When c-tree files are created and/or opened, their characteristics are partly determined by the filmod parameter. Some of these modes will be discussed in more detail in later chapters. filmod determines:
If a file is opened in a standard manner or in a special manner which avoids problems with limited file descriptors;
If a file is to be shared among multiple users or used exclusively by one user;
If a data file is composed of fixed-length or variable-length records;
The method of transaction management for the file;
If a file is to contain Resources;
If a file is to be a Superfile.
This section explains several important aspects of file modes: