passing two sequences to application with pipe

[Marc Logghe]

Hi,
I know you can pipe a sequence (without the need to saving it to a file
first) into an EMBOSS application using the -filter argument like eg.
fastacmd -d nr -s p38398 | extractseq -filter -sformat ncbi -regions
'10-110'
But what if your EMBOSS applicion expects two input sequences like eg
diffseq ?
As far as I know, -filter takes only the first sequence, the second is lost.
I tried something (silly) like diffseq -filter -sformat ncbi -filter
-sformat ncbi or even numbering the arguments like diffseq -filter1 -filter2
but nothing worked out.
Is somethin like this possible anyhow ?
Marc