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
error 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 terminal
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 routine restores tty modes, moves the
cursor to the lower left-hand corner of the screen and resets the
terminal 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
These functions are described in the XSI Curses standard, Issue 4. It
specifies that portable applications must not call initscr more than
once.
Old versions of curses, e.g., BSD 4.4, may have returned a null pointer
from initscr when an error is detected, rather than exiting. It is
safe but redundant to check the return value of initscr in XSI Curses.
SEE ALSO
ncurses(3NCURSES), kernel(3NCURSES), refresh(3NCURSES), slk(3NCURSES),
util(3NCURSES)
initscr(3NCURSES)