I’m not a big fan of the Sybase provided isql tool. I prefer the far better sqsh (pronounced skwish) replacement. it provides many features isql is lacking like searching through queries, using a ; to end a query and much better OS redirection of results.

Yes, sqsh can do much more but even if you don’t use all it features it still out-classes isql with ease and is a recommended tool for every dba. For an example of these more advanced features you should check out sybron.nl

Packages for EL5 and EL6 are provided on the source forge page for download. Note that you also need a Sybase OpenClient on the system.

Sqsh also works with replication server and even MSSQL.