Re: Cross Platform clear terminal
Glen Barber wrote:
What I intended (and it works in UNIX) is, before anything else, to clear
the console. For this, I used:
system("clear");
however, I have read this is a "crude hack".
This creates a shell and executes 'clear' in that shell's context. Whether
this 'clear' makes any sense in that shell's context is up to the shell and
possibly the installed programs. It might as well clear your harddisk or
make the window translucent, as far as C++ is concerned.
It does, for the intent of my test app, compile and execute as expected;
but in Win32, obviously "clear" isn't a command -- "cls" is.
Well, the mechanism is the same but as already mentioned, the shell is a
different one thus the different command or program needed.
What you can do is define the argument to system() via an environment
variable or configuration option. If it doesn't exist you fall back to
doing nothing. That allows you to customise the behaviour of your program
to the used shell without recompiling the program itself, while still
hopefully getting readable output without it.
I am aware I need the application to differentiate between what platform
it is running, but I can't seem to figure out (or find via Google) what I
might be missing. Any pointers would be greatly appreciated.
There is no universal way to do what you want. E.g. if you attach the
program to a line printer, you simply can't erase lines already written.
What you can do is print a few newlines to make a visual separation to the
current content, this is also portable. For anything further, you need
add-on libraries that allow you to control a terminal.
The typically-used interface for terminal control is called 'curses', which
comes in different implementations for most desktop OSs. This then also
allows you to do things like positioning the cursor or create ASCII-art
windows like e.g. Norton Commander does. However, even though this API has
been widely ported, it still relies on features that are not guaranteed to
be present and thus are not 100% portable.
Uli
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