HP OpenVMS Systems Documentation

HP OpenVMS DCL Dictionary

Creates a virtual mailbox named MBAn and assigns an I/O channel number to it. The /MAILBOX qualifier is required.

Note The following privileges are required: TMPMBX (temporary mailbox) to create a temporary mailbox (which is the default) CMEXEC (change mode to executive) to create a temporary mailbox (which is the default). Note: This requirement is temporary and will be removed in a future release. PRMMBX (permanent mailbox) to create a permanent mailbox (using the /PERMANENT qualifier) SYSNAM (system logical name) to place a logical name for a mailbox in the system logical name table GRPNAM (group logical name) to place a logical name for a mailbox in the group logical name table

To delete a mailbox, use the DELETE/MAILBOX command.

Format

CREATE/MAILBOX logical-name

Parameter

logical-name

Specifies a logical name for the new mailbox. The system creates the mailbox and sets the logical name to point to it.

Description

The CREATE/MAILBOX command creates a virtual mailbox.

Qualifiers

/BUFFER_SIZE=n

Specifies the number of bytes of system dynamic memory that can be used to buffer messages sent to the mailbox. If you do not specify /BUFFER_SIZE or specify it as 0, the operating system provides a default value from the DEFMBXBUFQUO system parameter.

/LOG

/NOLOG (default)

Displays the name of the new mailbox when it is created.

/MESSAGE_SIZE=n

Specifies the maximum size (in bytes) of a message that can be sent to the mailbox. The maximum value is 65535. If you do not specify /MESSAGE_SIZE or specify the value as 0, the operating system provides a default value from the DEFMBXMXMSG system parameter.

/PERMANENT

Specifies that the mailbox is to be permanent. By default, mailboxes are temporary.

/PROTECTION=(ownership[:access][,...])

Specifies protection for the mailbox.

• Specify the ownership parameter as system (S), owner (O), group (G), or world (W).
• Specify the access parameter as read (R), write (W), logical I/O (L), or physical I/O (P).

If no protection is specified, the mailbox template is used.

For more information about specifying protection codes, refer to the HP OpenVMS Guide to System Security.

/TEMPORARY (default)

Specifies that the mailbox is temporary. By default, mailboxes are temporary unless you specify /PERMANENT.

Example

$CREATE/MAILBOX/PERMANENT/MESSAGE_SIZE=512/LOG MY_MAILBOX
%CREATE-I-CREATED, MBA38: created
$SHOW DEVICE MBA38/FULL
Device MBA38:, device type local memory mailbox, is online,
    record-oriented device, shareable, mailbox device.
 Error count              0  Operations completed                0
 Owner process           ""  Owner UIC                    [SYSTEM]
 Owner process ID  00000000  Dev Prot  S:RWPL,O:RWPL,G:RWPL,W:RWPL
 Reference count          0  Default buffer size               512

      

In this example, a permanent mailbox is created with the logical name MY_MAILBOX. The SHOW DEVICE command displays the full characteristics of the mailbox.