IEBGENER

Enhanced Definition

IEBGENER is a standard IBM utility program in z/OS primarily used for copying, reformatting, and converting sequential data sets or members of partitioned data sets (PDS/PDSE). It provides a flexible way to manipulate data records without requiring custom application programs, making it a staple in batch processing environments.

Key Characteristics

- Core Functionality: Copies sequential data sets (PS) or individual members within partitioned data sets (PDS/PDSE) from an input data set (SYSUT1) to an output data set (SYSUT2).
- Data Manipulation: Can reformat records, change logical record length (LRECL), block size (BLKSIZE), and perform EBCDIC-to-ASCII or ASCII-to-EBCDIC character set conversions.
- JCL Driven: Controlled entirely through Job Control Language (JCL), using DD statements for input (SYSUT1), output (SYSUT2), messages (SYSPRINT), and optional control statements (SYSIN).
- No Control Statements Needed for Simple Copy: For a straightforward one-to-one copy, no SYSIN control statements are required; IEBGENER defaults to copying all records.
- Exit Support: Allows for user-written exit routines (e.g., specified via EXIT=IEBGENER in SYSIN or EXIT=name in EXEC statement) to perform custom processing on records before they are written to the output.
- Part of DFSMS: It is an integral component of the Data Facility Storage Management System (DFSMS) utilities provided with z/OS, ensuring its availability and integration within the operating system.

Use Cases

- Copying a Sequential Data Set: Duplicating an entire sequential file (e.g., a flat file, report output) to another location or a new data set for backup or processing by another application.
- Copying a PDS/PDSE Member: Extracting a specific member from a library to a sequential data set, or copying a member to another member within the same or a different library.
- Reformatting Data: Changing the record format (e.g., FB to VB), LRECL, or BLKSIZE of a data set, often used when preparing data for a different application or system.
- Character Set Conversion: Converting data from EBCDIC (native mainframe character set) to ASCII for transfer to distributed systems, or vice versa, facilitating data exchange.
- Generating Test Data: Creating small, simple sequential data sets containing specific records defined in the SYSIN data set for testing purposes, especially for fixed-format records.