What happens if terminal is resized in ncurses `doupdate`?
The doupdate function in ncurses will try to update screen size if necessary:
ncurses/tty/tty_update.c:
if ((SP_PARM->_endwin == ewSuspend)
|| _nc_handle_sigwinch(SP_PARM)) {
/*
* This is a transparent extension: XSI does not address it,
* and applications need not know that ncurses can do it.
*
* Check if the terminal size has changed while curses was off
* (this can happen in an xterm, for example), and resize the
* ncurses data structures accordingly.
*/
_nc_update_screensize(SP_PARM);
}
My question is:
What happens if the terminal is resized after this check is done, but before anything is actually written to the terminal? If the function writes to the terminal in its new size but believes in its old size, will it crash the program or cause other undefined behavior?
It seems _nc_flush merely flushes displayed texts and terminal control characters to the output file descriptor. But I still have no idea what is the worst thing that can happen if there is a sizing problem. Is it always recoverable, meaning there is no crash and everything will work again once the library finds the correct terminal size?
ncurses
asked Dec 18 at 12:28
Cyker
1,36121429
add a comment |
The doupdate function in ncurses will try to update screen size if necessary:
ncurses/tty/tty_update.c:
if ((SP_PARM->_endwin == ewSuspend)
|| _nc_handle_sigwinch(SP_PARM)) {
/*
* This is a transparent extension: XSI does not address it,
* and applications need not know that ncurses can do it.
*
* Check if the terminal size has changed while curses was off
* (this can happen in an xterm, for example), and resize the
* ncurses data structures accordingly.
*/
_nc_update_screensize(SP_PARM);
}
My question is:
What happens if the terminal is resized after this check is done, but before anything is actually written to the terminal? If the function writes to the terminal in its new size but believes in its old size, will it crash the program or cause other undefined behavior?
It seems _nc_flush merely flushes displayed texts and terminal control characters to the output file descriptor. But I still have no idea what is the worst thing that can happen if there is a sizing problem. Is it always recoverable, meaning there is no crash and everything will work again once the library finds the correct terminal size?
ncurses
asked Dec 18 at 12:28
Cyker
1,36121429
The worst (and most likely) thing that can happen is that the display will be messed up. Most character cell programs have a keyboard shortcut for redrawing the screen, usually Ctrl-L. Stuff can always mess up a terminal display, so it is polite to give the user a way to request a complete repainting.
– AlexP
Dec 18 at 13:50
add a comment |
The doupdate function in ncurses will try to update screen size if necessary:
ncurses/tty/tty_update.c:
if ((SP_PARM->_endwin == ewSuspend)
|| _nc_handle_sigwinch(SP_PARM)) {
/*
* This is a transparent extension: XSI does not address it,
* and applications need not know that ncurses can do it.
*
* Check if the terminal size has changed while curses was off
* (this can happen in an xterm, for example), and resize the
* ncurses data structures accordingly.
*/
_nc_update_screensize(SP_PARM);
}
My question is:
What happens if the terminal is resized after this check is done, but before anything is actually written to the terminal? If the function writes to the terminal in its new size but believes in its old size, will it crash the program or cause other undefined behavior?
It seems _nc_flush merely flushes displayed texts and terminal control characters to the output file descriptor. But I still have no idea what is the worst thing that can happen if there is a sizing problem. Is it always recoverable, meaning there is no crash and everything will work again once the library finds the correct terminal size?
ncurses
asked Dec 18 at 12:28
Cyker
1,36121429
The doupdate function in ncurses will try to update screen size if necessary:
ncurses/tty/tty_update.c:
if ((SP_PARM->_endwin == ewSuspend)
|| _nc_handle_sigwinch(SP_PARM)) {
/*
* This is a transparent extension: XSI does not address it,
* and applications need not know that ncurses can do it.
*
* Check if the terminal size has changed while curses was off
* (this can happen in an xterm, for example), and resize the
* ncurses data structures accordingly.
*/
_nc_update_screensize(SP_PARM);
}
My question is:
What happens if the terminal is resized after this check is done, but before anything is actually written to the terminal? If the function writes to the terminal in its new size but believes in its old size, will it crash the program or cause other undefined behavior?
It seems _nc_flush merely flushes displayed texts and terminal control characters to the output file descriptor. But I still have no idea what is the worst thing that can happen if there is a sizing problem. Is it always recoverable, meaning there is no crash and everything will work again once the library finds the correct terminal size?
ncurses
ncurses
asked Dec 18 at 12:28
Cyker
1,36121429
asked Dec 18 at 12:28
Cyker
1,36121429
edited Dec 18 at 12:56
asked Dec 18 at 12:28
Cyker
1,36121429
asked Dec 18 at 12:28
Cyker
1,36121429
asked Dec 18 at 12:28
Cyker
1,36121429
1,36121429
The worst (and most likely) thing that can happen is that the display will be messed up. Most character cell programs have a keyboard shortcut for redrawing the screen, usually Ctrl-L. Stuff can always mess up a terminal display, so it is polite to give the user a way to request a complete repainting.
– AlexP
Dec 18 at 13:50
add a comment |
The worst (and most likely) thing that can happen is that the display will be messed up. Most character cell programs have a keyboard shortcut for redrawing the screen, usually Ctrl-L. Stuff can always mess up a terminal display, so it is polite to give the user a way to request a complete repainting.
– AlexP
Dec 18 at 13:50
The worst (and most likely) thing that can happen is that the display will be messed up. Most character cell programs have a keyboard shortcut for redrawing the screen, usually Ctrl-L. Stuff can always mess up a terminal display, so it is polite to give the user a way to request a complete repainting.
– AlexP
Dec 18 at 13:50
The worst (and most likely) thing that can happen is that the display will be messed up. Most character cell programs have a keyboard shortcut for redrawing the screen, usually Ctrl-L. Stuff can always mess up a terminal display, so it is polite to give the user a way to request a complete repainting.
– AlexP
Dec 18 at 13:50
add a comment |
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The worst (and most likely) thing that can happen is that the display will be messed up. Most character cell programs have a keyboard shortcut for redrawing the screen, usually Ctrl-L. Stuff can always mess up a terminal display, so it is polite to give the user a way to request a complete repainting.
– AlexP
Dec 18 at 13:50