bin/56147: FreeBSD/NetBSD /bin/sh mishandles positional parameters in "case"

[Paul Jarc]

>Number:         56147
>Category:       bin
>Synopsis:       FreeBSD/NetBSD /bin/sh mishandles positional parameters in "case"
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Fri Aug 29 10:30:16 PDT 2003
>Closed-Date:
>Last-Modified:
>Originator:     Paul Jarc
>Release:        FreeBSD 4.8-STABLE i386
>Organization:
>Environment:
System: FreeBSD datasink.webmonster.de 4.8-STABLE FreeBSD 4.8-STABLE #5: Wed Aug 6 10:27:33 CEST 2003 root at datasink.webmonster.de:/m/ad0s1e/build/obj/m/ad0s1e/build/src/sys/DATASINKv2 i386


	
>Description:
In /bin/sh "case" patterns, wildcards are supposed to be interpreted as
literal characters if they are quoted or are the result of an expansion.
However, if they appear in the expansion of a positional parameter, they
are interpreted as wildcards.  This can cause scripts to fail silently
and mysteriously.
>How-To-Repeat:
$ sh -c 'set "*"; case x in "$1") echo oops;; esac'
oops
>Fix:
As a workaround, you can assign the value of the positional parameter to
a named parameter, and expand that named parameter in the "case" pattern:
$ sh -c 'set "*"; v=$1; case x in "$v") echo oops;; esac'
>Release-Note:
>Audit-Trail:
>Unformatted: