Stewart Stremler wrote:
> begin quoting John H. Robinson, IV as of Thu, Mar 03, 2005 at 12:34:58AM
> -0800:
> [snip]
> > # TODO: if there is no env var supplied, default to using $PATH
> > #i cannot seem to do that in pure sh. if i look in the output of env,
> > #yes. if i use bash or zsh, yes. pure sh? not that i have found, yet
>
> How about a simple, short example that demonstrates exactly the
> behavior that causes the problem?
read first option
if option is an env. var,
then use it
else
use PATH as a default
in bash:
var=$1
VAR=${!var-ThisVarNotSet}
if [ .$VAR = .ThisVarNotSet ];
var=PATH
VAR=${!var}
fi
in zsh:
var=$1
VAR=${(P)var-ThisVarNotSet}
if [ .$VAR = .ThisVarNotSet ];
var=PATH
VAR=${(P)var}
fi
In sh, I could use env and grep. I'd prefer to avoid that.
var=$1
if [ ! env | grep \^$var= >/dev/null 2>&1 ];
var=PATH
fi
VAR=`eval echo \\$$var`
Mostly untested.
-john
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