Unpack Mac Packages in Bash

alias unpkg='_(){ if [[ ! $# -eq 1 ]] || [[ ! -f "${1}" ]]; then echo "Usage: unpkg <~file~.pkg>"; else 7z x "${1}"; for a in *.pkg; do if [[ -d "$a" ]]; then cd "$a"; cat Payload | gunzip -dc |cpio -i; cd -; fi; done; fi; }; _'

This alias is not recursive, and will only process one level of pkg's if further pkg files exist you will have to re-run this alias on them as you find them, requires 7z (apt-get install p7zip-full).

Its also recommended to create a new directory and copy the pkg file into it before running, especially when you don't know what may be inside and it makes it easier to see what was extracted.