[net.bugs] csh: bus error msgs to stdout

mcdaniel@uicsrd.CSRD.UIUC.EDU (07/22/86)

Subject: csh can send bus error messages to stdout
Index:	bin/csh 4.2BSD

Description:

	If a program called from a shell script has a bus error, the
	message is sent to the script's standard output.  This behavior
	seems counterintuitive.  (I had redirected standard output, and
	kept wondering "Where is that core file coming from?".)

	This occurs under BSD 4.2; I don't know about any other csh
	versions.

Repeat-By:
	Script started on Mon Jul 21 17:31:25 1986 [with annotations]
	% cat > t.c
	main() { char *t = 0; *t = 999; }
		[this provokes a bus error on most machines, VAXen
		included.  You might have to provoke it some other
		way.]
	^D
	% cc t.c
	% a.out > /dev/null
	Bus error (core dumped)			[as expected]
	% cat > t.csh
	#! /bin/csh -f
	a.out
	^D
	% chmod a+x t.csh
	% t.csh
	Bus error (core dumped)			[as expected]
	% rm core
	% t.csh > file				[no reply]
	% ls
	a.out		file		t.csh
	core		t.c		typescript
						[core file silently appears]
	% cat -n file
	     1	Bus error (core dumped)		[message went into file]
	% exit
	% 
	script done on Mon Jul 21 17:34:43 1986