curs_initscr 3x

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 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 initial-
       izes  all curses data structures.  initscr also causes the
       first call to refresh to clear the screen.  If errors  oc-
       cur,  initscr writes an appropriate error message to stan-
       dard 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 ter-
       minal 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.
       newterm's arguments are

       o   the type of the terminal to be used in place of $TERM,

       o   a file pointer for output to the terminal, and

       o   another file pointer for input from the terminal

       If the type parameter 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 es-
       caping from curses mode temporarily.  This routine

       o   restores tty modes,

       o   moves the cursor to the lower left-hand corner of  the
           screen and

       o   resets the terminal into the proper non-visual mode.

       Calling refresh or doupdate after a temporary escape caus-
       es 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 cur-
       rent terminal.  The previous terminal is returned  by  the
       routine.   This  is  the  only  routine  which manipulates
       SCREEN pointers; all other routines affect only  the  cur-
       rent 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 par-
       ticular 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 implementa-
       tion

       o   endwin returns an error if the terminal was  not  ini-
           tialized.

       o   newterm returns an error if it cannot allocate the da-
           ta structures for the screen,  or  for  the  top-level
           windows  within  the  screen, i.e., curscr, newscr, or
           stdscr.

       o   set_term returns no error.

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.

       If the TERM variable is missing or empty, initscr uses the
       value "unknown", which normally corresponds to a  terminal
       entry  with  the generic (gn) capability.  Generic entries
       are detected by curs_terminfo(3x) and cannot be used for full-
       screen  operation.   Other  implementations  may  handle a
       missing/empty TERM variable differently.

SEE ALSO

       curses(3x),       curs_kernel(3x),       curs_refresh(3x),
       curs_slk(3x), curs_terminfo(3x), curs_util(3x), curs_vari-
       ables(3x).



                                                       curs_initscr(3x)