How do I extract the filename from a path AWK if I have different length filenames with a path?

I have an awk script that counts the average of rows from every file from a given directory and its subdirectories and I have to print the filename and the average from a file like this example.c : 5. So I have filenames like this ../labor1/munka/hazik_pagi4188/hazik/c_prog/lab1/fork2.c and I want to get like this fork2.c (I have different length file names with path)

sub("[^\/]*$","")

awk: warning: escape sequence `\/' treated as plain `/'