[comp.lang.c] A question about stdin, stdout and stderr

oae@intrin.UUCP (02/20/87)

I have a problem. I generated a program with lex on ULTRIX and moved
that program to VMS. On VMS I got an error message from the next line:

FILE *yyin = {stdin}, *yyout = {stdout};
	
The VMS's C compiler didn't translate these initializations, because
stdin and stdout are variables on VMS. On ULTRIX they are constants.
Then I examined The Father, The Son and The Holy Ghost and found
the following:

1. The K&R, p 153, says:

	"The file pointers stdin and stdout are pre-defined in the I/O
	 library as the standard input and standard output; they may be
	 used anywhere an object of type FILE * can be. The are constants,
	 however, not variables, so don't try to assign to them."
	 
	 
2. Harbison, Steele: A C Reference Manual, p 316, says:

	"11.5.32 stdin
	 ..., the external variable stdin will contain a stream that..."

	"11.5.33 stdout
	 ..., the external variable stdout will contain a stream that..."

3. As for I know the draft ANSI C standard says that stdin, stdout and
   stderr are expressions.

So, are they constants, variables or expression? I think that The K&R
has the only right definition for stdin, stdout and stderr, the others
are wrong.


Olavi Eerola			oae@intrin.uucp
Intrinsic Oy
Aleksis Kiven katu 11 C
SF-33100 Tampere, Finland	+358-31-132800