invoking stdin: a use case?

[Federico Bruni]

Hi LilyPonders,

in Usage 1.2:

"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."

I wonder what's the use of stdin.  Can you show a use case?

I'm translating the Usage manual so I want to be sure that I've
understood it correctly. I guess that the dash **replaces** the file, so
the command is:

lilypond -


BTW, I think that in the following sentence:

"When ‘filename.ly’ is processed it will produce ‘filename.ps’ and
‘filename.pdf’ as output."

‘filename.ps’ should be removed (or at least you should say that .ps
file will be converted to .pdf and then deleted), otherwise new users
might wonder where the .ps file has gone.

Cheers,
Federico