I have two fasta files, with the same headers/names for the sequences but different sequences. 
I would like to combine them into one file, so that each sequence has the same name but is a combination of both sequences. 
My preferred language is bash script, but I'm open to other suggestions. 
thanks. 
assuming there  are only twho lines per sequence (title/dna) and they are ordered the same way.

    paste  f1.fa f2.fa | sed -e 's/\t>.*//' -e 's/\t//'