Path: utzoo!utgpu!jarvis.csri.toronto.edu!clyde.concordia.ca!uunet!virtech!cpcahil
From: cpcahil@virtech.uucp (Conor P. Cahill)
Newsgroups: comp.lang.c
Subject: Re: how to write () a constant?
Keywords: how to, write(), constant
Message-ID: <1990Jan8.113957.3778@virtech.uucp>
Date: 8 Jan 90 11:39:57 GMT
References: <10883@attctc.Dallas.TX.US>
Distribution: na
Organization: Virtual Technologies Inc.
Lines: 29

In article <10883@attctc.Dallas.TX.US>, bobc@attctc.Dallas.TX.US (Bob Calbridge) writes:
> A quick question if you please,  Suppose you want to write a binary constant
> to a file.  Would the following code be valid?
> 
> 	write(handle, (int *) '0x01', sizeof(int))

No.  What this code would do is either core dump with a memory fault or write out
the sizeof(int) bytes starting at location 0x30783031 or location 0 depending 
upon how the compiler interpreted '0x01' but anyway, the value at this location
would probably not be a 1.

If you wanted to write out a 1, you would have to do something like:

	write(handle (char *) &0x01, sizeof(int))

But this is illegal since you cannot use & on a constant.  So what you have to
do is:

	intvar = 0x01;
	write(handle, (char *) &intvar, sizeof(int))




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