Environment variable substitution and error handling
Environment variable substitution and error handling

It makes way more sense now. The panic handling is fixed.

A nice side effect: the first \n ends substitution UNLESS it's in a '' pair.

I think this is sane: it makes errors like
echo $/bin/date

a lot more sane. You really don't want 2M of binary in the command line.

Signed-off-by: Ronald G. Minnich <f569d0af9a3481c4007b95c7180d6c41009f2513@gmail.com>

rminnich/u-root,hugelgupf/u-root,rminnich/u-root,rminnich/u-root,hugelgupf/u-root,GanShun/u-root,GanShun/u-root,hugelgupf/u-root,GanShun/u-root,u-root/u-root,rminnich/u-root,u-root/u-root,hugelgupf/u-root,u-root/u-root