fork download 
  1. BEGIN{
  2.   FS="_"
  3.   OFS=","
  4.   print "ID,group1,group2,group3"
  5. }
  6. FNR>1{
  7.   val=$0
  8.   $1=$1
  9.   print val,$0
  10. }
Success #stdin #stdout 0s 4396KB
comments (?)
stdin 
Some_header
a_b_c_1
d_e_f_2
g_h_i_3
stdout 
ID,group1,group2,group3
a_b_c_1,a,b,c,1
d_e_f_2,d,e,f,2
g_h_i_3,g,h,i,3
https://ideone.com/fWgggq
language:
AWK (gawk 4.2.1)
created:
5 years ago
visibility:
secret

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!