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Operational Details

OSTARXMT

The OSTARXMT program operates as follows:

1.	Prompts for an output data set name.

The data set must not already exist.

2.	Prompts for input data set names.

3.	For each input data set, it does the following:

−	Copies the data set to a sequential work data set, with LRECL=80 and RECFM=FB, using the TSO TRANSMIT command.

−	Appends the work data set to the output XMT data set, with LRECL=88 and RECFM=FB, adding an error detection checksum generated by XORing the data both vertically and horizontally.

4.	Compresses the XMT file into an XM1 file and then deletes the XMT file.

The new file name is the same as the XMT file except the last qualifier is XM1.

Data Set Formats

If a single large sequential data set is used as input (for example, an SVC dump), the XM1 file format is not used. Instead, an XM2 format data set is created. The difference between the two formats is, for the XM2 format, TSO TRANSMIT and Error Detection Code are bypassed and only data compression is performed. Creating an XM2 data set takes a fraction of the time it takes to create an XM1 data set and an XM2 data set is slightly smaller because error detection information is not added. The output data set can then be transmitted, as a single data set, by any of the available methods.

File Format Summary:

 

Suffix	LRECL	BLKSIZE	Description
.XMT	88	n*88	Ensures data integrity by error checking.
.XM1	1024	n*1024	Compressed version of .XMT files. Ensures data integrity by error checking.
.XM2	1024	n*1024	Compressed version of original file. No error checking.
.XM1Fn	1024	n*1024	Compressed version of original file but composed of “chunks.” OSTARREC will combine series of files XM1F1,2,3..n into one final uncompressed file.

 

Keep suffix on files when you FTP them to TIBCO Support so that OSTARREC will be able to automatically use the correct algorithm to unwrap the file. Always FTP with the binary option.

CHUNKSIZE Option

If the data set is excessively large and you have a slow Internet connection, you can modify the OSTARXMT source to set the CHUNKSIZE value. This divides the XM1 or XM2 data set produced into multiple XM1Fnn or XM2Fnn data sets to facilitate FTP transmission.

Bypassing Prompts

You can bypass the prompting for data set names using the following methods:

•	Provide the name of a control data set as a parameter to the program. The format of this data set is as follows:

−	Record 1 contains the words OSTARXMT CONTROL.

−	Record 2 contains the output data set name in any valid TSO format.

−	Subsequent records contain input data set names, one per record.

•	Provide a single input data set name. For example, you can type OSTARXMT beside a data set in ISPF 3.4. The output data set has the same data set name except that the last qualifier is changed to XM1.

OSTARREC

The OSTARREC program accepts the input data set name. For example, you can type OSTARREC against a data set in any of the formats in ISPF 3.4.

 

Copyright © Cloud Software Group, Inc. All Rights Reserved