How to unpack pkg file from OSX 10.10 and higher

问题

I tried to extract Essentials.pkg from OS X 10.10 following by solution from this answer. But have no success.

I get error gunzip: unknown compression format if i try to extract with cmd: cat Payload | gunzip -dc |cpio -i

I get error: tar: Unrecognized archive format if i try to extract with cmd: tar xzvf Payload Could anyone suggest any solution?

来源：https://stackoverflow.com/questions/34989912/how-to-unpack-pkg-file-from-osx-10-10-and-higher