Read from STDIN

[mielvds]

From a prior discussion:

aha I see! Well too bad you can't do fx -q imma-artists.sparql -o imma-artists.xml -f xml | fx -q imma-artist.sparql - -p "artists/?artistNickname.jsonld" -f json :)

I haven't thought of getting STDIN, not impossible, but it would probably look more like:

fx -q imma-artists.sparql -f xml | fx -q imma-artist.sparql -i -p "artists/?artistNickname.jsonld" -f json` -- where -i without argument would attempt to catch STDIN...

Originally posted by @enridaga in #213 (reply in thread)

Could stdin be implemented, for instance for piping JSON into SA?

Expected behaviour:

• other that the source of input, it should behave the same as reading the data from file
• an empty -i means reading from stdin
• when -i is empty,-f is mandatory and the CLI should complain if it's missing.

And I don't know how useful this is, but perhaps something like

    SERVICE <x-sparql-anything:> {
        fx:properties fx:location <x-sparql-anything:stdin> .
        ?tvSeries xyz:name ?seriesName .
        ?tvSeries xyz:stars ?star .
        ?star fx:anySlot "Courteney Cox" .
    }

[luigi-asprino]

6978afc introduces the read-from-std-in option which allows users to pass the data source through the standard input channel.
It is a boolean option and its default value is false.
When it is set as true the engine reads from stdin and sets the input as value for the content option
Therefore, the input from the std is processed as inline content (and the inline content is possibly overwritten by the input from the std in).