isCOBOL uses the c-tree interface in one of the following cases:

The isCOBOL Framework becomes a client process that connects to a listening c-tree Server. To provide this connection, isCOBOL loads the ctree client library (ctree.dll on Windows, libctree.so on Linux) which must be available in the library path and must be the same version of the listening c-tree Server. A copy of this library is provided along with isCOBOL and it’s of the same version as the latest c-tree server available for download at Veryan’t web site. The library is installed in the bin folder on Windows and in the native/lib folder on Linux/Unix). You can replace this library if you need to work with a different version of c-tree.

isCOBOL can create c-tree files directly into the c-tree SQL Server so they are available as database tables for external SQL tools. Consult Creating c-tree files into c-tree SQL Server from the COBOL Program chapter for details.

In order to bring existing c-tree files into the SQL Server, instead, the ctutil utility must be used. Consult Registering existing c-tree files in c-tree SQL Server chapter for details.

The c-tree File Connector allows you to work on c-tree files managed by c-tree by separating ISAM native access from java process. This solution is suggested when working with third party application servers (e.g. Apache Tomcat).

isCOBOL uses the file connector interface in one of the following cases:

isCOBOL includes a copy of the c-tree client library in the bin directory on Windows and in the native/lib directory on Linux/Unix. This library is always up to date with the latest c-tree server distributed by Veryant. If it doesn’t suit your needs, consider replacing this library with the one found in the c-tree server’s installation, under the drivers/ctree.cobol folder, with the following criteria.

Until version 11.9 a c-tree client library was able to connect to a c-tree server of an older version, as long as the major release is the same. Since version 11.9, the default ctree library installed under drivers/ctree.cobol/iscobol is no longer able to connect to c-tree servers of a previous version (e.g. 11.6).

If you need to connect to a c-tree server of a previous version, use the library installed under drivers/ctree.cobol/iscobol.noGT32Kfiles instead.

If you need to connect to a c-tree server version 10 or lower, then use the c-tree client library installed along with that server.

The available file handler classes and their aliases may be different when working with previous c-tree versions. The following table lists the file handlers available for the various c-tree versions:

[B] Deprecated since isCOBOL 2016 R1.