Ubuntu Manpage: initscr, newterm, endwin, isendwin, set_term, delscreen - curses screen initialization and manipulation

Provided by: ncurses-doc_5.9+20140118-1ubuntu1_all

NAME

       initscr, newterm, endwin, isendwin, set_term, delscreen - curses screen initialization and manipulation
       routines

SYNOPSIS

       #include <curses.h>

       WINDOW *initscr(void);
       int endwin(void);
       bool isendwin(void);
       SCREEN *newterm(char *type, FILE *outfd, FILE *infd);
       SCREEN *set_term(SCREEN *new);
       void delscreen(SCREEN* sp);

DESCRIPTION

initscr is normally the first curses routine to call when initializing a program. A few special routines
sometimes need to be called before it; these are slk_init, filter, ripoffline, use_env. For multiple-
terminal applications, newterm may be called before initscr.

The initscr code determines the terminal type and initializes all curses data structures. initscr also
causes the first call to refresh to clear the screen. If errors occur, initscr writes an appropriate er‐
ror message to standard error and exits; otherwise, a pointer is returned to stdscr.

A program that outputs to more than one terminal should use the newterm routine for each terminal instead
of initscr. A program that needs to inspect capabilities, so it can continue to run in a line-oriented
mode if the terminal cannot support a screen-oriented program, would also use newterm. The routine
newterm should be called once for each terminal. It returns a variable of type SCREEN * which should be
saved as a reference to that terminal. The arguments are the type of the terminal to be used in place of
$TERM, a file pointer for output to the terminal, and another file pointer for input from the terminal
(if type is NULL, $TERM will be used). The program must also call endwin for each terminal being used
before exiting from curses. If newterm is called more than once for the same terminal, the first termi‐
nal referred to must be the last one for which endwin is called.

A program should always call endwin before exiting or escaping from curses mode temporarily. This rou‐
tine restores tty modes, moves the cursor to the lower left-hand corner of the screen and resets the ter‐
minal into the proper non-visual mode. Calling refresh or doupdate after a temporary escape causes the
program to resume visual mode.

The isendwin routine returns TRUE if endwin has been called without any subsequent calls to wrefresh, and
FALSE otherwise.

The set_term routine is used to switch between different terminals. The screen reference new becomes the
new current terminal. The previous terminal is returned by the routine. This is the only routine which
manipulates SCREEN pointers; all other routines affect only the current terminal.

The delscreen routine frees storage associated with the SCREEN data structure. The endwin routine does
not do this, so delscreen should be called after endwin if a particular SCREEN is no longer needed.

RETURN VALUE

       endwin returns the integer ERR upon failure and OK upon successful completion.

       Routines that return pointers always return NULL on error.

       X/Open  defines  no error conditions.  In this implementation endwin returns an error if the terminal was
       not initialized.

NOTES

       Note that initscr and newterm may be macros.

PORTABILITY