Bash sort by regexp

Question

I have something about 100 files with the following syntax

ahfsdjfhdfhj_EPI_34_fdsafasdf
asdfasdf_EPI_2_fdsf
hfdjh_EPI_8_dhfffffffffff
ffffffffffasdfsdf_EPI_         


        

Answer 1

 sed -e 's/EPI_/EPI /' file1 file2 ...|sort -n -k 2 -t ' '

Pipe that to sed -e 's/ /_/' to get back the original form.