ls command - define number of columns

No. ls does not have this capability (and few would want it to).

You will have to pipe | your ls output. Programs like sed or cut can sort out data as long as you know what your delimiter is. Most often in column spacing your delimiter is a tab.

However I don't know of many ways or reasons that you would want to split your ls output into columns. You can always pipe your output to more and it will make your data easier to read.

Just override the width parameter with 1:

ls -w 1

Works great for me!