3.5 Filename extensions

You can use any file name extension for the input file, but if you do not use the recommended extension for a particular format you may need to manually specify the output format; for details, see Invoking lilypond-book. Otherwise, lilypond-book automatically selects the output format based on the input file name’s extension.

extension	output format
.html	HTML
.htmly	HTML
.itely	Texinfo
.latex	LaTeX
.lytex	LaTeX
.lyxml	DocBook
.tely	Texinfo
.tex	LaTeX
.texi	Texinfo
.texinfo	Texinfo
.xml	HTML

If you use the same file name extension for the input file than the extension lilypond-book uses for the output file, and if the input file is in the same directory as lilypond-book working directory, you must use --output option to make lilypond-book running, otherwise it will exit with an error message like “Output would overwrite input file”.