Sybase officially does not supply any utility to view the contents of the log. CA used to sell a Product called Log Analyzer for Sybase. Not sure if they still do?
Whitesands, I believe has something that can do on Sybase.
Otherwise try dbcc logtransfer ('scan', 'normal'), this is how Rep Server scans the log, the output is in LTL (Log Transfer Language). I have never tried this, I would say this will need trace 3604 enabled. Sorry, I'm no where near any Sybase servers, test it first on non-prod and show the output.