Quick and Easy printf() question

man curses

I like pie.

You can''t do it with printf (the effect isn''t as "simple" as you think, btw). For Unix/Linux, look for [n]curses.

void twiddle()
{
static int index = 0;
const char twiddles[] = "|/-\";

printf( "%c\b", twiddles[index++] );
index %= sizeof( twiddles ) - 1;
}

"Most people think, great God will come from the sky, take away everything, and make everybody feel high" - Bob Marley

@Paradigm Shifter:
Your program will eventually fill the screen with a looping sequence of characters, which is quite different from the OP''s desired effect of animating the sequence of characters in-place.

quote:

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Original post by Oluseyi
@Paradigm Shifter:
Your program will eventually fill the screen with a looping sequence of characters, which is quite different from the OP''s desired effect of animating the sequence of characters in-place.

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Not if \b is the escape code for a backspace it won''t.

printf("%c\b");

Umm, that erases the character right after you print it, which effectively does nothing.

You want printf("\b%c"); to erase the previous char and put the new one in its place. Don't forget to initialize the loop by writing the first character without the backspace though.

Not to mention buffering also, which means you should call fflush(stdout); after each print.

I tried it on Redhat 6.2, and it works ok, except you need to come up with a way to interrupt the loop when a key is pressed. Don't forget a delay between prints also.

I wouldn't suggest it as a portable solution though. If it works on your machine, fine, but don't expect it to work in all situations.

[edited by - cgoat on February 4, 2004 12:54:33 PM]

quote:

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Original post by Paradigm Shifter
Not if \b is the escape code for a backspace it won''t.

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You''re right, but it''s not portable. I forgot the OP wanted a Red Hat solution, which yours is. On Windows, you get a non-printing character for \b.