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CURSES_SCREEN(3) NetBSD Library Functions Manual CURSES_SCREEN(3)
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curses_screen, filter, ripoffline, use_env, newterm, set_term, delscreen,
endwin, initscr, isendwin, is_term_resized, resize_term, resizeterm,
setterm, set_tabsize -- curses terminal and screen routines
Curses Library (libcurses, -lcurses)
ripoffline(int line, int (*init)(WINDOW *win, int cols));
newterm(char *type, FILE *outfd, FILE *infd);
is_term_resized(int lines, int cols);
resize_term(int lines, int cols);
resizeterm(int lines, int cols);
extern int LINES;
extern int COLS;
These functions initialize terminals and screens.
The newterm() function initialises the curses data structures and point-
ers ready for use by curses. The type argument points to a terminfo(5)
entry, or it may be NULL in which case the TERM environment variable is
used. The outfd and infd are the output and input file descriptors for
the terminal. The newterm() function must only be called once per ter-
The set_term() function can be used to switch between the screens defined
by calling newterm(), a pointer to the previous screen structure that was
in use will be returned on success.
Calling delscreen() will destroy the given screen and free all allocated
Calling endwin() will end the curses session and restore the saved termi-
The curses session must be initialised by calling initscr() which saves
the current terminal state and sets up the terminal and internal data
structures to support the curses application. This function call must
be, with few exceptions, the first Curses library call made. The excep-
tion to this rule is the newterm() call which may be called prior to
initscr(). The size of the curses screen is determined by checking the
tty(4) size and then the terminfo(5) entries for the terminal type. If
the environment variables LINES or COLUMNS are set, then these will be
When either newterm() or initscr() are called, the Curses library sets up
signal handlers for SIGTSTP and SIGWINCH. If a signal handler is already
installed for SIGWINCH, this will also be called when the Curses library
handler is called.
The isendwin() function can be used to determine whether or not a refresh
of the screen has occurred since the last call to endwin().
The size of the screen may be changed by calling resize_term() with the
updated number of lines and columns. This will resize the curses inter-
nal data structures to accommodate the changed terminal geometry. The
curscr and stdscr windows and any of their subwindows will be resized to
fit the new screen size. The application must redraw the screen after a
call to resize_term(). The resizeterm() function is a wrapper for
resize_term() and adjusts other structure data that handles window dimen-
sions. The is_term_resized() function tests if either of the above func-
tions need to be called.
The setterm() function sets the terminal type for the current screen to
the one passed, initialising all the curses internal data structures with
information related to the named terminal. The name argument must be a
valid name or alias in the terminfo(5) database for this function to suc-
The filter() function changes the way the terminal is initialised. A
subsequent call to initscr() or newterm() performs the following addi-
· Disable use of clear, cud, cud1, cup, cuu, cuu1 and vpa.
· Set the value of the home string to the value of the cr string.
· Set lines equal to 1.
The ripoffline() function will rip a line from stdscr at the top if line
is positive, or at the bottom if negative. When initscr() or newterm()
is called, a window will be created for each line ripped and passed to
the init function pointer alongwith the number of columns in the window.
This init function cannot use the LINES or COLS variables and cannot call
wrefresh(3) or doupdate(3), but may call wnoutrefresh(3). ripoffline()
can be called up to five times.
The use_env() function determines whether the environment variables LINES
and COLUMNS override the normal values. The default is true. Any call
to use_env() must precede calls to initscr(), newterm(), or setupterm().
The set_tabsize() function will set TABSIZE of the current screen to
Functions returning pointers will return NULL if an error is detected
with the exception of initscr() which will log a diagnostic to standard
error output and then call exit(3). The functions that return an int
will return one of the following values:
OK The function completed successfully.
ERR An error occurred in the function.
curses_window(3), tty(4), terminfo(5), signal(7)
The NetBSD Curses library complies with the X/Open Curses specification,
part of the Single Unix Specification.
The Curses package appeared in 4.0BSD. The resizeterm() function is a
ncurses extension to the Curses library and was added in NetBSD 1.6. The
is_term_resized(), resize_term() and set_tabsize() functions are ncurses
extension to the Curses library and was added in NetBSD 8.0.
There is currently an issue with cursor movement in a 1 line sized window
which causes the screen to scroll up. This can obviously be seen when
NetBSD 9.99 March 12, 2020 NetBSD 9.99
Modified for NetBSD
by Kimmo Suominen