The ncurses library routines give the user a terminal-
independent method of updating character screens with rea-
- sonable optimization. This implementation is ``new
- curses'' (ncurses) and is the approved replacement for
- 4.4BSD classic curses, which has been discontinued. This
- describes ncurses version 5.6 (patch 20080621).
-
- The ncurses library emulates the curses(3x) 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.
+ 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 20160514).
+
+ 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
@@ -96,13 +93,27 @@
lation; use of soft label keys; terminfo capabilities; and
access to low-level terminal-manipulation routines.
- 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 library uses the locale which the calling program has
+ initialized. That is normally done with setlocale:
+
+ 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.
+
+ 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
+ must be called before exiting.
+
+ To get character-at-a-time input without echoing (most
+ interactive, screen oriented programs want this), the fol-
+ lowing sequence should be used:
initscr();cbreak();noecho();
@@ -112,13 +123,15 @@
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
+ Before a curses program is run, the tab stops of the ter-
+ minal 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 struc-
tures, called windows, which can be thought of as two-
dimensional arrays of characters representing all or part
@@ -138,48 +151,50 @@
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
+ 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.
- 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 dis-
+ 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
+ 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
+ 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
+ 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
+ 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 pro-
- gram using curses checks for a local terminal definition
- before checking in the standard place. For example, if
+ 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
/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
+ creation of huge directories.) However, if TERMINFO is
set to $HOME/myterms, curses first checks
$HOME/myterms/a/att4424,
@@ -188,119 +203,119 @@
/usr/share/terminfo/a/att4424.
- This is useful for developing experimental definitions or
+ This is useful for developing experimental definitions or
when write permission in /usr/share/terminfo is not avail-
able.
- The integer variables LINES and COLS are defined in
- <curses.h> and will be filled in by initscr with the size
+ 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 val-
ues 1 and 0, respectively.
- The curses routines also define the WINDOW* variable
+ The curses routines also define the WINDOW* variable
curscr which is used for certain low-level operations like
- clearing and redrawing a screen containing garbage. The
+ clearing and redrawing a screen containing garbage. The
curscr can be used in only a few routines.
- RoutineandArgumentNames
- Many curses routines have two or more versions. The rou-
+
+
+ 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
- mv routines imply a call to move before the call to the
- other routine. The coordinate y always refers to the row
- (of the window), and x always refers to the column. The
+ to move to before performing the appropriate action. The
+ mv routines imply a call to move before the call to the
+ other routine. The coordinate y always refers to the row
+ (of the window), and x always refers to the column. The
upper left-hand corner is always (0,0), not (1,1).
The routines prefixed with mvw take both a window argument
- and x and y coordinates. The window argument is always
+ and x and y coordinates. The window argument is always
specified before the coordinates.
- In each case, win is the window affected, and pad is the
+ In each case, win is the window affected, and pad is the
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. 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
+ 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
+ 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
- characters. The normal (8-bit) library stores
- characters 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
- multibyte characters (See the section on
- ALTERNATECONFIGURATIONS). 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 charac-
- ters:
-
- cchar_t
- corresponds to chtype. However it is a
- structure, because more data is stored
- than can fit into an integer. The char-
- acters 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 sepa-
- rate 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 "nor-
- mal" library. There is a naming convention
- which relates many of the normal/wide vari-
- ants: a "_w" is inserted into the name. For
- example, waddch becomes wadd_wch.
-
-
- RoutineNameIndex
+ 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 com-
pletion, unless otherwise noted in the routine descrip-
tions.
- All macros return the value of the w version, except
+ 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, and getmaxyx. The
- return values of setscrreg, wsetscrreg, getyx, getbegyx,
+ return values of setscrreg, wsetscrreg, getyx, getbegyx,
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.
-
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.
- 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 ter-
- minfo entries provide this feature.
-
- COLUMNS
- Specify the width of the screen in characters.
- Applications running in a windowing environment usu-
- ally 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. 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
- 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 all use of exter-
- nal environment (including system calls) to determine
- the screen size.
-
- 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 vari-
- able 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 char-
- acter 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 imple-
- mentation provides a global variable with the same
- name. Portable applications should not rely upon the
- presence of ESCDELAY in either form, but setting the
- environment variable rather than the global variable
- does not create problems when compiling an applica-
- tion.
-
- 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 termi-
- nal's default colors are white-on-black (see
- default_colors(3x)). You may set the foreground and
- background color values with this environment vari-
- able by proving a 2-element list: foreground,back-
- ground. 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 posi-
- tive value from zero to the terminfo max_colors value
- is allowed.
-
- NCURSES_NO_HARD_TABS
- Ncurses 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 stty settings to avoid the problem.
-
- NCURSES_NO_MAGIC_COOKIES
- 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 termi-
- nals by setting this environment variable.
-
- 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 applica-
- tions. 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., tim-
- ing. Unless a hardware terminal is interfaced into a
- terminal concentrator (which does flow control), it
- (or your application) must manage dataflow, prevent-
- ing 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 ter-
- minal initialization. This is done (as in SVr4
- curses) for performance reasons. For testing pur-
- poses, 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_NO_UTF8_ACS
- During initialization, the ncurses library checks for
- special cases where VT100 line-drawing (and the cor-
- responding 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 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 termi-
- nal emulators.
-
- When setting this variable, you should set it to a
- nonzero value. Setting it to zero (or to a nonnum-
- ber) disables the special check for Linux and screen.
-
- 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 term-
- cap 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 termi-
- nal 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 file-
- names 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:
+ 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.
+
+
+
+ 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.
+
+
+
+ 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:
+
+ o the last directory to which ncurses wrote, if any,
+ is searched first
+
+ o the directory specified by the TERMINFO environment
+ variable
+
+ o $HOME/.terminfo
+
+ o directories listed in the TERMINFO_DIRS environment
+ variable
+
+ o one or more directories 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 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.
+ Normally these are stored in a directory tree, using sub-
+ directories named by the first letter of the terminal
+ names therein.
+
+ If ncurses is built with a hashed database, then each
+ entry in this list can also be the path of the correspond-
+ ing database file.
+
+ 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.
+
+
+
+ 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
@@ -1017,7 +1154,7 @@
The standard include for ncurses is as noted in SYN-OPSIS:
- #include<curses.h>
+ #include<curses.h>
This option is used to avoid filename conflicts when
ncurses is not the main implementation of curses of
@@ -1025,7 +1162,7 @@
overwrite, it puts its headers in a subdirectory,
e.g.,
- #include<ncurses/curses.h>
+ #include<ncurses/curses.h>
It also omits a symbolic link which would allow you
to use -lcurses to build executables.
@@ -1037,25 +1174,36 @@
library names have a "w" appended to them, i.e.,
instead of
- -lncurses
+ -lncurses
you link with
- -lncursesw
+ -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
- structure differs, and very few applications require
- more than a pointer to WINDOWs. If the headers are
+ 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
@@ -1077,22 +1225,20 @@
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
@@ -1122,88 +1268,141 @@
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
- independently, providing better control over color con-
- trasts. See the default_colors(3x) manual page for
- details.
+ 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
+ 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.
-
-
PORTABILITY
- The ncurses library is intended to be BASE-level confor-
+
+ 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
+ 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:
- 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 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.
- 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.
- The routines getmouse, mousemask, ungetmouse, mou-
- seinterval, and wenclose relating to mouse interfac-
- ing 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.
- 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.
- 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.
- 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.
- In historic curses versions, delays embedded in the capa-
+ 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
+ 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.
-
-
NOTES
- The header file <curses.h> automatically includes the
+
+ 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
+ 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.
-
-
AUTHORS
- Zeyd M. Ben-Halim, Eric S. Raymond, Thomas E. Dickey.
+