BT (Create Tape File)
- Purpose
- Write test data to a tape file.
- Usage notes
- Use this function to format a tape or create test data.
Specify a DDNAME for the tape. Also specify the record size and the number of records to be written.
- Options
- You can specify a fill character or fill pattern, a sequence field, a record format, and a block size.
- Related functions
-
- DSG
- Write test data to a data set
- INT
- Initialize a tape
- blksize
- If recfmout contains F, the actual block size; otherwise, the maximum block size. If recfmout contains B or S, blksize is required; otherwise, it is optional. The maximum is 65 535 (for V), 9 999 (for D), or 9 999 999 (otherwise). If the tape is processed by other utilities or standard access methods, you must also consider the operating system limits.
- ddname
- Refers to a DD or TSO ALLOC statement. To create a tape file with standard labels, specify AL or SL processing on the DD or TSO ALLOC statement.
- fillchar
- To fill each byte of each record with data, specify one of the
following:
- char
- A character, such as 0 to be written in each byte
- X'cc'
- A binary character, such as X'04' to be written in each byte
- AN
- To write alphanumeric characters (A to Z and 0 to 9)
- BIN
- To write binary characters (X'00' to X'FF')
- RAND
- To write random binary characters (X'00' to X'FF')
If you specify AN or BIN, characters are written in a “ripple” pattern. For example, if you specify AN, the first 3 records look like this:ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789A BCDEFGHIJKLMNOPQRSTUVWXYZ0123456789AB CDEFGHIJKLMNOPQRSTUVWXYZ0123456789ABCThe default is a blank.
- incr
- Increment value for the sequence field. The default is 10.
- keylen
- Length of the sequence field, from 1 to 9. The default is 8.
- keyloc
- Position (starting with 1) of the sequence field within the output records. If omitted, there is no sequence field.
- LABEL=BLP
- Specifies that bypass label processing is used. This parameter must be specified with the first File Manager function that uses the tape. For BLP processing requirements, see “Customizing the Security Environment” in the File Manager for z/OS Customization Guide.
- mm
- A 2-byte tape mode as shown in Tape density and mode values.
- nlrecs
- Number of logical records to be written. The maximum is 99 999 999.
- recfmout
- Record format for the output. Each value is a combination of the
following letters:
- B
- Blocked
- D
- Variable-length ISO/ANSI tape records
- F
- Fixed length
- S
- Spanned format
- U
- Undefined length
- V
- Variable length
- recsize
- Length of each logical record. The maximum is 9 999 999.
//BT JOB (acct),'name' Create SL Tape
//*
//FMBAT PROC
//FMBAT EXEC PGM=FILEMGR
//STEPLIB DD DSN=FMN.SFMNMOD1,DISP=SHR
//SYSPRINT DD SYSOUT=*
//SYSABEND DD SYSOUT=*
//SYSUDUMP DD SYSOUT=*
// PEND
//*
//* EXAMPLE BT JOB, SL processing
//* 67 RECORDS ARE WRITTEN TO A TAPE FILE,
//* V RECFM. THE OUTPUT FILE CONTAINS
//* ALPHANUMERIC CHARACTERS. THERE IS A
//* SEQUENCE FIELD AT POSITION 1.
//*
//STP0001 EXEC FMBAT
//BT1 DD DISP=(NEW,KEEP),UNIT=CART,
// VOL=(,RETAIN,,,SER=FMO001),
// LABEL=(1,SL),
// DSN=FMNUSER.BT05.A1V
//SYSIN DD *
$$FILEM BT OUTPUT=BT1,NLRECS=67,RECSIZE=1024,
$$FILEM KEYLOC=1,RECFMOUT=V,FILLCHAR=AN
$$FILEM EOJ
/*
//*
//* 12 RECORDS ARE WRITTEN TO A TAPE FILE,
//* FB RECFM. THE OUTPUT FILE CONTAINS '*'
//* CHARACTERS. THERE IS A SEQUENCE FIELD
//* AT POSITION 10.
//*
//STP0002 EXEC FMBAT
//BT2 DD DISP=(NEW,KEEP),UNIT=CART,
// VOL=(,RETAIN,,,SER=FMO001),
// LABEL=(2,SL),
// DSN=FMNUSER.BT05.A2FB
//SYSIN DD *
$$FILEM BT OUTPUT=BT2,NLRECS=12,RECSIZE=2048,
$$FILEM KEYLOC=10,INCR=100,
$$FILEM RECFMOUT=FB,FILLCHAR='*',
$$FILEM BLKSIZE=20480
$$FILEM EOJ
/*