cc: ksh93-integration-discuss at opensolaris.org pkchris at
users.sourceforge.ne don.cragun at sun.com
Subject: Re: Re: [shell-discuss] [ksh93-integration-discuss] CR 6791838 Created
P3 shell/korn93 *ksh93* unset of a variablewhich is not set should return 0
--------
> [[ ${x+y} ]] would check if a variable exists? Which function does y in
> ${x+y} have?
>
> Chris
> --
>
y can be anything other than the null string.
[[ y ]] just checks whether y is the empty string or not.
Therefore this will either be
[[ ]] if x is unset -> exit status 1
or
[[ y ]] if x is set -> exit status 0.
David Korn
dgk at research.att.com
