It's not that bash is different across platforms (it's not different) -- it's that utils like sed/grep/awk are different because Linux has the GNU variety, wher

It's not that bash is different across platforms (it's not different) -- it's that utils like sed/grep/awk are different because Linux has the GNU variety, whereas Mac has the BSD variety. In practice though, it's not all that hard to make it work across both.