year end book closing

[grumps]

I keep my ledger as a text file.  As the last entry of the year on the 
ledger file I want to do a standard book closing.  To take total income 
and total expenses and use these to zero out the income and expenses 
accounts  and add the total of these to the equity account.  Is there a 
straight forward way to do this with a ledger entry?

jerry