#205 breaks on OS X

[ogr3]

On my OS X installation (10.11.1) test -v does not work at all, see #205.

It works on Cygwin and Ubuntu but not OS X. I guess the /bin/test on OS X does not support -v.

[ogr3]

test -v was added in bash 4.2 (but still this test fails on OS X with bash 4.3 from homebrew):

http://stackoverflow.com/questions/3601515/how-to-check-if-a-variable-is-set-in-bash

We should use a more backwards compatible test than that IMHO,

maybe the suggested pattern

if [ -z ${var+x} ]; then echo "var is unset"; else echo "var is set to '$var'"; fi

As far as I can see that handles empty strings.

[ogr3]

Did a PR implementing this in #208

[ogr3]

PR merged. closing.