Shell Programming and Scripting

Hi there
I would like to search a file for a certain pattern, but i don't know the exact pattern i need to search for.
What i do know is that i need to search for the pattern that exists the most in a certain file.
so if a file looksike this:
summer, summer, winter, spring, summer summer.
i would need a grep command to display summer, while summer is the pattern that exists the most.
regards chilly

$> grep $(grep -o '\b[^[:space:]]*\b' infile |awk '{A[$1]++}END{for (i in A) print A[i],i}'|sort -n|tail -1|cut -d ' ' -f2) infile
summer, summer, winter, spring, summer summer.
i would need a grep command to display summer, while summer is the pattern that exists the most.

$> grep -o '\b[^[:space:]]*\b' infile |awk '{A[$1]++}END{for (i in A) print A[i],i}'|sort -n|tail -1|cut -d ' ' -f2
summer

while(<>)  {
    @arr = split /\b/, $_;
    foreach (@arr)  {
        $hash{$_}++ if not ( /\s+/ || /,/ );
    }
}

@arr = sort { $hash{$b} <=> $hash{$a} } keys %hash;
print $arr[0];