curs_initscr(3X) curs_initscr(3X)
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 rou-tines routines
tines 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 appro-priate appropriate
priate 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 in-stead instead
stead of initscr. A program that needs to inspect capabilities, so it can continue to run in a line-oriented lineoriented
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 rou-tine routine
tine 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 appli-cations applications
cations 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
curses(3X), curs_kernel(3X), curs_refresh(3X), curs_slk(3X), curs_util(3X)
curs_initscr(3X)
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