if i have created a file consisting of lines, with say four words per line separated by a space, andsay i typed this command into vi;
:%s/\(\a\+\)\s*\(\a\+\)\s*\(\a\+\)\s*\(\a\+\)/\4-\3-\2-\1/
what would this command do to the file and how would it work exactly. i am very new to linux and have tried to understand the question but cannot. i dont have access to a linux machine until next week so cant try it. plz help!