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From: mark@ems.MN.ORG (Mark H. Colburn)
Newsgroups: comp.sources.bugs
Subject: Re: Compress  error message -n comp.sources.bugs -f wjc@ho5cad.ATT.COM
Message-ID: <667@ems.MN.ORG>
Date: Mon, 31-Aug-87 14:36:21 EDT
Article-I.D.: ems.667
Posted: Mon Aug 31 14:36:21 1987
Date-Received: Fri, 4-Sep-87 06:26:32 EDT
References: <339@cbstr1.att.com> <209@ho7cad.ATT.COM>
Reply-To: mark@ems.UUCP (Mark H. Colburn)
Organization: EMS/McGraw-Hill, Eden Pairie, MN
Lines: 53

In article <209@ho7cad.ATT.COM> nuucp@ho7cad.ATT.COM (UUCP) writes:
>In article <339@cbstr1.att.com> Karl.Kleinpaste@cbstr1.att.com writes:
>>>  This month's "Worst Error Message of the Month Award" goes
>>>  unconditionally to compress 4.0.
>>>	   Not a typewriter
>>>  Well, duh!  That's right, it's NOT a typewriter.
>Well, I agree.  This  is pretty funny.   But don't blame compress.   A
>lot  of  programs give you  this.   Seems to be  what  you get on some
>machines when you  call "perror()" when  there ain't been no error (of
>its genre) [or  maybe when the error number  is bigger than the secret
>message array].

	We got this problem from Unipress EMACS as well.  The problem is that
the program is calling ioctl and attempting to get or set terminal 
parameters for the input or output file.  It would appear that the programs 
are trying to be generic by getting or setting terminal parameters on any file 
that they do i/o from.  However, In the case where the input or output file is 
not a terminal, ioctl will return the above error.

	Specifically, the error will be generated if you attempt to read or
write the terminal settings when the target file is not a terminal.  For 
example (this code is for System V.2, Berkley may be different):

	struct termio 	cb;
	int		fd;

	if(ioctl(fd, TCGETA, &cb) == -1) {
	  perror(NULL); /* die with a "Not a typewriter" error */
	} else {
	  ... do some stuff ...
	}

	This is easily worked around (if you have source to the package which 
is causing you a problem) by adding a isatty() before the offending ioctl..

	struct termio 	cb;
	int		fd;

	if (isatty(fd) {
	   if(ioctl(fd, TCGETA, &cb) == -1) {
	      perror(NULL); /* die with a "Not a typewriter" error */
	   } else {
	      /* ... do some stuff ... */
	   }
	} else {
	   /* handle a regular file (probably do nothing) */
	}

	Hope that this helps!

-- 
Mark H. Colburn    DOMAIN: mark@ems.MN.ORG 
EMS/McGraw-Hill      UUCP: ihnp4!meccts!ems!mark      AT&T: (612) 829-8200