CDPATH environment variable causes bin scripts to fail.

Most of the scripts in bin/* assume that cd produces no output. But when using bash (and some other shells) cd will output the destination directory if the CDPATH environment variable is set. CDPATH is very useful, and it's unfortunate to have to unset it to use Hadoop.

The offending line (in start-all.sh, though most of the scripts exhibit the problem) is:

bin=`cd "$bin"; pwd`

Adding this to the top of each affected script will fix the problem:

unset CDPATH