IBM Tivoli NetView for z/OS Programming: Pipes - IBM notice

PIPE SAFE
Streams
Stream Type Number Supported
Input 1
Output 1
Termination Conditions
SAFE terminates when the input stream disconnects.
Operand Descriptions
Usage Notes
Examples
208 Programming: Pipes
APPEND
Specifies that data is added after data that exists in the named SAFE. APPEND
is valid only when using a named SAFE (not used with the default SAFE
because it can contain no more than one message). The APPEND option is not
valid when SAFE is a first stage.
* Specifies that the default SAFE is used.
name
Specifies the 1- to 8-character name of a named SAFE. When the command
procedure group ends, all named SAFEs created by the group go away and the
associated storage is freed.
SEIZE
Use SEIZE for performance improvement when you do not need the contents
of the safe to remain in the safe after a read operation.
v The only access to a named SAFE is through the SAFE stage.
v Any REXX command list that is called by the REXX CALL instruction or is
invoked as a REXX function uses the same default SAFE as its caller.
v Because named safes are shared among command procedures, verify that the
names you select are not already in use for another purpose. For example, if
your command list invokes the WINDOW command (CNME1505), do not use
the safe names that are already used by the WINDOW command, such as
MSGS.
Example: Determining Whether a Named SAFE Exists
Use the following test to determine if a given named SAFE (MYSAFE) exists.
/* REXX sample command list */
’PIPE SAFE MYSAFE’,
’| VAR X’
IF SYMBOL(’X’) = ’LIT’ THEN
Say ’MYSAFE was not found.’
ELSE
Say ’MYSAFE was found.’
Example: Creating a Named SAFE That Contains a NULL
Message
A named SAFE can exist and can contain a 'NULL' message. The following
example shows how to create a named SAFE which contains a NULL message.