histogram.awk

#!/usr/bin/awk -f

BEGIN {
	FS = ",";
	session_id_ticket = 0
}

function update_array(len, array)
{
	if (len != 0)
	{
		session_id_ticket++;
		if (len <= 128)
		{
			array[128]++;
		}
		else if (len <= 256)
		{
			array[256]++;
		}
		else
		{
			array[512]++;
		}
	}	
}

{
	update_array(length($3) / 2, array)
	update_array(length($4) / 2, array)
}

END {
	printf "0 < session_ticket_len <= 128: %d, %.1f%%\n", array[128], array[128] / session_id_ticket * 100;
	printf "128 < session_ticket_len <= 256: %d, %.1f%%\n", array[256], array[256] / session_id_ticket * 100;
	printf "256 < session_ticket_len: %d, %.1f%%\n", array[512], array[512] / session_id_ticket * 100;
}