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Changing the physical block size or logical record length of a sequential data set. Creating an edited data set. Printing a sequential data set or a member of a PDS. Creating partitioned output data set from sequential input data set. An example of an IEBGENER program to copy one dataset to another:
Job Control Language (JCL) is a scripting language used on IBM mainframe operating systems to instruct the system on how to run a batch job or start a subsystem. [1] The purpose of JCL is to say which programs to run, using which files or devices [2] for input or output, and at times to also indicate under what conditions to skip a step.
IBM uses the term data set in official documentation as a synonym for file, and direct-access storage device (DASD) for devices with random access to data locations, such as disk drives, as opposed to devices such as tape drives that can only be read sequentially. VSAM records can be of fixed or variable length.
A partitioned data set (PDS) [7] is a data set containing multiple members, each of which holds a separate sub-data set, similar to a directory in other types of file systems. This type of data set is often used to hold load modules (old format bound executable programs), source program libraries (especially Assembler macro definitions), ISPF ...
The program used in the JCL does not actually need to use the files to cause their creation or deletion — the DD DISP=... specification does all the work. Thus a very simple do-nothing program was needed to fill that role. IEFBR14 can thus be used to create or delete a data set using JCL.
That is, Unix programs using fopen() can access an MVS dataset and a user can allocate a Unix file as though it were a dataset, with some [NB 5] restrictions. The Hierarchical File System (HFS) (not to be confused with Apple's Hierarchical File System ) uses a unique type of dataset, while the newer z/OS File System (zFS) (not to be confused ...
Many of the constants and variables contained within a DCB may be left blank (i.e., these default to zero). The OPEN process results in a merge of the constants and variables specified in the DD JCL statement, and the dataset label for existing magnetic tape and direct-access datasets, into the DCB, replacing the zero values with actual, non-zero values.
DOS and Windows file date API and conversion functions (such as INT 21h/AH=2Ah) officially support dates up to 31 December 2099, only (even though the underlying FAT filesystem would theoretically support dates up to 2107). Hence, DOS-based operating systems, as well as applications that convert other formats to the FAT/DOS format, may show ...