Porcelain driver that offers basic functionality for interacting with external programs.

Users are not supposed to call functions in this module directly. Use functions in Porcelain instead.

This driver has two major limitations compared to Porcelain.Driver.Goon:

• the exec function does not work with programs that read all input until EOF before producing any output. Such programs will hang since Erlang ports don’t provide any mechanism to indicate the end of input.

  If a program is continuously consuming input and producing output, it could work with the spawn function, but you’ll also have to explicitly close the connection with the external program when you’re done with it.

• sending OS signals to external processes is not supported