How do people use environment variables with powershell? I often want to do `FOO=bar ./program`, but this doesn't seem to be supported. I googled briefly, but there weren't many satisfactory answers.
It's equivalent of `export FOO='bar'; ./program` , which is not same as `FOO='bar' ./program`, which, in turn, is equivalent to `OLD_FOO="$FOO"; export FOO='bar'; ./program; export FOO="$OLD_FOO";` .
