Question

I have an input data with three columns (tab separated) like this:

  a  mrna_185598_SGL 463
  b  mrna_9210_DLT   463
  c  mrna_9210_IND   463
  d  mrna_9210_INS   463
  e  mrna_9210_SGL   463

How can I use sed/awk to modify it into
four columns data that looks like this:

a  mrna_185598 SGL   463
b  mrna_9210   DLT   463
c  mrna_9210   IND   463
d  mrna_9210   INS   463
e  mrna_9210   SGL   463

In principle I want to split the original “mrna” string into 2 parts.

Answer 1

something like this

awk 'BEGIN{FS=OFS="\t"}{split($2,a,"_"); $2=a[1]"_"a[2]"\t"a[3] }1'  file

output

# ./shell.sh
a       mrna_185598     SGL     463
b       mrna_9210       DLT     463
c       mrna_9210       IND     463
d       mrna_9210       INS     463
e       mrna_9210       SGL     463

use nawk on Solaris

and if you have bash

while IFS=$'\t' read -r a b c
do
    front=${b%_*}
    back=${b##*_}
    printf "$a\t$front\t$back\t$c\n"
done <"file"