psql: present working directory

Dear hackers,

Is there any interest in having a backslash command to psql that
prints the current working directory?  This would nicely complement
the functionality offered by \cd.

The command could be either a new command like \pwd, or simply make
this the behaviour of \cd with no argument; much the same way that \f
shows the current field separator when invoked without an argument.

Example:

postgres=> \cd /foo/bar/baz
postgres=> \cd
Working directory is "/foo/bar/baz".

Clearly it's a minor convenience feature, but I know I would use it,
and I don't see a downside.  Currently \cd with no argument does
nothing at all.

Happy to provide a patch in the absence of any objections.

Regards,
BJ