@c -*- coding: latin-1; mode: texinfo; -*-
@node Running LilyPond
@chapter Running LilyPond

This chapter details the technicalities of running LilyPond.


@menu
* Invoking lilypond::
* Error messages::
* Updating files with convert-ly::
* Reporting bugs::
* Editor support::
@end menu

@node Invoking lilypond
@section Invoking lilypond
@cindex Invoking LilyPond
@cindex command line options
@cindex options, command line
@cindex switches


The @code{lilypond} executable may be called as follows from the command line.

@example
lilypond [@var{option}]@dots{} @var{file}@dots{}
@end example


When invoked with a filename that has no extension, the @file{.ly}
extension is tried first.  To read input from stdin, use a
dash (@code{-}) for @var{file}.

When @file{filename.ly} is processed it will produce
@file{filename.tex} as output (or @file{filename.ps} for PostScript
output).  If @file{filename.ly} contains more than one @code{\score}
block, then the rest of the scores will be output in numbered files,
starting with @file{filename-1.tex}.  Several files can be specified;
they will each be processed independently.  @footnote{The status of
GUILE is not reset after processing a @code{.ly} file, so be careful
not to change any system defaults from within Scheme.}


@section Command line options

The following options are supported:

@table @code

@item -e,--evaluate=@var{expr}
Evaluate the Scheme @var{expr} before parsing any @file{.ly} files.
Multiple @code{-e} options may be given, they will be evaluated
sequentially.  The function @code{ly:set-option} allows access to
some internal variables.  Use @code{-e '(ly:option-usage)'} for more
information.

@item -f,--format=@var{format}
which formats should be written.  Choices are @code{svg}, @code{ps},
@code{pdf}, @code{png}, @code{tex}, @code{dvi}.

@item -b,--backend=@var{format}
the output format to use for the back-end.  Choices are
@table @code
@item tex
for @TeX{} output, to be processed with La@TeX{}.  If present, the file
@file{file.textmetrics} is read to determine text extents.
@item texstr
dump text strings to @file{.texstr} file, which can be run through
(La)@TeX{}, resulting in a @code{.textmetrics} file, which contains the
extents of strings of text.
@item ps
 for PostScript.
@cindex PostScript output

  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.  
  
@item eps
 for encapsulated PostScript.  This dumps every page (system) as a separate
@file{EPS} file, without fonts, and as one collated @file{EPS} file with
all pages (systems) including fonts.

This mode  is used by default by lilypond-book.

@item svg
 for SVG (Scalable Vector Graphics)
@cindex SVG (Scalable Vector Graphics)
@item scm
 for a dump of the raw, internal Scheme-based drawing commands.
@cindex Scheme dump
@end table
 
@cindex output format, setting

@item -h,--help
Show a summary of usage.

@item --include, -I=@var{directory}
Add @var{directory} to the search path for input files.
@cindex file searching
@cindex search path

@item -i,--init=@var{file}
Set init file to @var{file} (default: @file{init.ly}).

@item -o,--output=@var{FILE}
Set the default output file to @var{FILE}.  The appropriate
suffix will be added (ie @code{.pdf} for pdf, @code{.tex}
for tex, etc).

@item --ps
Generate PostScript.

@item --dvi
Generate DVI files.  In this case, the @TeX{} backend should be
specified, i.e., @code{-f tex}.

@item --png
Generate pictures of each page, in PNG format.  This implies @code{--ps}.

@item --pdf
Generate PDF.  This implies @code{--ps}.

@item --preview
Generate an output file containing the titles and the first system

@item --no-pages
Do not generate the full pages.  Useful in combination with
@code{--preview}.

@item -s,--safe
Do not trust the @code{.ly} input.

When LilyPond formatting is available through a web server, the
@code{--safe} @b{MUST} be passed.  This will prevent inline Scheme
code from wreaking havoc, for example

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

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

In addition, @code{--safe} disallows @code{\include} directives and
disables the use of backslashes in @TeX{} strings.

In @code{--safe} mode, it is not possible to import LilyPond variables
into Scheme.

@code{--safe} does @emph{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.

@item -v,--version
Show version information.

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

@item -w,--warranty
Show the warranty with which GNU LilyPond comes. (It comes with
@strong{NO WARRANTY}!)
@end table


@section Environment variables

For processing both the @TeX{} and the PostScript output, the
appropriate environment variables must be set.  The following scripts
do this:

@itemize @bullet
@item @file{buildscripts/@/out/@/lilypond@/-profile}
(for SH shells)
@item @file{buildscripts/@/out/@/lilypond@/-login} (for C-shells)
@end itemize

They should normally be sourced as part of the login process.  If these
scripts are not run from the system wide login process, then you must
run them yourself.

@cindex installing LilyPond

If you use sh, bash, or a similar shell, then add the following to
your @file{.profile}:
@example
. @var{/the/path/to/}lilypond-profile
@end example

If you use csh, tcsh or a similar shell, then add the following to
your @file{~/.login}:
@example
source @var{/the/path/to/}lilypond-login
@end example

Of course, in both cases, you should substitute the proper location of
either script.

These scripts set the following variables:
@table @code
@item TEXMF
To make sure that @TeX{} and lilypond find data files (among
others @file{.tex}, @file{.mf}, and @file{.tfm}),
you have to set @code{TEXMF} to point to the lilypond data
file tree.  A typical setting would be
@example
@{/usr/share/lilypond/2.4.0,@{!!/usr/share/texmf@}@}
@end example

@end table


@cindex PostScript
@cindex TEXMF
@cindex printing postscript

The binary itself recognizes the following environment variables:
@table @code
@item LILYPONDPREFIX
This specifies a directory where locale messages and
data files will be looked up by default.  The directory should contain
subdirectories called @file{ly/}, @file{ps/}, @file{tex/}, etc.

@item LANG
This selects the language for the warning messages.
@end table

@cindex LANG
@cindex LILYPONDPREFIX

@node Error messages
@section Error messages

@cindex error messages
Different error messages can appear while compiling a file:

@table @emph
@cindex warning

@item Warning
Something looks suspect.  If you are requesting something out of the
ordinary then you will understand the message, and can ignore it.
However, warnings usually indicate that something is wrong with the
input file.

@item Error
Something is definitely wrong.  The current processing step (parsing,
interpreting, or formatting) will be finished, but the next step will
be skipped.

@cindex error
@cindex fatal error
@item Fatal error
Something is definitely wrong, and LilyPond cannot continue.  This
happens rarely.  The most usual cause is misinstalled fonts.

@cindex trace, Scheme
@cindex call trace
@cindex Scheme error
@item Scheme error
Errors that occur while executing Scheme code are caught by the Scheme
interpreter.  If running with the verbose option (@code{-V} or
@code{--verbose}) then a call trace of the offending
function call is printed.

@cindex Programming error
@item Programming error
There was some internal inconsistency.  These error messages are
intended to help the programmers and debuggers.  Usually, they can be
ignored.  Sometimes, they come in such big quantities that they obscure
other output.  In this case, file a bug-report.

@item Aborted (core dumped)
This signals a serious programming error that caused the program to
crash.  Such errors are considered critical.  If you stumble on one,
send a bug-report.


@end table

@cindex errors, message format
If warnings and errors can
be linked to some part of the input file, then error messages have the
following form

@example
@var{filename}:@var{lineno}:@var{columnno}: @var{message}
@var{offending input line}
@end example

A line-break is inserted in the offending line to indicate the column
where the error was found.  For example,

@example
test.ly:2:19: error: not a duration: 5:
  @{ c'4 e'5
             g' @}
@end example

These locations are LilyPond's best guess about where the warning or
error occured, but (by their very nature) warnings and errors occur
when something unexpected happens.  If you can't see an error in the
indicated line of your input file, try checking one or two lines
above the indicated position.


@node Updating files with convert-ly
@section Updating with @command{convert-ly}

The LilyPond input syntax is routinely changed to simplify it or improve
it in different ways.  As a side effect of this, the LilyPond interpreter
often is no longer compatible with older input files.  To remedy this,
the program @command{convert-ly} can be used to deal with most of the
syntax changes between LilyPond versions.

It uses @code{\version} statements in the input files to detect the old
version number.  In most cases, to upgrade your input file it is sufficient
to run

@example
covert-ly -e myfile.ly
@end example

If there are no changes to myfile.ly and file called myfile.ly.NEW
is created, then myfile.ly is already updated.

To upgrade LilyPond fragments in texinfo files, use

@example
convert-ly --from=... --to=... --no-version *.itely
@end example

In general, the program is invoked as follows:

@example
convert-ly [@var{option}]@dots{} @var{file}@dots{}
@end example


The following options can be given:

@table @code
@item -e,--edit
Do an inline edit of the input file.  Overrides @code{--output}.

@item -f,--from=@var{from-patchlevel}
Set the version to convert from.  If this is not set, @command{convert-ly}
will guess this, on the basis of @code{\version} strings in the file.

@item -o,--output=@var{file}
Set the output file to write.  

@item -n,--no-version
Normally, @command{convert-ly} adds a @code{\version} indicator 
to the output.  Specifying this option suppresses this.  

@item -s, --show-rules
Show all known conversions and exit.

@item --to=@var{to-patchlevel}
Set the goal version of the conversion.  It defaults to the latest
available version.

@item -h, --help
Print usage help.
@end table

@command{convert-ly} always converts up to the last syntax change handled by
it.  This means that the @code{\version} number left in the file is
usually lower than the version of @command{convert-ly} itself.

@refbugs

Not all language changes are handled.  Only one output option can be
specified.


@c  We might want to make this a completely new section, along with more
@c  info about how to upgrade old input files.  -gp

@ignore
Copy and paste from CVS, last updated
Feb 14, 2005

http://savannah.gnu.org/cgi-bin/viewcvs/*checkout*/lilypond/lily-bugs/bugs/convert-ly.txt?rev=HEAD&content-type=text/plain
@end ignore
@verbatim

There are a few things that the convert-ly cannot handle.  Here's a list of limitations
that the community has complained about.

This bug report structure has been chosen because convert-ly has a structure that doesn't
allow to smoothly implement all needed changes.  Thus this is just a wishlist, placed
here for reference.

1.6->2.0:
 Doesn't always convert figured bass correctly, specifically things like {< >}. Mats' comment on working around this:
   To be able to run convert-ly
   on it, I first replaced all occurencies of '{<' to some dummy like '{#'
   and similarly I replaced '>}' with '&}'. After the conversion, I could
   then change back from '{ #' to '{ <' and from '& }' to '> }'.
 Doesn't convert all text markup correctly. Only very simple cases are fixed.
2.0->2.2:
 Doesn't handle \partcombine
 Doesn't do \addlyrics => \lyricsto, this breaks some scores with multiple stanzas.
2.2->2.4:
 \turnOff (used in \set Staff.VoltaBracket = \turnOff) is not properly converted.
2.4.2->2.5.9
 \markup{ \center-align <{ ... }> } should be converted to:
 \markup{ \center-align {\line { ... }} }
 but now, \line is missing.
@end verbatim


@node Reporting bugs
@section Reporting bugs

@cindex bugs
@cindex reporting bugs

If you have input that results in a crash or an erroneous output, then
that is a bug.  We try to respond to bug-reports promptly, and fix them as
soon as possible.  Help us by sending a defective input file, so we can
reproduce the problem.  Make it small, so we can easily debug the
problem.  Don't forget to tell which version of LilyPond you use!  Send
the report to @email{bug-lilypond@@gnu.org}.

When you've found a bug, have a look at our
@uref{http://@/lilypond@/.org/@/doc/@/v2.3/@/bugs/,bug database} to see if
it has already been reported.  You could also try to do a few searches
on the mailing list for the bug.  Sometimes the bug will have already
been reported and a fix or workaround is already known.

Here is an example of a good bug report:

@example
It seems that placement of accidentals is broken.  In the
following example, the accidental touches the note head.

Using Mac OSX 10.3.5, fink package lilypond-unstable

\version "2.3.22"
\relative c''@{
   a4 b cis d
@}
@end example

@lilypond[quote]
\version "2.3.22"
\relative c''{
  \override Accidental #'extra-offset = #'(1.0 . 0)
  a4 b cis d
}
@end lilypond

@node Editor support
@section Editor support

@cindex editors
@cindex vim
@cindex emacs
@cindex modes, editor
@cindex syntax coloring
@cindex coloring, syntax

There is support from different editors for LilyPond.

@table @asis
@item Emacs
Emacs has a @file{lilypond-mode}, which provides keyword
autocompletion, indentation, LilyPond specific parenthesis matching
and syntax coloring, handy compile short-cuts and reading LilyPond
manuals using Info.  If @file{lilypond-mode} is not installed on your
platform, then read the
@ifhtml
@uref{../../../topdocs/out-www/INSTALL.html,installation instructions}.
@end ifhtml
@ifnothtml
installation instructions.
@end ifnothtml

@item VIM

For @uref{http://@/www@/.vim@/.org,VIM}, a @file{vimrc} is supplied, along
with syntax coloring tools.  For more information, refer to the
@ifhtml
@uref{../../../topdocs/out-www/INSTALL.html,installation instructions}.
@end ifhtml
@ifnothtml
installation instructions.
@end ifnothtml


@item JEdit

The @uref{http://@/www@/.jedit@/.org/,jEdit} editor has a LilyPond plugin.
This plugin includes a DVI viewer, integrated help and viewing via
GhostScript.  It can be installed by doing @key{Plugins > Plugin
Manager}, and selecting @code{LilyTool} from the @key{Install} tab.

@end table

All these editors can be made to jump into the input file to the source
of a symbol in the graphical output.  See @ref{Point and click}.