Fix for issue 1 breaks on macos

[mattmartini]

The code used to correct issue #1 in env.bash does not work on macos.

Specifically, expr index causes a syntax error. The BSD version, which is the basis for the macos version, of expr does not support length, substr, index,or match.

The second field can be found by taking the $line and deleting everything upto ': '

This can be done like:
pwd=${line#*: }

I will be submitting a pull request to fix this issue.

Note: the first field can me found via:

key=${line%%:*}

This will not be changed in the PR.

Finally, as a side issue tr a-z A-Z should be written tr "[:lower:]" "[:upper:]" to properly capitalize.

[Steve Kemp]

I appreciate the detailed bug-report, and your pull-request looks like it does the right kind of thing.

I'll test it locally today, and if it continues to work for me will merge later this evening.

Thanks again!

[Steve Kemp]

Closed in #3.