NAME

Curses - terminal screen handling and optimization

SYNOPSIS

 use Curses;

 initscr;
 ...
 endwin;


Curses::supports_function($function);
Curses::supports_contsant($constant);

DESCRIPTION

Curses is the interface between Perl and your system's curses(3) library. For descriptions on the usage of a given function, variable, or constant, consult your system's documentation, as such information invariably varies (:-) between different curses(3) libraries and operating systems. This document describes the interface itself, and assumes that you already know how your system's curses(3) library works.

Unified Functions

Many curses(3) functions have variants starting with the prefixes w-, mv-, and/or wmv-. These variants differ only in the explicit addition of a window, or by the addition of two coordinates that are used to move the cursor first. For example, addch() has three other variants: waddch(), mvaddch(), and mvwaddch(). The variants aren't very interesting; in fact, we could roll all of the variants into original function by allowing a variable number of arguments and analyzing the argument list for which variant the user wanted to call.

Unfortunately, curses(3) predates varargs(3), so in C we were stuck with all the variants. However, Curses is a Perl interface, so we are free to "unify" these variants into one function. The section "Supported Functions" below lists all curses(3) function supported by Curses, along with a column listing if it is unified. If so, it takes a varying number of arguments as follows:

    function( [win], [y, x], args );

    win is an optional window argument, defaulting to stdscr if not specified.

    y, x is an optional coordinate pair used to move the cursor, defaulting to no move if not specified.

    args are the required arguments of the function. These are the arguments you would specify if you were just calling the base function and not any of the variants.

This makes the variants obsolete, since their functionality has been merged into a single function, so Curses does not define them by default. You can still get them if you want, by setting the variable $Curses::OldCurses to a non-zero value before using the Curses package. See "Perl 4.X cursperl Compatibility" for an example of this.

Objects

Objects are supported. Example:

$win = new Curses;
$win->addstr(10, 10, 'foo');
$win->refresh;
...

Any function that has been marked as unified (see "Supported Functions" below and "Unified Functions" above) can be called as a method for a Curses object.

Do not use initscr() if using objects, as the first call to get a new Curses will do it for you.

Security Concerns

It has always been the case with the curses functions, but please note that the following functions:

getstr()   (and optional wgetstr(), mvgetstr(), and mvwgetstr())
inchstr()  (and optional winchstr(), mvinchstr(), and mvwinchstr())
instr()    (and optional winstr(), mvinstr(), and mvwinstr())

are subject to buffer overflow attack. This is because you pass in the buffer to be filled in, which has to be of finite length, but there is no way to stop a bad guy from typing.

In order to avoid this problem, use the alternate functions:

getnstr()
inchnstr()
innstr()

which take an extra "size of buffer" argument.

COMPATIBILITY

Perl 4.X cursperl Compatibility

Curses has been written to take advantage of the new features of Perl. I felt it better to provide an improved curses programming environment rather than to be 100% compatible. However, many old curseperl applications will probably still work by starting the script with:

BEGIN { $Curses::OldCurses = 1; }
use Curses;

Any old application that still does not work should print an understandable error message explaining the problem.

Some functions and variables are not supported by Curses, even with the BEGIN line. They are listed under "curses(3) items not supported by Curses".

The variables $stdscr and $curscr are also available as functions stdscr and curscr. This is because of a Perl bug. See the BUGS section for details.

Incompatibilities with previous versions of Curses

In previous versions of this software, some Perl functions took a different set of parameters than their C counterparts. This is no longer true. You should now use getstr($str) and getyx($y, $x) instead of $str = getstr() and ($y, $x) = getyx().

Incompatibilities with other Perl programs

    menu.pl, v3.0 and v3.1
	There were various interaction problems between these two
	releases and Curses.  Please upgrade to the latest version
	(v3.3 as of 3/16/96).

DIAGNOSTICS

  • Curses function '%s' called with too %s arguments at ...

    You have called a Curses function with a wrong number of arguments.

  • argument %d to Curses function '%s' is not a Curses %s at ... =item * argument is not a Curses %s at ...

    The argument you gave to the function wasn't what it wanted.

    This probably means that you didn't give the right arguments to a unified function. See the DESCRIPTION section on "Unified Functions" for more information.

  • Curses function '%s' is not defined by your vendor at ...

    You have a Curses function in your code that your system's curses(3) library doesn't define.

  • Curses variable '%s' is not defined by your vendor at ...

    You have a Curses variable in your code that your system's curses(3) library doesn't define.

  • Curses constant '%s' is not defined by your vendor at ...

    You have a Curses constant in your code that your system's curses(3) library doesn't define.

  • Curses::Vars::FETCH called with bad index at ... =item * Curses::Vars::STORE called with bad index at ...

    You've been playing with the tie interface to the Curses variables. Don't do that. :-)

  • Anything else

    Check out the perldiag man page to see if the error is in there.

BUGS

If you use the variables $stdscr and $curscr instead of their functional counterparts (stdscr and curscr), you might run into a bug in Perl where the "magic" isn't called early enough. This is manifested by the Curses package telling you $stdscr isn't a window. One workaround is to put a line like $stdscr = $stdscr near the front of your program.

Probably many more.

AUTHOR

William Setzer <William_Setzer@ncsu.edu>

SYNOPSIS OF PERL CURSES SUPPORT

Supported Functions

Supported            Unified?     Supported via $OldCurses[*]
---------            --------     ------------------------
addch                  Yes        waddch mvaddch mvwaddch
echochar               Yes        wechochar
addchstr               Yes        waddchstr mvaddchstr mvwaddchstr
addchnstr              Yes        waddchnstr mvaddchnstr mvwaddchnstr
addstr                 Yes        waddstr mvaddstr mvwaddstr
addnstr                Yes        waddnstr mvaddnstr mvwaddnstr
attroff                Yes        wattroff
attron                 Yes        wattron
attrset                Yes        wattrset
standend               Yes        wstandend
standout               Yes        wstandout
attr_get               Yes        wattr_get
attr_off               Yes        wattr_off
attr_on                Yes        wattr_on
attr_set               Yes        wattr_set
chgat                  Yes        wchgat mvchgat mvwchgat
COLOR_PAIR              No
PAIR_NUMBER             No
beep                    No
flash                   No
bkgd                   Yes        wbkgd
bkgdset                Yes        wbkgdset
getbkgd                Yes
border                 Yes        wborder
box                    Yes
hline                  Yes        whline mvhline mvwhline
vline                  Yes        wvline mvvline mvwvline
erase                  Yes        werase
clear                  Yes        wclear
clrtobot               Yes        wclrtobot
clrtoeol               Yes        wclrtoeol
start_color             No
init_pair               No
init_color              No
has_colors              No
can_change_color        No
color_content           No
pair_content            No
delch                  Yes        wdelch mvdelch mvwdelch
deleteln               Yes        wdeleteln
insdelln               Yes        winsdelln
insertln               Yes        winsertln
getch                  Yes        wgetch mvgetch mvwgetch
ungetch                 No
has_key                 No
KEY_F                   No
getstr                 Yes        wgetstr mvgetstr mvwgetstr
getnstr                Yes        wgetnstr mvgetnstr mvwgetnstr
getyx                  Yes
getparyx               Yes
getbegyx               Yes
getmaxyx               Yes
inch                   Yes        winch mvinch mvwinch
inchstr                Yes        winchstr mvinchstr mvwinchstr
inchnstr               Yes        winchnstr mvinchnstr mvwinchnstr
initscr                 No
endwin                  No
isendwin                No
newterm                 No
set_term                No
delscreen               No
cbreak                  No
nocbreak                No
echo                    No
noecho                  No
halfdelay               No
intrflush              Yes
keypad                 Yes
meta                   Yes
nodelay                Yes
notimeout              Yes
raw                     No
noraw                   No
qiflush                 No
noqiflush               No
timeout                Yes        wtimeout
typeahead               No
insch                  Yes        winsch mvinsch mvwinsch
insstr                 Yes        winsstr mvinsstr mvwinsstr
insnstr                Yes        winsnstr mvinsnstr mvwinsnstr
instr                  Yes        winstr mvinstr mvwinstr
innstr                 Yes        winnstr mvinnstr mvwinnstr
def_prog_mode           No
def_shell_mode          No
reset_prog_mode         No
reset_shell_mode        No
resetty                 No
savetty                 No
getsyx                  No
setsyx                  No
curs_set                No
napms                   No
move                   Yes        wmove
clearok                Yes
idlok                  Yes
idcok                  Yes
immedok                Yes
leaveok                Yes
setscrreg              Yes        wsetscrreg
scrollok               Yes
nl                      No
nonl                    No
overlay                 No
overwrite               No
copywin                 No
newpad                  No
subpad                  No
prefresh                No
pnoutrefresh            No
pechochar               No
refresh                Yes        wrefresh
noutrefresh            Yes        wnoutrefresh
doupdate                No
redrawwin              Yes
redrawln               Yes        wredrawln
scr_dump                No
scr_restore             No
scr_init                No
scr_set                 No
scroll                 Yes
scrl                   Yes        wscrl
slk_init                No
slk_set                 No
slk_refresh             No
slk_noutrefresh         No
slk_label               No
slk_clear               No
slk_restore             No
slk_touch               No
slk_attron              No
slk_attrset             No
slk_attr                No
slk_attroff             No
slk_color               No
baudrate                No
erasechar               No
has_ic                  No
has_il                  No
killchar                No
longname                No
termattrs               No
termname                No
touchwin               Yes
touchline              Yes
untouchwin             Yes
touchln                Yes        wtouchln
is_linetouched         Yes
is_wintouched          Yes
unctrl                  No
keyname                 No
filter                  No
use_env                 No
putwin                  No
getwin                  No
delay_output            No
flushinp                No
newwin                  No
delwin                 Yes
mvwin                  Yes
subwin                 Yes
derwin                 Yes
mvderwin               Yes
dupwin                 Yes
syncup                 Yes        wsyncup
syncok                 Yes
cursyncup              Yes        wcursyncup
syncdown               Yes        wsyncdown
getmouse                No
ungetmouse              No
mousemask               No
enclose                Yes        wenclose
mouse_trafo            Yes        wmouse_trafo
mouseinterval           No
BUTTON_RELEASE          No
BUTTON_PRESS            No
BUTTON_CLICK            No
BUTTON_DOUBLE_CLICK     No
BUTTON_TRIPLE_CLICK     No
BUTTON_RESERVED_EVENT   No
use_default_colors      No
assume_default_colors   No
define_key              No
keybound                No
keyok                   No
resizeterm              No
resize                 Yes        wresize
getmaxy                Yes
getmaxx                Yes
flusok                 Yes
getcap                  No
touchoverlap            No
new_panel               No
bottom_panel            No
top_panel               No
show_panel              No
update_panels           No
hide_panel              No
panel_window            No
replace_panel           No
move_panel              No
panel_hidden            No
panel_above             No
panel_below             No
set_panel_userptr       No
panel_userptr           No
del_panel               No
set_menu_fore           No
menu_fore               No
set_menu_back           No
menu_back               No
set_menu_grey           No
menu_grey               No
set_menu_pad            No
menu_pad                No
pos_menu_cursor         No
menu_driver             No
set_menu_format         No
menu_format             No
set_menu_items          No
menu_items              No
item_count              No
set_menu_mark           No
menu_mark               No
new_menu                No
free_menu               No
menu_opts               No
set_menu_opts           No
menu_opts_on            No
menu_opts_off           No
set_menu_pattern        No
menu_pattern            No
post_menu               No
unpost_menu             No
set_menu_userptr        No
menu_userptr            No
set_menu_win            No
menu_win                No
set_menu_sub            No
menu_sub                No
scale_menu              No
set_current_item        No
current_item            No
set_top_row             No
top_row                 No
item_index              No
item_name               No
item_description        No
new_item                No
free_item               No
set_item_opts           No
item_opts_on            No
item_opts_off           No
item_opts               No
item_userptr            No
set_item_userptr        No
set_item_value          No
item_value              No
item_visible            No
menu_request_name       No
menu_request_by_name    No
set_menu_spacing        No
menu_spacing            No
pos_form_cursor         No
data_ahead              No
data_behind             No
form_driver             No
set_form_fields         No
form_fields             No
field_count             No
move_field              No
new_form                No
free_form               No
set_new_page            No
new_page                No
set_form_opts           No
form_opts_on            No
form_opts_off           No
form_opts               No
set_current_field       No
current_field           No
set_form_page           No
form_page               No
field_index             No
post_form               No
unpost_form             No
set_form_userptr        No
form_userptr            No
set_form_win            No
form_win                No
set_form_sub            No
form_sub                No
scale_form              No
set_field_fore          No
field_fore              No
set_field_back          No
field_back              No
set_field_pad           No
field_pad               No
set_field_buffer        No
field_buffer            No
set_field_status        No
field_status            No
set_max_field           No
field_info              No
dynamic_field_info      No
set_field_just          No
field_just              No
new_field               No
dup_field               No
link_field              No
free_field              No
set_field_opts          No
field_opts_on           No
field_opts_off          No
field_opts              No
set_field_userptr       No
field_userptr           No
field_arg               No
form_request_name       No
form_request_by_name    No

[*] To use any functions in this column, the variable $Curses::OldCurses must be set to a non-zero value before using the Curses package. See "Perl 4.X cursperl Compatibility" for an example of this.

Supported Variables

LINES                   COLS                    stdscr
curscr                  COLORS                  COLOR_PAIRS

Supported Constants

ERR                     OK                      ACS_BLOCK
ACS_BOARD               ACS_BTEE                ACS_BULLET
ACS_CKBOARD             ACS_DARROW              ACS_DEGREE
ACS_DIAMOND             ACS_HLINE               ACS_LANTERN
ACS_LARROW              ACS_LLCORNER            ACS_LRCORNER
ACS_LTEE                ACS_PLMINUS             ACS_PLUS
ACS_RARROW              ACS_RTEE                ACS_S1
ACS_S9                  ACS_TTEE                ACS_UARROW
ACS_ULCORNER            ACS_URCORNER            ACS_VLINE
A_ALTCHARSET            A_ATTRIBUTES            A_BLINK
A_BOLD                  A_CHARTEXT              A_COLOR
A_DIM                   A_INVIS                 A_NORMAL
A_PROTECT               A_REVERSE               A_STANDOUT
A_UNDERLINE             COLOR_BLACK             COLOR_BLUE
COLOR_CYAN              COLOR_GREEN             COLOR_MAGENTA
COLOR_RED               COLOR_WHITE             COLOR_YELLOW
KEY_A1                  KEY_A3                  KEY_B2
KEY_BACKSPACE           KEY_BEG                 KEY_BREAK
KEY_BTAB                KEY_C1                  KEY_C3
KEY_CANCEL              KEY_CATAB               KEY_CLEAR
KEY_CLOSE               KEY_COMMAND             KEY_COPY
KEY_CREATE              KEY_CTAB                KEY_DC
KEY_DL                  KEY_DOWN                KEY_EIC
KEY_END                 KEY_ENTER               KEY_EOL
KEY_EOS                 KEY_EXIT                KEY_F0
KEY_FIND                KEY_HELP                KEY_HOME
KEY_IC                  KEY_IL                  KEY_LEFT
KEY_LL                  KEY_MARK                KEY_MAX
KEY_MESSAGE             KEY_MIN                 KEY_MOVE
KEY_NEXT                KEY_NPAGE               KEY_OPEN
KEY_OPTIONS             KEY_PPAGE               KEY_PREVIOUS
KEY_PRINT               KEY_REDO                KEY_REFERENCE
KEY_REFRESH             KEY_REPLACE             KEY_RESET
KEY_RESTART             KEY_RESUME              KEY_RIGHT
KEY_SAVE                KEY_SBEG                KEY_SCANCEL
KEY_SCOMMAND            KEY_SCOPY               KEY_SCREATE
KEY_SDC                 KEY_SDL                 KEY_SELECT
KEY_SEND                KEY_SEOL                KEY_SEXIT
KEY_SF                  KEY_SFIND               KEY_SHELP
KEY_SHOME               KEY_SIC                 KEY_SLEFT
KEY_SMESSAGE            KEY_SMOVE               KEY_SNEXT
KEY_SOPTIONS            KEY_SPREVIOUS           KEY_SPRINT
KEY_SR                  KEY_SREDO               KEY_SREPLACE
KEY_SRESET              KEY_SRIGHT              KEY_SRSUME
KEY_SSAVE               KEY_SSUSPEND            KEY_STAB
KEY_SUNDO               KEY_SUSPEND             KEY_UNDO
KEY_UP                  KEY_MOUSE               BUTTON1_RELEASED
BUTTON1_PRESSED         BUTTON1_CLICKED         BUTTON1_DOUBLE_CLICKED
BUTTON1_TRIPLE_CLICKED  BUTTON1_RESERVED_EVENT  BUTTON2_RELEASED
BUTTON2_PRESSED         BUTTON2_CLICKED         BUTTON2_DOUBLE_CLICKED
BUTTON2_TRIPLE_CLICKED  BUTTON2_RESERVED_EVENT  BUTTON3_RELEASED
BUTTON3_PRESSED         BUTTON3_CLICKED         BUTTON3_DOUBLE_CLICKED
BUTTON3_TRIPLE_CLICKED  BUTTON3_RESERVED_EVENT  BUTTON4_RELEASED
BUTTON4_PRESSED         BUTTON4_CLICKED         BUTTON4_DOUBLE_CLICKED
BUTTON4_TRIPLE_CLICKED  BUTTON4_RESERVED_EVENT  BUTTON_CTRL
BUTTON_SHIFT            BUTTON_ALT              ALL_MOUSE_EVENTS
REPORT_MOUSE_POSITION   NCURSES_MOUSE_VERSION   E_OK
E_SYSTEM_ERROR          E_BAD_ARGUMENT          E_POSTED
E_CONNECTED             E_BAD_STATE             E_NO_ROOM
E_NOT_POSTED            E_UNKNOWN_COMMAND       E_NO_MATCH
E_NOT_SELECTABLE        E_NOT_CONNECTED         E_REQUEST_DENIED
E_INVALID_FIELD         E_CURRENT               REQ_LEFT_ITEM
REQ_RIGHT_ITEM          REQ_UP_ITEM             REQ_DOWN_ITEM
REQ_SCR_ULINE           REQ_SCR_DLINE           REQ_SCR_DPAGE
REQ_SCR_UPAGE           REQ_FIRST_ITEM          REQ_LAST_ITEM
REQ_NEXT_ITEM           REQ_PREV_ITEM           REQ_TOGGLE_ITEM
REQ_CLEAR_PATTERN       REQ_BACK_PATTERN        REQ_NEXT_MATCH
REQ_PREV_MATCH          MIN_MENU_COMMAND        MAX_MENU_COMMAND
O_ONEVALUE              O_SHOWDESC              O_ROWMAJOR
O_IGNORECASE            O_SHOWMATCH             O_NONCYCLIC
O_SELECTABLE            REQ_NEXT_PAGE           REQ_PREV_PAGE
REQ_FIRST_PAGE          REQ_LAST_PAGE           REQ_NEXT_FIELD
REQ_PREV_FIELD          REQ_FIRST_FIELD         REQ_LAST_FIELD
REQ_SNEXT_FIELD         REQ_SPREV_FIELD         REQ_SFIRST_FIELD
REQ_SLAST_FIELD         REQ_LEFT_FIELD          REQ_RIGHT_FIELD
REQ_UP_FIELD            REQ_DOWN_FIELD          REQ_NEXT_CHAR
REQ_PREV_CHAR           REQ_NEXT_LINE           REQ_PREV_LINE
REQ_NEXT_WORD           REQ_PREV_WORD           REQ_BEG_FIELD
REQ_END_FIELD           REQ_BEG_LINE            REQ_END_LINE
REQ_LEFT_CHAR           REQ_RIGHT_CHAR          REQ_UP_CHAR
REQ_DOWN_CHAR           REQ_NEW_LINE            REQ_INS_CHAR
REQ_INS_LINE            REQ_DEL_CHAR            REQ_DEL_PREV
REQ_DEL_LINE            REQ_DEL_WORD            REQ_CLR_EOL
REQ_CLR_EOF             REQ_CLR_FIELD           REQ_OVL_MODE
REQ_INS_MODE            REQ_SCR_FLINE           REQ_SCR_BLINE
REQ_SCR_FPAGE           REQ_SCR_BPAGE           REQ_SCR_FHPAGE
REQ_SCR_BHPAGE          REQ_SCR_FCHAR           REQ_SCR_BCHAR
REQ_SCR_HFLINE          REQ_SCR_HBLINE          REQ_SCR_HFHALF
REQ_SCR_HBHALF          REQ_VALIDATION          REQ_NEXT_CHOICE
REQ_PREV_CHOICE         MIN_FORM_COMMAND        MAX_FORM_COMMAND
NO_JUSTIFICATION        JUSTIFY_LEFT            JUSTIFY_CENTER
JUSTIFY_RIGHT           O_VISIBLE               O_ACTIVE
O_PUBLIC                O_EDIT                  O_WRAP
O_BLANK                 O_AUTOSKIP              O_NULLOK
O_PASSOK                O_STATIC                O_NL_OVERLOAD
O_BS_OVERLOAD           

curses(3) functions not supported by Curses

tstp _putchar fullname scanw wscanw mvscanw mvwscanw ripoffline
setupterm setterm set_curterm del_curterm restartterm tparm tputs
putp vidputs vidattr mvcur tigetflag tigetnum tigetstr tgetent
tgetflag tgetnum tgetstr tgoto tputs
set_item_init item_init set_item_term item_term set_menu_init
menu_init set_menu_term menu_term

form(3) functions not supported by Curses

new_fieldtype free_fieldtype set_fieldtype_arg
set_fieldtype_choice link_fieldtype set_form_init form_init
set_form_term form_term set_field_init field_init set_field_term
field_term set_field_type field_type