# makedat

## Name

makedat -- create GDBM/DB files for maildrop

## Synopsis

makedat {-src=`textfile`} {-tmp=`tmpfile`} {-file=`gdbmfile`} [-cidr]

## DESCRIPTION

The gdbm family of functions in maildrop provides access to GDBM/DB databases - simple database files. The gdbm family of functions provide a way of quickly storing and looking up key/data pairs.

You can use any program to create GDBM/DB database files. makedat is a quick utility to create GDBM or DB files from plain text files.

The system administrator selects whether maildrop uses GDBM or DB database files and whether makedat creates GDBM or DB database files as well.

The makedat command may not be available to you. GDBM/DB support in maildrop is optional, and the system administrator may choose not to install GDBM/DB support and the makedat command.

To see whether GDBM or DB support is being used, run the command "maildrop -v".

The `textfile` argument to makedat is a plain text file containing key/value pairs. Each line in the text file contains a key value, followed by a tab and a data value. The data value may be omitted, which defaults to "1". For example, the following three lines:

    example.com

    domain.com<tab>ok

    foo.domain.com<tab>bad

Three key/value pairs are created: example.com, value "1"; domain.com, value "ok", and "foo.domain.com", value "bad".

Empty lines in `textfile`, and lines starting with the # character, are ignored.

`textfile` can be "-", in which case standard input is used.

`gdbmfile` is the GDBM/DB file to create. If this file exists, its existing contents are replaced.

`tmpfile` is a name of a temporary file in the same directory as `gdbmfile`. `tmpfile` is used by makedat to create the GDBM file, then `tmpfile` is renamed to `gdbmfile`.

This approach foregoes any need for locking in order to be able to dynamically update GDBM/DB files used by maildrop's gdbm functions. However, makedat does not use any locks on `tmpfile`, so multiple instances of makedat using the same `tmpfile` are prohibited.

The `-cidr` flag specifies that the key is an IP netblock in CIDR notation. This flag requires the `Net::CIDR` Perl module to be installed separately. Download Net::CIDR from http://www.cpan.org.

## BUGS

There are historical reasons why database functions in maildrop are called gdbm functions. The initial implementation used GDBM functions exclusively. The ability to use the DB library instead of the GDBM library has been added later.

## EXAMPLE

    makedat blacklist /etc/mail/blacklist.tmp /etc/mail/blacklist.dat

Takes `blacklist`, and creates `/etc/mail/blacklist.dat`, using `/etc/mail/blacklist.tmp` as a temporary file.

## SEE ALSO

maildrop(1), maildropgdbm(5).