os: what not to do when using environment variables...
let's say you want to set a value to foo. so, you do something like this:
(you probably already see the mistake i just made.) so, now you want to retrieve the variable to use somewhere. you try to get it back by using this:
so alright, it looks like it took. why doesn't it come back with the first echo command? notice the spaces in the variable? try echoing %foo %.
even the value returned has a space. apparently, it is quite literal about those spaces. :) clear the value and try again (don't forget the space). now it works fine:
C:\>set foo = geniusboy
(you probably already see the mistake i just made.) so, now you want to retrieve the variable to use somewhere. you try to get it back by using this:
C:\>echo %foo% %foo%
instead of getting back geniusboy, you get back %foo%. hmmm. where did it go? now you run this command just to list all the environment variables that start with f:
C:\>set f foo = geniusboy FP_NO_HOST_CHECK=NO
so alright, it looks like it took. why doesn't it come back with the first echo command? notice the spaces in the variable? try echoing %foo %.
C:\>echo %foo % geniusboy
even the value returned has a space. apparently, it is quite literal about those spaces. :) clear the value and try again (don't forget the space). now it works fine:
C:\>set foo = C:\>set foo=geniusboy C:\>echo %foo% geniusboy
Comments
Post a Comment