Subject: bin/242: ps loops when writing to a pipe
To: None <gnats-admin>
From: Bob Kemp <rsk@allegory.demon.co.uk>
List: netbsd-bugs
Date: 05/03/1994 16:05:02
>Number:         242
>Category:       bin
>Synopsis:       ps loops when writing to a pipe
>Confidential:   yes
>Severity:       non-critical
>Priority:       medium
>Responsible:    gnats-admin (Utility Bug People)
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue May  3 16:05:01 1994
>Originator:     Bob Kemp
>Organization:
Home Internet node
Robert Kemp		rsk@allegory.demon.co.uk	Phone: +44 489 581 800
>Release:        -current 05mar94		<<< NB: OLD SYSTEM
>Environment:
	
System: NetBSD allegory 0.9a ALLEGORY#0 i386


>Description:
	FIRST NOTE that I'm using an old version of -current, so it may
	have already been fixed.  I don't have access to a recent version
	and it seems too unstable for me to upgrade at the moment.

	The symptom is that ps occasionally loops when writing to a pipe.
	It doesn't seem to manifest itself when writing to a file (say).

	The shell commands below produce about two looping "ps" commands
	per run.  Ignore the broken pipe error messages. That stuff is
	irrelevant, I just added the $f arg to show the values for which
	it failed.

>How-To-Repeat:

	#!/bin/csh -fx

	foreach f ( {1,2,3,4,5,6,7,8,9,0}{1,2,3,4,5,6,7,8,9,0} )
		ps ax | cat - | echo $f > /dev/null &
		echo $f
	end

	jobs -l
	wait


>Fix:

>Audit-Trail:
>Unformatted:


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