The
-u switch causes makemap to
dump the contents (key and data pairs) of an existing database. The
database must exist and be readable for it to be dumped. If you
attempt to dump a database for which you lack read access, you will
get this message:
% makemap -u hash /etc/mail/privatedata
makemap: error opening type hash map /etc/mail/privatedata: Permission denied
You also must specify a type for the map that matches the type
specified when it was made. If you mismatch, you will get an error
such as this:
% makemap -u btree /etc/mail/access
makemap: error creating type btree map access: Invalid argument
If all goes well, the contents of the database will be printed to
your standard output. Each datum will be separated from its key by a
single tab character. Note that the order in which they print will
not necessarily match the order in which they appeared in the
original source text file.
