Использование gawk:
ls -l /etc/rc*.d/* | gawk 'match($0, /rc([0-6S]).d.*\/(.*)$/, a) {l[a[2]]=l[a[2]]a[1]","}; END{for(v in l){print v,substr(l[v],1,length(l[v])-1)}}'
Пример вывода:
$ ls -l /etc/rc*.d/* | gawk 'match($0, /rc([0-6S]).d.*\/(.*)$/, a) {l[a[2]]=l[a[2]]a[1]","}; END{for(v in l){print v,substr(l[v],1,length(l[v])-1)}}' | egrep README
README 0,1,2,3,4,5,6,S