Chapter 4. DMKDIR-The Directory Program
Introduction
Tbe DMKDIR program builds the VM/370 directory on a volume previously formatted
by tbe Fermat/Allocate program, using
cylinders that were previously allocated
for use as directory space. Under the control of the VM/370 system,
tbe new directory is dynamically swapped
and placed in use provided the directory
bas been created without errors, on a
volume in the system-owned list, and
provided the user class is A, B, or C.
The new directory can be built se that
it does net overlay an existing directory.
To do this, allocate Eneugb space fer two
directories or allocate for a new directory each time tbe directory is
created.
The directory program can be
standalone or under the control of
The CMS DIRECT command invokes
directory program under CMS. run CMS. the
Chapter 4. t!KDIR--The Directory Progra. 81

Method of Operation
This section describes the operation of the VM/370 Directcry Frogram. Figure 4-1 shows
the relationship of the Method of Operation
diagrams.
Diagram 4-1 describes the
functions of the Directory program. Diagram 4-2 Diagram 4-3 DMKDIR DMKDIR major
Diagram 4-1
Overview of
the Directory
Program Control Statement Control Statement
Processing Processing Diagrams 4-2, 4-3, and 4-4 describe the
control statement processing and the
resulting action. Diagram 4-5 shows the functions
performed before the program terminates. Diagram 4-4 Diagram 4-5 DMKDIR Directory Control Statement
Exit
Processing
Figure 4-1. Key to the Directory Program Method of Operation Diagrams 82 IBM VM/370 Service Routines Program Logic