Requesting dynamic unallocation

To request dynamic unallocation, specify free at the beginning of the parameter string.

BPXWDYN supports single data set allocation. Many of the common unallocation keys can be used. For detailed information about those common keys, see z/OS TSO/E Command Reference. Some additional keys are supported to access additional functions.

Table 1. Common keys used for dynamic unallocation
Common keys used for dynamic allocation	Action
DA(`data set name`[(`member name`)]) \| DSN(`data set name`[(`member name`)])	Specifies the data set name to free. The name must be fully qualified and can include a member name. Quotes are optional.
FI(name) \| DD(name)	Identifies the ddname to free.
KEEP \| DELETE \| CATALOG \| UNCATALOG	Overrides the data set disposition.
SPIN(UNALLOC)	Spins off a sysout data set at unallocation.
SYSOUT(class)	Overrides the output class.

The following additional keys are unique to BPXWDYN.

Table 2. Additional keys used for dynamic unallocation
Additional keys for dynamic allocation	Action
DIAG (stem \| fdnum \| STDOUT)	Specifies that diagnostic information is to be displayed. The information includes a compile time stamp, the input string, key parsing information for subsequent keys, and the list of generated text units. Specify STDOUT to send output information to the standard REXX output stream.
MSG (WTP \| default.S99MSG.\| stemname \| fdnum)	Directs allocation messages to your job log (WTP), a REXX stem, or a file identified by a file descriptor number. If this key is not specified, messages are returned in the S99MSG. stem, if possible. If BPXWDYN was not called from a REXX environment, the messages will be lost. WTP should be specified to obtain messages.
SHORTRC	If the dynamic allocation fails, the dynamic allocation error code (S99ERROR) is returned in R15 and the information code is not returned. This is useful if the application can only process R15 as a halfword, such as with PL/I.
TU(`hex-tu-value`)	Builds an allocation text unit (TU) from the specified string. For example, `alloc tu(000100010002c1c2)` is equivalent to `alloc fi(ab)`. TU can be used multiple times in an allocation request.