### 4.7.4 Other sources of information

The Internals Reference documentation contains a lot of information about LilyPond, but even more information can be gathered by looking at the internal LilyPond files. To explore these, you must first find the directory appropriate to your system. The location of this directory depends (a) on whether you obtained LilyPond by downloading a precompiled binary from lilypond.org or whether you installed it from a package manager (i.e. distributed with GNU/Linux, or installed under fink or cygwin) or compiled it from source, and (b) on which operating system it is being used:

#### Downloaded from lilypond.org

- GNU/Linux

  Navigate to

  >     ‘INSTALLDIR/lilypond/usr/share/lilypond/current/’

- MacOS X

  Navigate to

  >     ‘INSTALLDIR/LilyPond.app/Contents/Resources/share/lilypond/current/’

  by either `cd`-ing into this directory from the Terminal, or control-clicking on the LilyPond application and selecting ‘Show Package Contents’.

- Windows

  Using Windows Explorer, navigate to

  >     ‘INSTALLDIR/LilyPond/usr/share/lilypond/current/’

#### Installed from a package manager or compiled from source

Navigate to ‘`PREFIX/share/lilypond/X.Y.Z/`’, where PREFIX is set by your package manager or `configure` script, and X.Y.Z is the LilyPond version number.

Within this directory the two interesting subdirectories are

- ‘`ly/`’ - contains files in LilyPond format
- ‘`scm/`’ - contains files in Scheme format

Let’s begin by looking at some files in ‘`ly/`’. Open ‘`ly/property-init.ly`’ in a text editor. The one you normally use for `.ly` files will be fine. This file contains the definitions of all the standard LilyPond predefined commands, such as `\stemUp` and `\slurDotted`. You will see that these are nothing more than definitions of variables containing one or a group of `\override` commands. For example, `/tieDotted` is defined to be:

>     tieDotted = {
>       \override Tie.dash-period = #0.75
>       \override Tie.dash-fraction = #0.1
>     }

If you do not like the default values these predefined commands can be redefined easily, just like any other variable, at the head of your input file.

The following are the most useful files to be found in ‘`ly/`’:

Filename | Contents
--- | ---
‘`ly/engraver-init.ly`’ | Definitions of engraver Contexts
‘`ly/paper-defaults-init.ly`’ | Specifications of paper-related defaults
‘`ly/performer-init.ly`’ | Definitions of performer Contexts
‘`ly/property-init.ly`’ | Definitions of all common predefined commands
‘`ly/spanner-init.ly`’ | Definitions of spanner-related predefined commands

Other settings (such as the definitions of markup commands) are stored as ‘`.scm`’ (Scheme) files. The Scheme programming language is used to provide a programmable interface into LilyPond internal operation. Further explanation of these files is currently outside the scope of this manual, as a knowledge of the Scheme language is required. Users should be warned that a substantial amount of technical knowledge or time is required to understand Scheme and these files (see Scheme tutorial).

If you have this knowledge, the Scheme files which may be of interest are:

Filename | Contents
--- | ---
‘`scm/auto-beam.scm`’ | Sub-beaming defaults
‘`scm/define-grobs.scm`’ | Default settings for grob properties
‘`scm/define-markup-commands.scm`’ | Specify all markup commands
‘`scm/midi.scm`’ | Default settings for MIDI output
‘`scm/output-lib.scm`’ | Settings that affect appearance of frets, colors, accidentals, bar lines, etc
‘`scm/parser-clef.scm`’ | Definitions of supported clefs
‘`scm/script.scm`’ | Default settings for articulations

其他语言：česky, deutsch, español, français, italiano, 日本語, nederlands。
About automatic language selection.

#### LilyPond — Learning Manual v2.18.2 (稳定分支).