| CURSES(3CURSES) | Curses Library Functions | CURSES(3CURSES) |
curses - CRT screen handling and optimization package
cc [ flag... ] file.. .-lcurses [ library... ] #include <curses.h>
The curses library routines give the user a terminal-independent method of updating character screens with reasonable optimization.
The curses package allows: 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 access; and access to low-level curses 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:
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 tput init command after the shell environment variable TERM has been exported. (See terminfo(5) for further details.)
The curses 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(3CURSES).
Windows are referred to by variables declared as WINDOW *. These data structures are manipulated with routines described on 3CURSES pages (whose names begin "curs_"). Among which the most basic routines are move(3CURSES) and addch(3CURSES). 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.
After using routines to manipulate a window, refresh(3CURSES) 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. These are windows which are not constrained to the size of the screen and whose contents need not be completely displayed. See curs_pad(3CURSES) for more information.
In addition to drawing characters on the screen, video attributes and colors may be included, 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 <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 of a screen is changeable.
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/lib/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
/usr/share/lib/terminfo/a/att4424.
This is useful for developing experimental definitions or when write permission in /usr/share/lib/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.
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 curscr can be used in only a few routines.
The number of bytes and the number of columns to hold a character from the supplementary character set is locale-specific (locale category LC_CTYPE) and can be specified in the character class table.
For editing, operating at the character level is entirely appropriate. For screen formatting, arbitrary movement of characters on screen is not desirable.
Overwriting characters (addch, for example) operates on a screen level. Overwriting a character by a character that requires a different number of columns may produce orphaned columns. These orphaned columns are filled with background characters.
Inserting characters (insch, for example) operates on a character level (that is, at the character boundaries). The specified character is inserted right before the character, regardless of which column of a character the cursor points to. Before insertion, the cursor position is adjusted to the first column of the character.
As with inserting characters, deleting characters (delch, for example) operates on a character level (that is, at the character boundaries). The character at the cursor is deleted whichever column of the character the cursor points to. Before deletion, the cursor position is adjusted to the first column of the character.
A multi-column character cannot be put on the last column of a line. When such attempts are made, the last column is set to the background character. In addition, when such an operation creates orphaned columns, the orphaned columns are filled with background characters.
Overlapping and overwriting a window follows the operation of overwriting characters around its edge. The orphaned columns, if any, are handled as in the character operations.
The cursor is allowed to be placed anywhere in a window. If the insertion or deletion is made when the cursor points to the second or later column position of a character that holds multiple columns, the cursor is adjusted to the first column of the character before the insertion or deletion.
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.
The routines prefixed with mv require an x and y coordinate to move to before performing the appropriate action. The mv routines imply a call to move(3CURSES) 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 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
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.
The following table lists each curses routine and the name of the manual page on which it is described.
curses Routine Name
addch
addchnstr
addchstr
addnstr
addnwstr
addstr
addwch
addwchnstr
addwchstr
addwstr
adjcurspos
attroff
attron
attrset
baudrate
beep
bkgd
bkgdset
border
box
can_change_color
cbreak
clear
clearok
clrtobot
clrtoeol
color_content
copywin
curs_set
def_prog_mode
def_shell_mode
del_curterm
delay_output
delch
deleteln
delscreen
delwin
derwin
doupdate
dupwin
echo
echochar
echowchar
endwin
erase
erasechar
filter
flash
flushinp
getbegyx
getch
getmaxyx
getnwstr
getparyx
getstr
getsyx
getwch
getwin
getwstr
getyx
halfdelay
has_colors
has_ic
has_il
idcok
idlok
immedok
inch
inchnstr
inchstr
init_color
init_pair
initscr
innstr
innwstr
insch
insdelln
insertln
insnstr
insnwstr
insstr
instr
inswch
inswstr
intrflush
inwch
inwchnstr
inwchstr
inwstr
is_linetouched
is_wintouched
isendwin
keyname
keypad
killchar
leaveok
longname
meta
move
movenextch
moveprevch
mvaddch
mvaddchnstr
mvaddchstr
mvaddnstr
mvaddnwstr
mvaddstr
mvaddwch
mvaddwchnstr
mvaddwchstr
mvaddwstr
mvcur
mvdelch
mvderwin
mvgetch
mvgetnwstr
mvgetstr
mvgetwch
mvgetwstr
mvinch
mvinchnstr
mvinchstr
mvinnstr
mvinnwstr
mvinsch
mvinsnstr
mvinsnwstr
mvinsstr
mvinstr
mvinswch
mvinswstr
mvinwch
mvinwchnstr
mvinwchstr
mvinwstr
mvprintw
mvscanw
mvwaddch
mvwaddchnstr
mvwaddchstr
mvwaddnstr
mvwaddnwstr
mvwaddstr
mvwaddwch
mvwaddwchnstr
mvwaddwchstr
mvwaddwstr
mvwdelch
mvwgetch
mvwgetnwstr
mvwgetstr
mvwgetwch
mvwgetwstr
mvwin
mvwinch
mvwinchnstr
mvwinchstr
mvwinnstr
mvwinnwstr
mvwinsch
mvwinsnstr
mvwinsstr
mvwinstr
mvwinswch
mvwinswstr
mvwinwch
mvwinwchnstr
mvwinwchstr
mvwinwstr
mvwprintw
mvwscanw
napms
newpad
newterm
newwin
nl
nocbreak
nodelay
noecho
nonl
noqiflush
noraw
notimeout
overlay
overwrite
pair_content
pechochar
pechowchar
pnoutrefresh
prefresh
printw
putp
putwin
qiflush
raw
redrawwin
refresh
reset_prog_mode
reset_shell_mode
resetty
restartterm
ripoffline
savetty
scanw
scr_dump
scr_init
scr_restore
scr_set
scroll
scrollok
set_curterm
set_term
setscrreg
setsyx
setterm
setupterm
slk_attroff
slk_attron
slk_attrset
slk_clear
slk_init
slk_label
slk_noutrefresh
slk_refresh
slk_restore
slk_set
slk_touch
srcl
standend
standout
start_color
subpad
subwin
syncok
termattrs
termname
tgetent
tgetflag
tgetnum
tgetstr
tgoto
tigetflag
tigetnum
tigetstr
timeout
touchline
touchwin
tparm
tputs
typeahead
unctrl
ungetch
ungetwch
untouchwin
use_env
vidattr
vidputs
vwprintw
vwscanw
waddch
waddchnstr
waddchstr
waddnstr
waddnwstr
waddstr
waddwch
waddwchnstr
waddwchstr
waddwstr
wadjcurspos
wattroff
wattron
wattrset
wbkgd
wbkgdset
wborder
wclear
wclrtobot
wclrtoeol
wcursyncup
wdelch
wdeleteln
wechochar
wechowchar
werase
wgetch
wgetnstr
wgetnwstr
wgetstr
wgetwch
wgetwstr
whline
winch
winchnstr
winchstr
winnstr
winnwstr
winsch
winsdelln
winsertln
winsnstr
winsnwstr
winsstr
winstr
winswch
winswstr
winwch
winwchnstr
winwchstr
winwstr
wmove
wmovenextch
wmoveprevch
wnoutrefresh
wprintw
wredrawln
wrefresh
wscanw
wscrl
wsetscrreg
wstandend
wstandout
wsyncdown
wsyncup
wtimeout
wtouchln
wvline
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.
All macros return the value of the w version, except setscrreg(), wsetscrreg(), getyx(), getbegyx(), and getmaxyx(). The return values of setscrreg(), wsetscrreg(), getyx(), getbegyx(), and getmaxyx() are undefined (that is, these should not be used as the right-hand side of assignment statements).
Routines that return pointers return NULL on error.
See attributes(7) for descriptions of the following attributes:
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
| MT-Level | Unsafe |
libcurses(3LIB), curses(3XCURSES), libcurses(3XCURSES), terminfo(5), attributes(7)
The header <curses.h> automatically includes the headers <stdio.h> and <unctrl.h>.
| October 23, 2001 | OmniOS |