Re: [OT] C help plz..

[Matthew Dalton <matthewd@research.canon.com.au>]

Sorry... I automatically made a link between binary data and hexadecimal
data...

You could shift 8 bits of the unsigned long into a unsigned char one at
a time, and print that character with a %c in the printf, or use
putchar() or something.

eg:
	unsigned long l = 0x38c9616e;
	unsigned char c;
	:
	:
	c = (l & 0xFF000000) >> 24;
	putchar(c);
	c = (l & 0x00FF0000) >> 16;
	putchar(c);
	c = (l & 0x0000FF00) >> 8;
	putchar(c);
	c = l & 0x000000FF;
	putchar(c);

Is this what you were looking for? I suppose you wanted something
simple, ie using printf... I'm not sure about that.

	printf
	(
		"%c%c%c%c",
		(l & 0xFF000000) >> 24,
		(l & 0x00FF0000) >> 16,
		(l & 0x0000FF00) >> 8,
		l & 0x000000FF
	);
this might be as close as you can get.

Shao Zhang wrote:
> 
> But isn't %[Xx] just prints out as Hexdecimal?
> I just tried, and it prints out something like: 38c9616e
> 
> which consumes 8 bytes in a file. Given that unsigned long is 32 bits,
> I want to use exactly 4 byte to represent it in order to save some
> space.
> 
> Thanks.
> 
> Shao.
> 
> Matthew Dalton [matthewd@research.canon.com.au] wrote:
> > Try using %X or %x instead of %ld
> >
> > Shao Zhang wrote:
> > >
> > > Hi,
> > >         If I have an unsigned long int, instead printing out its values
> > >         in string using printf("%ld\n", my_var),
> > >
> > >         I would like to print it out as a 4-byte binary data. Is there
> > >         any easy way to do this in C.
> > >
> > >         Thanks.
> > > Shao.
> > >
> > > --
> > > ____________________________________________________________________________
> > > Shao Zhang - Running Debian 2.1  ___ _               _____
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> > > Sydney, Australia               |___/_||_\__,_\___/ /___|_||_\__,_|_||_\__, |
> > > Email: shao@cia.com.au                                                  |___/
> > > _____________________________________________________________________________
> > >
> > > --
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> >
> 
> --
> ____________________________________________________________________________
> Shao Zhang - Running Debian 2.1  ___ _               _____
> Department of Communications    / __| |_  __ _ ___  |_  / |_  __ _ _ _  __ _
> University of New South Wales   \__ \ ' \/ _` / _ \  / /| ' \/ _` | ' \/ _` |
> Sydney, Australia               |___/_||_\__,_\___/ /___|_||_\__,_|_||_\__, |
> Email: shao@cia.com.au                                                  |___/
> _____________________________________________________________________________