LilyPond Application Usage: 1.2 Command-line usage

## 1.2 Command-line usage

This section contains extra information about using LilyPond on the command-line. This may be desirable to pass extra options to the program. In addition, there are certain extra ‘helper’ programs (such as `midi2ly`) which are only available on the command-line.

By ‘command-line’, we mean the command line in the operating system. Windows users might be more familiar with the terms ‘DOS shell’ or ‘command shell’. MacOS X users might be more familiar with the terms ‘terminal’ or ‘console’. Some additional setup is required for MacOS X users; please see MacOS X.

Describing how to use this part of an operating system is outside the scope of this manual; please consult other documentation on this topic if you are unfamiliar with the command-line.

### Invoking `lilypond`

The `lilypond` executable may be called as follows from the command line.

>     lilypond [option]… file…

When invoked with a filename that has no extension, the ‘`.ly`’ extension is tried first. To read input from stdin, use a dash (`-`) for file.

When ‘`filename.ly`’ is processed it will produce ‘`filename.ps`’ and ‘`filename.pdf`’ as output. Several files can be specified; they will each be processed independently. 1

If ‘`filename.ly`’ contains more than one `\book` block, then the rest of the scores will be output in numbered files, starting with ‘`filename-1.pdf`’. In addition, the value of `output-suffix` will be inserted between the basename and the number. An input file containing

>     #(define output-suffix "violin")
>     \score { … }
>     #(define output-suffix "cello")
>     \score { … }

will output base‘`-violin.pdf`’ and base‘`-cello-1.pdf`’.

#### Standard shell commands

If your shell (i.e. command window) supports normal redirects, then you might find it useful to use the following commands to redirect console output to a file:

- `lilypond file.ly 1>stdout.log` to redirect normal output
- `lilypond file.ly 2>stderr.log` to redirect error messages
- `lilypond file.ly &>all.log` to redirect all output

Consult the documentation for your shell to see if it supports these options, or if the syntax is different. Note that these are shell commands and have nothing to do with lilypond.

### Command line options for `lilypond`

The following options are supported:

`-e,--evaluate=expr`

  Evaluate the Scheme expr before parsing any ‘`.ly`’ files. Multiple `-e` options may be given, they will be evaluated sequentially.

  The expression will be evaluated in the `guile-user` module, so if you want to use definitions in expr, use

  >     lilypond -e '(define-public a 42)'

  on the command-line, and include

  >     #(use-modules (guile-user))

  at the top of the `.ly` file.

`-f,--format=format`

  which formats should be written. Choices for `format` are `ps`, `pdf`, and `png`.

  Example: `lilypond -fpng filename.ly`

`-d,--define-default=var=val`

  This sets the internal program option var to the Scheme value val. If val is not supplied, then #t is used. To switch off an option, `no-` may be prefixed to var, e.g.

  >     -dno-point-and-click

  is the same as

  >     -dpoint-and-click='#f'

  Here are a few interesting options.

  ‘`help`’

    Running `lilypond -dhelp` will print all of the `-d` options available.

  ‘`paper-size`’

    This option sets the default paper-size,

    >     -dpaper-size=\"letter\"

    Note that the string must be enclosed in escaped quotes ( `\"` ).

  ‘`safe`’

    Do not trust the `.ly` input.

    When LilyPond formatting is available through a web server, either the `--safe` or the `--jail` option MUST be passed. The `--safe` option will prevent inline Scheme code from wreaking havoc, for example

    >     #(system "rm -rf /")
    >     {
    >       c4^#(ly:export (ly:gulp-file "/etc/passwd"))
    >     }

    The `-dsafe` option works by evaluating in-line Scheme expressions in a special safe module. This safe module is derived from GUILE ‘`safe-r5rs`’ module, but adds a number of functions of the LilyPond API. These functions are listed in ‘`scm/safe-lily.scm`’.

    In addition, safe mode disallows `\include` directives and disables the use of backslashes in TeX strings.

    In safe mode, it is not possible to import LilyPond variables into Scheme.

    `-dsafe` does not detect resource overuse. It is still possible to make the program hang indefinitely, for example by feeding cyclic data structures into the backend. Therefore, if using LilyPond on a publicly accessible webserver, the process should be limited in both CPU and memory usage.

    The safe mode will prevent many useful LilyPond snippets from being compiled. The `--jail` is a more secure alternative, but requires more work to set up.

  ‘`backend`’

    the output format to use for the back-end. Choices for `format` are

    `ps`

      for PostScript.

      Postscript files include TTF, Type1 and OTF fonts. No subsetting of these fonts is done. When using oriental character sets, this can lead to huge files.

    `eps`

      for encapsulated PostScript. This dumps every page (system) as a separate ‘`EPS`’ file, without fonts, and as one collated ‘`EPS`’ file with all pages (systems) including fonts.

      This mode is used by default by `lilypond-book`.

    `svg`

      for SVG (Scalable Vector Graphics).

      This creates a single SVG file, without embedded fonts, for every page of output. It is recommended to install the Century Schoolbook fonts, included with your LilyPond installation, for optimal rendering. Under UNIX, simply copy these fonts from the LilyPond directory (typically ‘`/usr/share/lilypond/VERSION/fonts/otf/`’) to ‘`~/.fonts/`’. The SVG output should be compatible with any SVG editor or user agent.

    `scm`

      for a dump of the raw, internal Scheme-based drawing commands.

    `null`

      do not output a printed score; has the same effect as `-dno-print-pages`.

    Example: `lilypond -dbackend=svg filename.ly`

  ‘`preview`’

    Generate an output file containing the titles and the first system of music. If `\bookpart` blocks are used, the titles and first system of every `\bookpart` will appear in the output. The `ps`, `eps`, and `svg` backends support this option.

  ‘`print-pages`’

    Generate the full pages, the default. `-dno-print-pages` is useful in combination with `-dpreview`.

`-h,--help`

  Show a summary of usage.

`-H,--header=FIELD`

  Dump a header field to file ‘`BASENAME.FIELD`’.

`--include, -I=directory`

  Add directory to the search path for input files.

  Multiple -I options may be given. The search will start in the first defined directory, and if the file to be included is not found the search will continue in subsequent directories.

`-i,--init=file`

  Set init file to file (default: ‘`init.ly`’).

`-o,--output=FILE or FOLDER`

  Set the default output file to FILE or, if a folder with that name exists, direct the output to FOLDER, taking the file name from the input file. The appropriate suffix will be added (e.g. `.pdf` for pdf) in both cases.

`--ps`

  Generate PostScript.

`--png`

  Generate pictures of each page, in PNG format. This implies `--ps`. The resolution in DPI of the image may be set with

  >     -dresolution=110

`--pdf`

  Generate PDF. This implies `--ps`.

`-j,--jail=user,group,jail,dir`

  Run `lilypond` in a chroot jail.

  The `--jail` option provides a more flexible alternative to `--safe` when LilyPond formatting is available through a web server or whenever LilyPond executes externally provided sources.

  The `--jail` option works by changing the root of `lilypond` to jail just before starting the actual compilation process. The user and group are then changed to match those provided, and the current directory is changed to dir. This setup guarantees that it is not possible (at least in theory) to escape from the jail. Note that for `--jail` to work `lilypond` must be run as root, which is usually accomplished in a safe way using `sudo`.

  Setting up a jail is a slightly delicate matter, as we must be sure that LilyPond is able to find whatever it needs to compile the source inside the jail. A typical setup comprises the following items:

  Setting up a separate filesystem

    A separate filesystem should be created for LilyPond, so that it can be mounted with safe options such as `noexec`, `nodev`, and `nosuid`. In this way, it is impossible to run executables or to write directly to a device from LilyPond. If you do not want to create a separate partition, just create a file of reasonable size and use it to mount a loop device. A separate filesystem also guarantees that LilyPond cannot write more space than it is allowed.

  Setting up a separate user

    A separate user and group (say, `lily`/`lily`) with low privileges should be used to run LilyPond inside the jail. There should be a single directory writable by this user, which should be passed in dir.

  Preparing the jail

    LilyPond needs to read a number of files while running. All these files are to be copied into the jail, under the same path they appear in the real root filesystem. The entire content of the LilyPond installation (e.g., ‘`/usr/share/lilypond`’) should be copied.

    If problems arise, the simplest way to trace them down is to run LilyPond using `strace`, which will allow you to determine which files are missing.

  Running LilyPond

    In a jail mounted with `noexec` it is impossible to execute any external program. Therefore LilyPond must be run with a backend that does not require any such program. As we already mentioned, it must be also run with superuser privileges (which, of course, it will lose immediately), possibly using `sudo`. It is a good idea to limit the number of seconds of CPU time LilyPond can use (e.g., using `ulimit -t`), and, if your operating system supports it, the amount of memory that can be allocated.

`-v,--version`

  Show version information.

`-V,--verbose`

  Be verbose: show full paths of all files read, and give timing information.

`-w,--warranty`

  Show the warranty with which GNU LilyPond comes. (It comes with NO WARRANTY!)

### Environment variables

`lilypond` recognizes the following environment variables:

`LILYPOND_DATADIR`

  This specifies a directory where locale messages and data files will be looked up by default. The directory should contain subdirectories called ‘`ly/`’, ‘`ps/`’, ‘`tex/`’, etc.

`LANG`

  This selects the language for the warning messages.

`LILYPOND_GC_YIELD`

  A variable, as a percentage, that tunes memory management behavior. A higher values means the program uses more memory, a smaller value means more CPU time is used. The default value is `70`.

### LilyPond in chroot jail

Setting up the server to run LilyPond in a chroot jail is a complicated task. The steps are listed below. Examples in the steps are from Ubuntu Linux, and may require the use of `sudo` as appropriate.

- Install the necessary packages: LilyPond, GhostScript, and ImageMagick.
- Create a new user by the name of `lily`:

  >     adduser lily

  This will create a new group for the `lily` user as well, and a home folder, `/home/lily`

- In the home folder of the `lily` user create a file to use as a separate filesystem:

  >     dd if=/dev/zero of=/home/lily/loopfile bs=1k count= 200000

  This example creates a 200MB file for use as the jail filesystem.

- Create a loop device, make a file system and mount it, then create a folder that can be written by the `lily` user:

  >     mkdir /mnt/lilyloop
  >     losetup /dev/loop0 /home/lily/loopfile
  >     mkfs -t ext3 /dev/loop0 200000
  >     mount -t ext3 /dev/loop0 /mnt/lilyloop
  >     mkdir /mnt/lilyloop/lilyhome
  >     chown lily /mnt/lilyloop/lilyhome

- In the configuration of the servers, the JAIL will be `/mnt/lilyloop` and the DIR will be `/lilyhome`.
- Create a big directory tree in the jail by copying the necessary files, as shown in the sample script below.

  You can use `sed` to create the necessary copy commands for a given executable:

  >     for i in "/usr/local/lilypond/usr/bin/lilypond" "/bin/sh" "/usr/bin/;  \
  >       do ldd $i | sed 's/.*=> \/\(.*\/\)\([^(]*\).*/mkdir -p \1 \&\&  \
  >         cp -L \/\1\2 \1\2/' | sed 's/\t\/\(.*\/\)\(.*\) (.*)$/mkdir -p  \
  >           \1 \&\& cp -L \/\1\2 \1\2/' | sed '/.*=>.*/d'; done

### Example script for 32-bit Ubuntu 8.04

>     #!/bin/sh
>     ## defaults set here

>     username=lily
>     home=/home
>     loopdevice=/dev/loop0
>     jaildir=/mnt/lilyloop
>     # the prefix (without the leading slash!)
>     lilyprefix=usr/local
>     # the directory where lilypond is installed on the system
>     lilydir=/$lilyprefix/lilypond/

>     userhome=$home/$username
>     loopfile=$userhome/loopfile
>     adduser $username
>     dd if=/dev/zero of=$loopfile bs=1k count=200000
>     mkdir $jaildir
>     losetup $loopdevice $loopfile
>     mkfs -t ext3 $loopdevice 200000
>     mount -t ext3 $loopdevice $jaildir
>     mkdir $jaildir/lilyhome
>     chown $username $jaildir/lilyhome
>     cd $jaildir

>     mkdir -p bin usr/bin usr/share usr/lib usr/share/fonts $lilyprefix tmp
>     chmod a+w tmp

>     cp -r -L $lilydir $lilyprefix
>     cp -L /bin/sh /bin/rm bin
>     cp -L /usr/bin/convert /usr/bin/gs usr/bin
>     cp -L /usr/share/fonts/truetype usr/share/fonts

>     # Now the library copying magic
>     for i in "$lilydir/usr/bin/lilypond" "$lilydir/usr/bin/guile" "/bin/sh"  \
>       "/bin/rm" "/usr/bin/gs" "/usr/bin/convert"; do ldd $i | sed 's/.*=>  \
>         \/\(.*\/\)\([^(]*\).*/mkdir -p \1 \&\& cp -L \/\1\2 \1\2/' | sed  \
>           's/\t\/\(.*\/\)\(.*\) (.*)$/mkdir -p \1 \&\& cp -L \/\1\2 \1\2/'  \
>             | sed '/.*=>.*/d'; done | sh -s

>     # The shared files for ghostscript...
>           cp -L -r /usr/share/ghostscript usr/share
>     # The shared files for ImageMagick
>           cp -L -r /usr/lib/ImageMagick* usr/lib

>     ### Now, assuming that you have test.ly in /mnt/lilyloop/lilyhome,
>     ### you should be able to run:
>     ### Note that /$lilyprefix/bin/lilypond is a script, which sets the
>     ### LD_LIBRARY_PATH - this is crucial
>           /$lilyprefix/bin/lilypond -jlily,lily,/mnt/lilyloop,/lilyhome test.ly

### Footnotes

[1] The status of GUILE is not reset after processing a `.ly` file, so be careful not to change any system defaults from within Scheme.

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#### LilyPond — Usage