I find myself adding data to files that need to be randomized. Well, just call awk from within vi and use the rand() function
:%!awk ‘BEGIN {srand()}; {if (int(rand()*4)==2) {printf(“\%s,S\n”,$0)} else print $0;}’
Maybe even a bit more comfortable AND this only adds to the lines if they don’t use SA, S or F
:%!awk ‘BEGIN {srand()} \!/(SA|S|F)$/ {if (int(rand()*4)==2) {sub(/$/,”FA”);}};{print}’