I have one folder with 25000 fasta files named Rnor.01.fa, Rnor.02.fa.... And another folder with 25000 fasta files named Rrat.01.fa, Rrat.02.fa....
I want to concatenate Rnor.01.fa and Rrat.01.fa into a file Rnor_Rrat.01.fa and likewise Rnor.02.fa with Rrat.02.fa to ultimately have 25000 files each containing fasta sequences from each species.
I am new to programing and can't seem to figure out how to use cat to be able to do so.
Any help would be appreciated. Thank you.