How to use awk command(file) with file command?

how can i call awk file "average.awk" (code as follows) with file commands like ls -s...

#!/bin/awk -f
BEGIN {
# How many lines
    lines=0;
    total=0;
}
{
# this code is executed once for each line
# increase the number of files
# lines++;
# increase the total size, which is field #1
        if ($1 != "total" ) lines++;
    total+=$1;
}
END {
# end, now output the total
    print lines " lines read";
    print "total is ", total;
    if (lines > 0 ) {
        print "average is ", total/lines;
    } else {
        print "average is 0";
    }
}

You can simply pipe the output of your command:

command | average.awk

ls -l | awk -f average.awk