Answer by Alek for How to obtain the absolute path of a file via Shell (BASH/ZSH/SH)?

This is not an answer to the question, but for those who does scripting:

echo `cd "$1" 2>/dev/null&&pwd||(cd "$(dirname "$1")";pwd|sed "s|/*\$|/${1##*/}|")`

it handles / .. ./ etc correctly. I also seems to work on OSX