Re^3: printing enviroment vars from regex

Replies are listed 'Best First'.
Re^4: printing enviroment vars from regex by Aristotle (Chancellor) on Aug 01, 2004 at 19:54 UTC
His version will do nested replacements, eg if `$FOO` expands to the text `$BAR`, then that will in turn be expanded as well. I don't know if that's particularly desirable, though. Makeshifts last the longest.	[reply]
Re^5: printing enviroment vars from regex by Limbic~Region (Chancellor) on Aug 01, 2004 at 20:02 UTC
Aristotle, BUU and I discussed this over in #perl independent of these posts. I understand what his version is doing but I think that is the "wrong" thing to do. `$ FOO="asdf" $ BAR="$FOO you" $ echo $BAR asdf you $ FOO=123 $ echo $BAR asdf you` [download] There is only one level of expansion in environmental variables so I would assume that is what is intended for this script. I did make the caveat that it was fragile with regards to the assumptions I made and that it would have to be modified accordingly. Cheers - L~R	[reply] [d/l]
Re^6: printing enviroment vars from regex by Aristotle (Chancellor) on Aug 01, 2004 at 20:15 UTC
I think it is a bad idea as well. What happens if `FOO='$BAR'` and `BAR='$FOO'`, f.ex? How do you include a literal `$` character in the value of a variable without breaking anything? There are just too many unpredictables. If there's only a single level of replacement, none of these things becomes an issue. Of course, indirection becomes impossible, but that should be implemented properly at the top level, with a well-defined syntax; at that point you are on your way to a full-fledged templating system or even a complete language. Makeshifts last the longest.	[reply]