Swap two columns - awk, sed, python, perl

Question

I\'ve got data in a large file (280 columns wide, 7 million lines long!) and I need to swap the first two columns. I think I could do this with some kind of awk for loop, to

Answer 1

You can do this by swapping values of the first two fields:

awk ' { t = $1; $1 = $2; $2 = t; print; } ' input_file