Comment 2 for bug 889402

1) If we could agree on options list I could prepare a patch.

2) What about adding a new option like "--filetype={pdf, ps, img}", where a user invokes inkscape with a number of files and they are all converted to the specified filetype. Like:
> inkscape -f 1.svg 2.svg 3.svg --filetype=pdf

3) Short answers is a test I have made (which I have improved further from last time)

1. executing a new process
>inkscape -f 1.svg -A 1.pdf
>inkscape -f 2.svg -A 2.pdf
>inkscape -f 3.svg -A 3.pdf
results in average time for document export of 0.71 seconds per document

2. executing the modified code with
>inkscape -f 1.svg 2.svg 3.svg -A unused.pdf
results in average time for document export of 0.25 seconds per document

3. executing with the interactive shell
> for i in {1..10}; do echo " -f file-$i.svg -A file-$i.pdf"; done | inkscape --shell
results in average time for document export of 0.41 seconds per document