SMF record mapping conventions

This section describes the SMF record mapping conventions that File-AID uses for member naming, using USE and NEXT commands for multiple 01-level maps, generic layouts, and displaying the value of the record type field.

Member naming convention

Naming conventions for the SMF mapping facility members are as follows:

1. SCxxxxx selection criteria members only exist in XREF library
2. SLxxxxx XREF members only exist in XREF library
3. SMxxxxx PL/I source layouts reside in PLI library

Multiple 01 Level Maps and the Commands USE and NEXT

Each PL/I source member in the PLI library and its corresponding map member in XREF may contain one or more “01 LEVEL” layouts. Multiple “01 LEVEL” layouts are needed to handle special mapping requirements for a given record type or to describe multiple variations of a record type that may be present in the data. Each “01 LEVEL” represents a distinct “layout” and may be based at any location in a data record by using the primary command “USE”.

The USE command is provided so that you can specify a layout and a position in the record to begin mapping.

Syntax of the USE command is:

      USE { offset }   { Copybook name }
           { NEXT    }   { *                    }
           { PREV     }The NEXT command is provided to invoke XREF logic to automatically select a layout for the next segment of record data. When no XREF is active, the NEXT command can be used to place a layout at the byte location in the record that immediately follows the last byte mapped by the current layout.

Syntax of the NEXT command is:

NEXT { n } { Copybook name }To learn more about the USE and NEXT commands, see Primary-command-descriptions or File-AID online tutorial.

The NEXT and USE commands are usually used in conjunction with an XREF and multiple layouts when mapping “segmented” records. A segmented record is a record type that has a base section described by one record layout and one or more following segments of data each of which is described by a different layout. SMF record type 22 (Configuration) is an example of a segmented record.

Should you need to change a layout or XREF, use the XREF utility, option 7, to build and maintain the automatic layout XREFs. See Validating-and-maintaining-your-SMF-mapping-libraries.

SMFGNRIC and SMNGNRIC - Generic SMF Record Layouts

Whenever the master XREF (SLFALL - offline, SLNALL - online) encounters an SMF record for which no map is provided, a generic layout (SMFGNRIC - offline, SMNGNRIC - online) is displayed.

The generic layout shows the basic header fields of the SMF record and also may display some of the data in hex.

Displaying Decimal Value of Record Type

The formatter command DISPLAY n BIN (where “n” is a field number of some layout field) can be used to convert a character or hex field to its decimal value. This command is very helpful in decoding the RECORD_TYPE field (field number 2 offline, field number 4 online) so that the decimal value of the SMF record type is presented instead of the hex or character representation of the record type value.

The RECORD_TYPE field is defined as CHAR (1) and is displayed as one character if the hex value of the record type is a displayable character. However, the hex value of the record type field is usually a non-displayable character, and is therefore shown as two hex digits (X'xx') and is highlighted for emphasis. In any case, use the DISPLAY n BIN command to see the decimal value of the record type field.