======
GETEMX
======

getemx reads the .emx files used by `Emusic
<http://www.emusic.com>`_ and downloads the files they describe. Its
behavior is controlled by the file ~/.emxdownloader, which contains
instructions for file naming, art downloading, etc (see below in
`Invocation`_). It downloads files using either wget, curl, or
Haskell's interface to libcurl (though I would be surprised if anyone
who had libcurl installed didn't also have the curl binary).

Building & Installation
=======================

It should be possible to build and install getemx using `cabal
<http://www.haskell.org/cabal>`_.

Invocation
==========

getemx accepts no options on the command line. Its arguments should
consist simply of .emx files; the simplest way to invoke it is::

   $ getemx *.emx

where the .emx files are in the current directory.

getemx will read a file in your home directory called ".emxdownloader"
which can define options to control its behavior. Options may either
be *boolean* or *string*; the values of boolean options must be one of
"f", "t", "false", or "true" while string options may be any
string. The syntax of the .emxdownloader file is very simple::

   option = value

Any amount of whitespace may occur before or after the "=". The
following are boolean options:

- **replace_underscores**: if true, underscores in the filename will be replaced by spaces. True by default.
- **replace_apostrophe_identity**: if true, the string "``&#039;``" in filenames will be replaced by "``'``". True by default.
- **get_art**: if true, cover art will be downloaded for each album. True by default.

Currently the only string options control the filenames of the
downloaded files. There are two classes here: **dldir** specifies a
directory *relative to which* further processing will take place,
while **dlfmt** and **dlfmt_multidisc** specify how to process
*individual files*. The latter two accept a number of replacement
options:

================== ================
**Format string:** **Replaced by:**
================== ================
``%(a)``           Artist name
``%(A)``           Album name
``%(n)``           Track number
``%(t)``           Track name
``%(D)``           Total number of discs in set
``%(d)``           Number of present disc in set (e.g. 2 out of 4)
``%(l)``           Label
``%(e)``           File extension
``%(g)``           Genre
``%%``             ``%``
================== ================

The defaults for the string options are:

- **dldir**: ``.``
- **dlfmt**: ``%(a)/%(A)/%(a) - %(A) - %(n) - %(t)``
- **dlfmt_multidisc**: ``%(a)/%(A): %(d)/%(a) - %(A): %(d) - %(n) - %(t)``

**dlfmt_multidisc** is used if a track is being downloaded that
belongs to a set with more than one disc; otherwise, **dlfmt** is
used. Note that at present the default for dlfmt_multidisc will
probably do the wrong thing on OS X. Note also that neither of the
default values ends with ``%(e)``: the file extension is supplied
automatically if it is not explicitly specified.

A ~/.emxdownloader file that set every option to its default value
could look like this::

    get_art = t
    replace_underscores = t
    replace_apostrophe_identity = t
    dldir = .
    dlfmt = %(a)/%(A)/%(a) - %(A) - %(n) - %(t)
    dlfmt_multidisc = %(a)/%(A): %(d)/%(a) - %(A): %(d) - %(n) - %(t)

"Could" because one could also write "true" out in full for "t".