I have two file
one ise set of gene it look like file (a)
cvpA katG
cvpA katE
recA katE

:
:
etc

the another file (b) one will look like
aat
katE
ppfA
cvpA
:
:
etc
My aim is
take all the gene pair from file(a)
so the condition atleast one gene belongs to file(b) gene
So My Out put will look like

cvpA katG --------cvpA
cvpA katE --------cvpA,katE
recA katE --------katE
:
:
: