UNIX for Advanced & Expert Users

dog, cat, 1, 2, 3
reverse, 7, 9, i, tell, you

3, 2, 1, cat, dog
you, tell, i, 9, 7, reverse

echo dog, cat, 1, 2, 3 |awk '{for(i=NF;i>1;i--) printf $i OFS;print $1}' FS=, OFS=,
 3, 2, 1, cat,dog

$ ruby -F"," -ane '$F[-1].chomp!; $F.reverse!; print "#{$F.join(",")}\n"' file
 3, 2, 1, cat,dog
 you, tell, i, 9, 7,reverse

perl -F, -lane'
  print join ",", reverse @F
  ' infile

ruby -F, -lane'
  print  $F.reverse.join ","
  ' infile