lilypond-usage: Filename extensions

 
 3.5 Filename extensions
 =======================
 
 You can use any filename 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 SeeInvoking
 lilypond-book.  Otherwise, ‘lilypond-book’ automatically selects the
 output format based on the input filename’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 filename 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”.