GNU LilyPond program usage: 3.2.2 Command line options for lilypond

### 3.2.2 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 `svg`, `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 dumps every page as a separate ‘`SVG`’ file, with embedded fonts. You need a SVG viewer which supports embedded fonts, or a SVG viewer which is able to replace the embedded fonts with OTF fonts. Under UNIX, you may use Inkscape (version 0.42 or later), after copying the OTF fonts from the LilyPond directory (typically ‘`/usr/share/lilypond/VERSION/fonts/otf/`’) to ‘`~/.fonts/`’.

    `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

  ‘`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.

`-i,--init=file`

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

`-o,--output=FILE`

  Set the default output file to FILE. The appropriate suffix will be added (e.g. `.pdf` for pdf)

`--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!)

Other languages: español, deutsch.

#### Application Usage