal's
+ screen size is available, ncurses uses the size which may
+ be specified in the terminfo database (i.e., the cols
+ 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
+ COLUMNS and/or LINES overrides the library's use of the
+ screen size obtained from the operating system.
+
+ Either COLUMNS or LINES symbols may be specified indepen-
+ dently. This is mainly useful to circumvent legacy mis-
+ features of terminal descriptions, e.g., xterm which com-
+ monly specifies a 65 line screen. For best results, lines
+ and cols should not be specified in a terminal description
+ for terminals which are run as emulations.
+
+ Use the use_env function to disable all use of external
+ environment (but not including system calls) to determine
+ the screen size. Use the use_tioctl function to update
+ COLUMNS or LINES to match the screen size obtained from
+ system calls or the terminal database.
+
+
+
+ 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 net-
+ work. 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 implementa-
+ tion provides a global variable with the same name. Por-
+ table applications should not rely upon the presence of
+ ESCDELAY in either form, but setting the environment vari-
+ able rather than the global variable does not create prob-
+ lems when compiling an application.
+
+
+
+ Tells ncurses where your home directory is. That is where
+ it may read and write auxiliary terminal descriptions:
+
+ $HOME/.termcap
+ $HOME/.terminfo
+
+
+
+ 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, ncurses uses 132.
+
+
+
+ Override the compiled-in assumption that the terminal's
+ default colors are white-on-black (see default_col-
+ ors(3x)). You may set the foreground and background color
+ values with this environment variable by proving a 2-ele-
+ ment 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 max_colors
+ value is allowed.
+
+
+
+ This applies only to the MinGW port of ncurses.
+
+ The Console2 program's handling of the Microsoft Console
+ API call CreateConsoleScreenBuffer is defective. Applica-
+ tions which use this will hang. However, it is possible
+ to simulate the action of this call by mapping coordi-
+ nates, explicitly saving and restoring the original screen
+ contents. Setting the environment variable NCGDB has the
+ same effect.
+
+
+
+ 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 TERM environment
+ variable is matched. Setting it to an empty value dis-
+ ables the GPM interface; using the built-in support for
+ xterm, etc.
+
+ If the environment variable is absent, ncurses will
+ attempt to open GPM if TERM contains "linux".
+
+
+
+ Ncurses may use tabs as part of the cursor movement opti-
+ mization. In some cases, your terminal driver may not
+ handle these properly. Set this environment variable to
+ disable the feature. You can also adjust your stty set-
+ tings to avoid the problem. NCURSES_NO_MAGIC_COOKIE Some
+ terminals use a magic-cookie feature which requires spe-
+ cial handling to make highlighting and other video
+ attributes display properly. You can suppress the high-
+ lighting entirely for these terminals by setting this
+ environment variable.
+
+
+
+ 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 environ-
+ ment and use curses-based applications. Terminal emula-
+ tors can duplicate all of the important aspects of a hard-
+ ware 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 NCURSES_NO_PADDING environment variable to disable
+ all but mandatory padding. Mandatory padding is used as a
+ part of special control sequences such as flash.
+
+
+
+ This setting is obsolete. Before changes
+
+ o started with 5.9 patch 20120825 and
+
+ o continued though 5.9 patch 20130126
+
+ ncurses enabled buffered output during terminal initial-
+ ization. This was done (as in SVr4 curses) for perfor-
+ mance reasons. For testing purposes, both of ncurses and
+ certain applications, this feature was made optional.
+ Setting the NCURSES_NO_SETBUF 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 putp still use the standard output. But high-
+ level curses calls do not.
+
+
+
+ During initialization, the ncurses library checks for spe-
+ cial cases where VT100 line-drawing (and the corresponding
+ alternate character set capabilities) described in the
+ terminfo are known to be missing. Specifically, when run-
+ ning in a UTF-8 locale, the Linux console emulator and the
+ GNU screen program ignore these. Ncurses checks the TERM
+ 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 U8. This is a
+ numeric capability which can be compiled using tic-x.
+ For example
+
+ # linux console, if patched to provide working
+ # VT100 shift-in/shift-out, with corresponding font.
+ linux-vt100|linux console with VT100 line-graphics,
+ U8#0, use=linux,
+
+ # uxterm with vt100Graphics resource set to false
+ 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.
+
+
+
+ During initialization, the ncurses debugging library
+ checks the NCURSES_TRACE environment variable. If it is
+ defined, to a numeric value, ncurses calls the trace func-
+ tion, using that value as the argument.
+
+ The argument values, which are defined in curses.h, pro-
+ vide several types of information. When running with
+ traces enabled, your application will write the file trace
+ to the current directory.
+
+ See curs_trace(3x) for more information.
+
+
+
+ Denotes your terminal type. Each terminal type is dis-
+ tinct, though many are similar.
+
+ TERM is commonly set by terminal emulators to help appli-
+ cations find a workable terminal description. Some of
+ those choose a popular approximation, e.g., "ansi",
+ "vt100", "xterm" rather than an exact fit. Not infre-
+ quently, your application will have problems with that
+ approach, e.g., incorrect function-key definitions.
+
+ If you set TERM 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 (xterm being a rare exception), terminal
+ emulators which allow you to specify TERM as a parameter
+ or configuration value do not change their behavior to
+ match that setting.
-
-
FILES
- /usr/share/tabset
- directory containing initialization files for the
- terminal capability database /usr/share/terminfo
- terminal capability database
+
+ If the ncurses library has been configured with termcap
+ support, ncurses will check for a terminal's description
+ in termcap form if it is not available in the terminfo
+ database.
+
+ The TERMCAP environment variable contains either a termi-
+ nal description (with newlines stripped out), or a file
+ name telling where the information denoted by the TERM
+ environment variable exists. In either case, setting it
+ directs ncurses to ignore the usual place for this infor-
+ mation, e.g., /etc/termcap.
-
-
SEE ALSO
- terminfo(5) and related pages whose names begin "curs_"
- for detailed routine descriptions.
+
+ ncurses can be configured to read from multiple terminal
+ databases. The TERMINFO variable overrides the location
+ for the default terminal database. Terminal descriptions
+ (in terminal format) are stored in terminal databases:
-
-
EXTENSIONS
- The ncurses library can be compiled with an option
- (-DUSE_GETCAP) that falls back to the old-style
- /etc/termcap file if the terminal setup code cannot find a
- terminfo entry corresponding to TERM. Use of this feature
- is not recommended, as it essentially includes an entire
- termcap compiler in the ncurses startup code, at
- significant cost in core and startup cycles.
-
- The ncurses library includes facilities for capturing
- mouse events on certain terminals (including xterm). See
- the curs_mouse(3x) manual page for details.
+ o Normally these are stored in a directory tree, using
+ subdirectories named by the first letter of the termi-
+ nal names therein.
- The ncurses library includes facilities for responding to
- window resizing events, e.g., when running in an xterm.
- See the resizeterm(3x) and wresize(3x) manual pages for
- details. In addition, the library may be configured with
- a SIGWINCH handler.
-
- The ncurses 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 define_key(3x) and keyok(3x) manual pages for
- details.
-
- The ncurses 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 default_colors(3x) manual page for
- details.
+ This is the scheme used in System V, which legacy Unix
+ systems use, and the TERMINFO variable is used by
+ curses applications on those systems to override the
+ default location of the terminal database.
- The ncurses library includes a function for directing
- application output to a printer attached to the terminal
- device. See the curs_print(3x) manual page for details.
+ o If ncurses is built to use hashed databases, then each
+ entry in this list may be the path of a hashed data-
+ base file, e.g.,
+ /usr/share/terminfo.db
-
-
PORTABILITY
- The ncurses library is intended to be BASE-level
- conformant with the XSI Curses standard. Certain portions
- of the EXTENDED XSI Curses functionality (including color
- support) are supported. The following EXTENDED XSI Curses
- calls in support of wide (multibyte) characters are not
- yet implemented: pecho_wchar, slk_wset.
-
- A small number of local differences (that is, individual
- differences between the XSI Curses and ncurses calls) are
- described in PORTABILITY sections of the library man
- pages.
+ rather than
- The routine has_key is not part of XPG4, nor is it present
- in SVr4. See the curs_getch(3x) manual page for details.
+ /usr/share/terminfo/
- The routine slk_attr is not part of XPG4, nor is it
- present in SVr4. See the curs_slk(3x) manual page for
- details.
+ The hashed database uses less disk-space and is a lit-
+ tle faster than the directory tree. However, some
+ applications assume the existence of the directory
+ tree, reading it directly rather than using the ter-
+ minfo library calls.
- The routines getmouse, mousemask, ungetmouse,
- mouseinterval, and wenclose relating to mouse interfacing
- are not part of XPG4, nor are they present in SVr4. See
- the curs_mouse(3x) manual page for details.
+ o If ncurses 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 routine mcprint was not present in any previous curses
- implementation. See the curs_print(3x) manual page for
- details.
+ o If the TERMINFO variable begins with "hex:" or "b64:",
+ ncurses uses the remainder of that variable as a com-
+ piled terminal description. You might produce the
+ base64 format using infocmp(1m):
- The routine wresize is not part of XPG4, nor is it present
- in SVr4. See the wresize(3x) manual page for details.
+ TERMINFO="$(infocmp -0 -Q2 -q)"
+ export TERMINFO
- In historic curses versions, delays embedded in the
- capabilities cr, ind, cub1, ff and tab activated
- corresponding delay bits in the UNIX tty driver. In this
- implementation, all padding is done by NUL sends. This
- method is slightly more expensive, but narrows the
- interface to the UNIX kernel significantly and increases
- the package's portability correspondingly.
+ The compiled description is used if it corresponds to
+ the terminal identified by the TERM variable.
+ Setting TERMINFO is the simplest, but not the only way to
+ set location of the default terminal database. The com-
+ plete list of database locations in order follows:
-
-
NOTES
- The header file <curses.h> automatically includes the
- header files <stdio.h> and <unctrl.h>.
+ o the last terminal database to which ncurses wrote,
+ if any, is searched first
- If standard output from a ncurses 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.
+ o the location specified by the TERMINFO environment
+ variable
+ o $HOME/.terminfo
-
-
AUTHORS
- Zeyd M. Ben-Halim, Eric S. Raymond, Thomas E. Dickey.
- Based on pcurses by Pavel Curtis.
+ o locations listed in the TERMINFO_DIRS environment
+ variable
+ o one or more locations whose names are configured
+ and compiled into the ncurses library, i.e.,
+ o /usr/local/ncurses/share/ter-
+ minfo:/usr/share/terminfo (corresponding to the
+ TERMINFO_DIRS variable)
+ o /usr/share/terminfo (corresponding to the TER-
+ MINFO variable)
+
+ 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 TERMINFO vari-
+ able. 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 ncurses.
+
+ If TERMCAP does not hold a file name then ncurses checks
+ the TERMPATH environment variable. This is a list of
+ filenames separated by spaces or colons (i.e., ":") on
+ Unix, semicolons on OS/2 EMX.
+ If the TERMPATH environment variable is not set, ncurses
+ 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:
+ $TERMINFO, $TERMINFO_DIRS, $TERMPATH, as well as $HOME.
+
+ Several different configurations are possible, depending
+ on the configure script options used when building
+ ncurses. There are a few main options whose effects are
+ visible to the applications developer using ncurses:
+ --disable-overwrite
+ The standard include for ncurses is as noted in SYN-
+ OPSIS:
+ #include<curses.h>
+ This option is used to avoid filename conflicts when
+ ncurses is not the main implementation of curses of
+ the computer. If ncurses is installed disabling
+ overwrite, it puts its headers in a subdirectory,
+ e.g.,
+ #include<ncurses/curses.h>
+ It also omits a symbolic link which would allow you
+ to use -lcurses to build executables.
+ --enable-widec
+ The configure script renames the library and (if the
+ --disable-overwrite option is used) puts the header
+ files in a different subdirectory. All of the
+ library names have a "w" appended to them, i.e.,
+ instead of
+ -lncurses
+ you link with
+ -lncursesw
+ You must also define _XOPEN_SOURCE_EXTENDED when com-
+ piling for the wide-character library to use the
+ extended (wide-character) functions. The curses.h
+ 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 WINDOW struc-
+ ture differs, and very few applications require more
+ than a pointer to WINDOWs. 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
+ The configure script renames the library. All of the
+ library names have a "t" appended to them (before any
+ "w" added by --enable-widec).
+ The global variables such as LINES are replaced by
+ macros to allow read-only access. At the same time,
+ setter-functions are provided to set these values.
+ Some applications (very few) may require changes to
+ work with this convention.
+ --with-shared
+ --with-normal
+ --with-debug
+ --with-profile
+ The shared and normal (static) library names differ
+ by their suffixes, e.g., libncurses.so and libn-
+ curses.a. The debug and profiling libraries add a
+ "_g" and a "_p" to the root names respectively, e.g.,
+ libncurses_g.a and libncurses_p.a.
+ --with-trace
+ The trace 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 than assum-
+ ing it is always in the debug library.
+
+ The ncurses library can be compiled with an option
+ (-DUSE_GETCAP) that falls back to the old-style /etc/term-
+ cap file if the terminal setup code cannot find a terminfo
+ entry corresponding to TERM. Use of this feature is not
+ recommended, as it essentially includes an entire termcap
+ compiler in the ncurses startup code, at significant cost
+ in core and startup cycles.
+
+ The ncurses library includes facilities for capturing
+ mouse events on certain terminals (including xterm). See
+ the curs_mouse(3x) manual page for details.
+ The ncurses library includes facilities for responding to
+ window resizing events, e.g., when running in an xterm.
+ See the resizeterm(3x) and wresize(3x) manual pages for
+ details. In addition, the library may be configured with
+ a SIGWINCH handler.
+ The ncurses 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 define_key(3x)key_defined(3x), and keyok(3x) man-
+ ual pages for details.
+
+ The ncurses library can exploit the capabilities of termi-
+ nals which implement the ISO-6429 SGR 39 and SGR 49 con-
+ trols, 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 col-
+ ored text on a background whose color is set indepen-
+ dently, providing better control over color contrasts.
+ See the default_colors(3x) manual page for details.
+ The ncurses library includes a function for directing
+ application output to a printer attached to the terminal
+ device. See the curs_print(3x) manual page for details.
+
+ The ncurses library is intended to be BASE-level confor-
+ mant with XSI Curses. The EXTENDED XSI Curses functional-
+ ity (including color support) is supported.
+ A small number of local differences (that is, individual
+ differences between the XSI Curses and ncurses calls) are
+ described in PORTABILITY sections of the library man
+ pages.
+ 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 applica-
+ tion which of several possible errors were detected.
+ Relying on this (or some other) extension will adversely
+ affect the portability of curses applications.
+
+ This implementation also contains several extensions:
+
+ o The routine has_key is not part of XPG4, nor is it
+ present in SVr4. See the curs_getch(3x) manual page
+ for details.
+
+ o The routine slk_attr is not part of XPG4, nor is it
+ present in SVr4. See the curs_slk(3x) manual page for
+ details.
+
+ o The routines getmouse, mousemask, ungetmouse, mousein-
+ terval, and wenclose relating to mouse interfacing are
+ not part of XPG4, nor are they present in SVr4. See
+ the curs_mouse(3x) manual page for details.
+
+ o The routine mcprint was not present in any previous
+ curses implementation. See the curs_print(3x) manual
+ page for details.
+
+ o The routine wresize is not part of XPG4, nor is it
+ present in SVr4. See the wresize(3x) manual page for
+ details.
+
+ o The WINDOW structure's internal details can be hidden
+ from application programs. See curs_opaque(3x) for
+ the discussion of is_scrollok, etc.
+
+ o This implementation can be configured to provide rudi-
+ mentary support for multi-threaded applications. See
+ curs_threads(3x) for details.
+
+ o This implementation can also be configured to provide
+ a set of functions which improve the ability to manage
+ multiple screens. See curs_sp_funcs(3x) for details.
+
+ In historic curses versions, delays embedded in the capa-
+ bilities cr, ind, cub1, ff and tab activated corresponding
+ delay bits in the UNIX tty driver. In this implementa-
+ tion, all padding is done by sending NUL bytes. This
+ method is slightly more expensive, but narrows the inter-
+ face to the UNIX kernel significantly and increases the
+ package's portability correspondingly.
+
+
+
+ The header file <curses.h> automatically includes the
+ header files <stdio.h> and <unctrl.h>.
+ If standard output from a ncurses program is re-directed
+ to something which is not a tty, screen updates will be
+ directed to standard error. This was an undocumented fea-
+ ture of AT&T System V Release 3 curses.
+