The EDTINFO macro enables you to obtain information from the EDT
and to check your device specification against the information in
the EDT. You
can use the EDTINFO macro to perform the following functions:
- Check groups. The EDTINFO macro determines whether the input
device numbers constitute a valid allocation group. The device numbers
are a valid allocation group if either of the following is true:
- For any allocation group in the EDT that contains at least one
of the device numbers specified in the input device number list, all of the device numbers in that group in the EDT
are contained in the input device number list
- None of the allocation groups in the EDT contain any of the numbers
specified in the input device number list.
If neither of these is the case, the device numbers are not
a valid allocation group.
- Check units. The EDTINFO macro determines whether the input device
numbers correspond to the specified unit name. The unit name is the
EBCDIC representation of the IBM® generic
device type or esoteric group name.
- Return unit name. The EDTINFO macro returns the unit name associated
with the UCB device type provided as input.
- Return unit control block (UCB) addresses. The EDTINFO macro
returns a list of UCB addresses associated with the unit name or device
type provided as input.
Note: The EDTINFO macro returns
UCB addresses only for below 16 megabyte UCBs for static and installation-static
devices with 3-digit device numbers. However, you can use the RTNDEVN
keyword with the EDTINFO macro to return a device number list for
devices that are dynamic, 4-digit or described by UCBs residing above
the 16-megabyte line.
The UCBINFO macro can then be used to obtain
device number information for a specific device number.
If
your program is authorized, running in supervisor state or with a
program key mask of 0-7, you can use the UCBLOOK macro to the obtain
the actual UCB address from a given device number. See, z/OS MVS Programming: Authorized Assembler Services Reference SET-WTO,
and z/OS MVS Programming: Authorized Assembler Services Guide for
the UCBLOOK macro.
- Return group ID. The EDTINFO macro returns the allocation group
ID corresponding to each UCB address specified as input.
- Return attributes. The EDTINFO macro returns general information
about the unit name or device type specified as input.
- Return unit names for a device class. The EDTINFO macro returns
a list of generic device types or esoteric group names associated
with the device class specified as input.
- Return UCB device number list. The EDTINFO macro returns the
UCB device number list associated with the unit name or UCB device
type specified as input. You can also specify that the following be
included in the list:
- Devices defined to the system as dynamic
- Devices defined with 4-digit device numbers
- Devices with UCBs defined above 16 megabytes
- Return maximum eligible device type. The EDTINFO macro returns
the maximum eligible device type (for the allocation and cataloging
of a data set) associated with the unit name or device type, recording
mode, and density provided as input. The maximum eligible device
type is the tape device type that contains the greatest number of
eligible devices compatible with the specified recording mode and
density.