curses - CRT screen handling and optimization package #include <curses.h>

The curses 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 is being discontinued. The curses routines emulate the curses(3X) library of System V Release 4 UNIX, and the XPG4 curses standard (XSI curses) but the curses 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. A program using these routines must be linked with the -lcurses option. The curses 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. 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. tset(1) is usually responsible for doing this. [See terminfo(\*n) 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. Note that curses does not handle overlapping windows, that's done by the panels(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 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 curses manual pages. Among which 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.) 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. 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 <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 \*d/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 \*d/a/att4424. This is useful for developing experimental definitions or when write permission in \*d 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. 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 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 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. Routines flagged with `*' are ncurses-specific, not described by XPG4 or present in SVr4.

 
curses Routine Name Manual Page Name
___________________________________________
addch curs_addch(3X)
addchnstr curs_addchstr(3X)
addchstr curs_addchstr(3X)
addnstr curs_addstr(3X)
addstr curs_addstr(3X)
attroff curs_attr(3X)
attron curs_attr(3X)
attrset curs_attr(3X)
baudrate curs_termattrs(3X)
beep curs_beep(3X)
bkgd curs_bkgd(3X)
bkgdset curs_bkgd(3X)
border curs_border(3X)
box curs_border(3X)
can_change_color curs_color(3X)
cbreak curs_inopts(3X)
clear curs_clear(3X)
clearok curs_outopts(3X)
clrtobot curs_clear(3X)
clrtoeol curs_clear(3X)
color_content curs_color(3X)
copywin curs_overlay(3X)
curs_set curs_kernel(3X)
def_prog_mode curs_kernel(3X)
def_shell_mode curs_kernel(3X)
del_curterm curs_terminfo(3X)
delay_output curs_util(3X)
delch curs_delch(3X)
deleteln curs_deleteln(3X)
delscreen curs_initscr(3X)
delwin curs_window(3X)
derwin curs_window(3X)
doupdate curs_refresh(3X)
dupwin curs_window(3X)
echo curs_inopts(3X)
echochar curs_addch(3X)
endwin curs_initscr(3X)
erase curs_clear(3X)
erasechar curs_termattrs(3X)
filter curs_util(3X)
flash curs_beep(3X)
flushinp curs_util(3X)
getbegyx curs_getyx(3X)
getch curs_getch(3X)
getmaxyx curs_getyx(3X)
getmouse curs_mouse(3X)*
getparyx curs_getyx(3X)
getstr curs_getstr(3X)
getsyx curs_kernel(3X)
getwin curs_util(3X)
getyx curs_getyx(3X)
halfdelay curs_inopts(3X)
has_colors curs_color(3X)
has_ic curs_termattrs(3X)
has_il curs_termattrs(3X)
hline curs_border(3X)
idcok curs_outopts(3X)
idlok curs_outopts(3X)
immedok curs_outopts(3X)
inch curs_inch(3X)
inchnstr curs_inchstr(3X)
inchstr curs_inchstr(3X)
init_color curs_color(3X)
init_pair curs_color(3X)
initscr curs_initscr(3X)
innstr curs_instr(3X)
insch curs_insch(3X)
insdelln curs_deleteln(3X)
insertln curs_deleteln(3X)
insnstr curs_insstr(3X)
insstr curs_insstr(3X)
instr curs_instr(3X)
intrflush curs_inopts(3X)
is_linetouched curs_touch(3X)
is_wintouched curs_touch(3X)
isendwin curs_initscr(3X)
keyname curs_util(3X)
keypad curs_inopts(3X)
killchar curs_termattrs(3X)
leaveok curs_outopts(3X)
longname curs_termattrs(3X)
meta curs_inopts(3X)
mouseinterval curs_mouse(3X)*
mousemask curs_mouse(3X)*
move curs_move(3X)
mvaddch curs_addch(3X)
mvaddchnstr curs_addchstr(3X)
mvaddchstr curs_addchstr(3X)
mvaddnstr curs_addstr(3X)
mvaddstr curs_addstr(3X)
mvcur curs_terminfo(3X)
mvdelch curs_delch(3X)
mvderwin curs_window(3X)
mvgetch curs_getch(3X)
mvgetstr curs_getstr(3X)
mvinch curs_inch(3X)
mvinchnstr curs_inchstr(3X)
mvinchstr curs_inchstr(3X)
mvinnstr curs_instr(3X)
mvinsch curs_insch(3X)
mvinsnstr curs_insstr(3X)
mvinsstr curs_insstr(3X)
mvinstr curs_instr(3X)
mvprintw curs_printw(3X)
mvscanw curs_scanw(3X)
mvwaddch curs_addch(3X)
mvwaddchnstr curs_addchstr(3X)
mvwaddchstr curs_addchstr(3X)
mvwaddnstr curs_addstr(3X)
mvwaddstr curs_addstr(3X)
mvwdelch curs_delch(3X)
mvwgetch curs_getch(3X)
mvwgetstr curs_getstr(3X)
mvwin curs_window(3X)
mvwinch curs_inch(3X)
mvwinchnstr curs_inchstr(3X)
mvwinchstr curs_inchstr(3X)
mvwinnstr curs_instr(3X)
mvwinsch curs_insch(3X)
mvwinsnstr curs_insstr(3X)
mvwinsstr curs_insstr(3X)
mvwinstr curs_instr(3X)
mvwprintw curs_printw(3X)
mvwscanw curs_scanw(3X)
napms curs_kernel(3X)
newpad curs_pad(3X)
newterm curs_initscr(3X)
newwin curs_window(3X)
nl curs_outopts(3X)
nocbreak curs_inopts(3X)
nodelay curs_inopts(3X)
noecho curs_inopts(3X)
nonl curs_outopts(3X)
noqiflush curs_inopts(3X)
noraw curs_inopts(3X)
notimeout curs_inopts(3X)
overlay curs_overlay(3X)
overwrite curs_overlay(3X)
pair_content curs_color(3X)
pechochar curs_pad(3X)
pnoutrefresh curs_pad(3X)
prefresh curs_pad(3X)
printw curs_printw(3X)
putp curs_terminfo(3X)
putwin curs_util(3X)
qiflush curs_inopts(3X)
raw curs_inopts(3X)
redrawwin curs_refresh(3X)
refresh curs_refresh(3X)
reset_prog_mode curs_kernel(3X)
reset_shell_mode curs_kernel(3X)
resetty curs_kernel(3X)
restartterm curs_terminfo(3X)
ripoffline curs_kernel(3X)
savetty curs_kernel(3X)
scanw curs_scanw(3X)
scr_dump curs_scr_dump(3X)
scr_init curs_scr_dump(3X)
scr_restore curs_scr_dump(3X)
scr_set curs_scr_dump(3X)
scrl curs_scroll(3X)
scroll curs_scroll(3X)
scrollok curs_outopts(3X)
set_curterm curs_terminfo(3X)
set_term curs_initscr(3X)
setscrreg curs_outopts(3X)
setsyx curs_kernel(3X)
setterm curs_terminfo(3X)
setupterm curs_terminfo(3X)
slk_attroff curs_slk(3X)
slk_attron curs_slk(3X)
slk_attrset curs_slk(3X)
slk_clear curs_slk(3X)
slk_init curs_slk(3X)
slk_label curs_slk(3X)
slk_noutrefresh curs_slk(3X)
slk_refresh curs_slk(3X)
slk_restore curs_slk(3X)
slk_set curs_slk(3X)
slk_touch curs_slk(3X)
standend curs_attr(3X)
standout curs_attr(3X)
start_color curs_color(3X)
subpad curs_pad(3X)
subwin curs_window(3X)
syncok curs_window(3X)
termattrs curs_termattrs(3X)
termname curs_termattrs(3X)
tgetent curs_termcap(3X)
tgetflag curs_termcap(3X)
tgetnum curs_termcap(3X)
tgetstr curs_termcap(3X)
tgoto curs_termcap(3X)
tigetflag curs_terminfo(3X)
tigetnum curs_terminfo(3X)
tigetstr curs_terminfo(3X)
timeout curs_inopts(3X)
touchline curs_touch(3X)
touchwin curs_touch(3X)
tparm curs_terminfo(3X)
tputs curs_termcap(3X)
tputs curs_terminfo(3X)
typeahead curs_inopts(3X)
unctrl curs_util(3X)
ungetch curs_getch(3X)
ungetmouse curs_mouse(3X)*
untouchwin curs_touch(3X)
use_env curs_util(3X)
vidattr curs_terminfo(3X)
vidputs curs_terminfo(3X)
vline curs_border(3X)
vwprintw curs_printw(3X)
vwscanw curs_scanw(3X)
waddch curs_addch(3X)
waddchnstr curs_addchstr(3X)
waddchstr curs_addchstr(3X)
waddnstr curs_addstr(3X)
waddstr curs_addstr(3X)
wattroff curs_attr(3X)
wattron curs_attr(3X)
wattrset curs_attr(3X)
wbkgd curs_bkgd(3X)
wbkgdset curs_bkgd(3X)
wborder curs_border(3X)
wclear curs_clear(3X)
wclrtobot curs_clear(3X)
wclrtoeol curs_clear(3X)
wcursyncup curs_window(3X)
wdelch curs_delch(3X)
wdeleteln curs_deleteln(3X)
wechochar curs_addch(3X)
wenclose curs_mouse(3X)*
werase curs_clear(3X)
wgetch curs_getch(3X)
wgetnstr curs_getstr(3X)
wgetstr curs_getstr(3X)
whline curs_border(3X)
winch curs_inch(3X)
winchnstr curs_inchstr(3X)
winchstr curs_inchstr(3X)
winnstr curs_instr(3X)
winsch curs_insch(3X)
winsdelln curs_deleteln(3X)
winsertln curs_deleteln(3X)
winsnstr curs_insstr(3X)
winsstr curs_insstr(3X)
winstr curs_instr(3X)
wmove curs_move(3X)
wnoutrefresh curs_refresh(3X)
wprintw curs_printw(3X)
wredrawln curs_refresh(3X)
wrefresh curs_refresh(3X)
wresize curs_resize(3x)*
wscanw curs_scanw(3X)
wscrl curs_scroll(3X)
wsetscrreg curs_outopts(3X)
wstandend curs_attr(3X)
wstandout curs_attr(3X)
wsyncdown curs_window(3X)
wsyncup curs_window(3X)
wtimeout curs_inopts(3X)
wtouchln curs_touch(3X)
wvline curs_border(3X)

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, getmaxyx. The 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. terminfo(\*n) and 3X pages whose names begin "curs_" for detailed routine descriptions. The curses library can be compiled with an option (-DTERMCAP_FILE) 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 curses startup code, at significant cost in core and startup cycles. Compiling with -DTERMCAP_FILE changes the library's initialization sequence in a way intended to mimic the behavior of 4.4BSD curses. If there is no local or system terminfo entry matching TERM, then the library looks for termcap entries in the following places: (1) if TERMINFO is undefined, in the file named by TERMCAP_FILE; (2) if TERMINFO is defined and begins with a slash, it is interpreted as the name of a termcap file to search for TERM; (3) otherwise, if TERMINFO has a leading string that looks like a terminal entry name list, and it matches TERM, the contents of TERMINFO is interpreted as a termcap; (4) if TERMINFO looks like a termcap but doesn't match TERM, the termcap file is searched for among the colon-separated paths in the environment variable TERMPATHS if that is defined, and in ~/.termcap and the file value of TERMCAP_FILE otherwise. Versions of curses compiled on PC clones support display of the PC ROM characters (including ROM characters 0-31, which stock SVr4 curses cannot display). See the EXTENSIONS sections of curs_addch(3x) and curs_attr(3x). The curses 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: addnwstr, addwstr, mvaddnwstr, mvwaddnwstr, mvaddwstr, waddnwstr, waddwstr, add_wch, wadd_wch, mvadd_wch, mvwadd_wch, add_wchnstr, add_wchstr, wadd_wchnstr, wadd_wchstr, mvadd_wchnstr, mvadd_wchstr, mvwadd_wchnstr, mvwadd_wchstr, bkgrndset, bkgrnd, getbkgrnd, wbkgrnd, wbkgrndset, wgetbkgrnd, border_set, wborder_set, box_set, hline_set, mvhline_set, mvvline_set, mvwhline_set, mvwvline_set, whline_set, vhline_set, wvline_set, echo_wchar, wecho_wchar, erasewchar, killwchar, get_wch, mvget_wch, mvwget_ch, wget_wch, getwchtype, get_wstr, getn_wstr, wget_wstr, wgetn_wstr, mvget_wstr, mvgetn_wstr, mvwget_wstr, mvwgetn_wstr, innwstr, inwstr, winnwstr, winwstr, mvinnwstr, mvinwstr, mvwinnwstr, mvwinwstr, ins_nwstr, ins_wstr, mvins_nwstr, mvins_wstr, mvwins_nwstr, mvwins_wstr, wins_nwstr, wins_wstr, ins_wch, wins_wch, mvins_wch, mvwins_wch, in_wch, win_wch, mvin_wch, mvwin_wch, inwchstr, inwchnstr, winwchstr, winwchnstr, mvinwchstr, mvinwchnstr, mvinwchstr, mvwinwchnstr.

A small number of local differences (that is, individual differences between the XSI Curses and curses calls) are described in PORTABILITY sections of the library man pages.

The terminfo format supported by curses is binary-compatible with SVr4, but not conformant with XSI curses. This is because the XSI Curses drafters, in a remarkable fit of braindamage, changed the undocumented SVr4 capability getm from a string to a boolean, changing the binary offsets of all capabilities after it in the SVr4 order and making it impossible for any SVr4-compatible implementation to be fully conformant.

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.

The routine wresize is not part of XPG4, nor is it present in SVr4. See the curs_resize(3X) manual page for details.

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.

In the XSI standard and SVr4 manual pages, many entry points have prototype arguments of the for char *const (or cchar_t *const, or wchar_t *const, or void *const). Depending on one's interpretation of the ANSI C standard (see section 3.5.4.1), these declarations are either (a) meaningless, or (b) meaningless and illegal. The declaration const char *x is a modifiable pointer to unmodifiable data, but char *const x' is an unmodifiable pointer to modifiable data. Given that C passes arguments by value, <type> *const as a formal type is at best dubious. Some compilers choke on the prototypes. Therefore, in this implementation, they have been changed to const <type> * globally.

The header file <curses.h> automatically includes the header files <stdio.h> and <unctrl.h>. If standard output from a curses 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. Zeyd M. Ben-Halim, Eric S. Raymond. Descends from the original pcurses by Pavel Curtis. #
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