alto, a music organizer
alto is a program built for audio management. It's purpose is to provide the user the means to create a path construct to move individual audio files to a select path while being provided with the metadata of the file through variables.
Installing
Simply grab a binary from Releases, if it is available. Otherwise go to building to learn how to build alto from source.
Building
You will need Go, Git, and a working internet connection so dependencies in go.mod can be installed.
$ git clone https://github.com/ItsLychee/alto
$ cd alto
$ go build ./cmd/alto
$ ./alto -help
# ...
Path constructs
You may be a bit confused about what the -format argument does, which is understandable. This section is dedicated to teach you on how you can use alto to its fullest to achieve the organization meant for you.
What is a path construct?
A path construct, as it implies, is a result of alto's processing of the -format string with the current file's metadata being used as reference. So when this manual brings up stuff like "omitting from the path construct" it simply means that X value won't be in the final result.
Examples
$ alto -format "{%artist%|unknown artist}/{%album%/}{%title%|%filename%}" -source source -destination destination
# Possible outcomes
Artist/Album/Title.flac # alto automatically appends the file extension if it isn't present in the path construct
Artist/Album/Filename.flac
Artist/Title.flac
Artist/Filename.flac
unknown artist/Album/Title.flac
unknown artist/Album/Filename.flac
unknown artist/Title.flac
unknown artist/Filename.flac
# Alto does the following
# it checks if %artist% exists, if it doesn't then it'll return unknown artist
# Adds "/" after the first group (which is the contents wrapped with the curly braces)
# Returns %album%/ IF the variable %album% is not empty/nonexistent, otherwise it will return nothing
# Returns %title% IF the variable is not empty/nonexsitent, otherwise it will return %filename%, which will always contains a value
Variables
As you may have guessed, %filename% is a variable. Proper variables must have ASCII-only identifiers wrapped around with %, so while %name% is valid, %こんにちは% is not, although this requirement may change in the future.
List of default variables
You are provided with variables representing metadata, metadatic variables are just pipelines to the methods in dhowden's tag metadata interface, and alto will be kept updated to the latest and stable release.
%title%%artist%%album%%albumartist%%genre%%composer%%year%%tracknumber%%tracktotal%%discnumber%%disctotal%%comment%%format%%filetype%%filename%this variable is not handled bytag, but it's just a variable of the name of the current file
The variable names should be self-explantory, you can refer the link above to get a grasp of what each variable does based on the name of it.
Groups
Groups are a collection of fields which are separated by |, and enwrapped by { and }. A group's job is to start on the first field and see if it has a value, if it does not it will keep iterating over the list of fields until it finds a non-nil field. If it does not find a viable field, it will simply just be omitted from the path construct
Field
A field is a collection of string literals and variables. Unlike the outside of a group where only string literals and groups are parsed, variables are also parsed. So %variable% foobar in a field would be represented Variable StringLiteral in a field, but outside one it would be StringLiteral.
Separators
Separators are similar to logical ORs, which if either value is true, then return true, otherwise return false. Instead of returning a boolean, alto returns the evaluated field.
