15.5.2.1 SORT FIELDS

SORT data: a character string containing an image of the SORT statement. This card image must begin and end with a blank. It will contain the sort criteria and the description of these criteria.

15.5.2.2 RECORD

RECORD information: A character string containing a card image of the RECORD control statement. It too must begin and end with a blank. It describes the length and format of the records.

15.5.2.3 STORAGE

STORAGE information: This will be a FIXED DECIMAL expression indicating the amount of storage available to the sort.

15.5.2.4 RETURN CODE

This will be a FIXED BINARY variable where the sort will place a return code equal to 0 or 16 according to the correct or incorrect result of its execution.

15.5.2.5 E15 EXIT PROCEDURE

The name of the PL/I function procedure to be executed at the sort input exit point is E15. It will pass to the sort one-by-one the records to be sorted. Note that when the sort is called from PL/I, it does not allow merging of records read from SYSIN with records passed from the E15 exit procedure.

15.5.2.6 EXIT E35

Name of the entry point is F35, and name of the PL/I procedure (internal or external) which will receive control after the sort phase.

15.5.2.7 DDNAME PREFIXES

The names of the sort files are defined by default by the sort. The first four characters can be defined by the user:

SORTIN XXXXIN

SORTOUT XXXXOUT

SORTWK01 XXXXWK0I

SORTWK0n XXXXWK0n

SORTCKPT XXXXCKPT

The other files must remain as SYSLIB and SYSOUT. This parameter therefore allows the user to define DDnames convenient to him.

15.5.2.8 SORT MESSAGES

The user can ask for sort messages to be directed to the console operator or to the SYSOUT file, and to specify the severity of the messages:

NO

No messages on SYSOUT

AP

All messages on SYSOUT

AC

All messages to the console

CP

Critical messages on SYSOUT

CC Critical messages on the console

Chapter 15. PL/I 341

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IBM OS/390 manual Sort Fields, Record, Storage, Return Code, Exit E35

OS/390 specifications

IBM OS/390, a versatile operating system, was a cornerstone in enterprise environments and played a pivotal role in mainframe computing. Released in the mid-1990s, OS/390 combined the strengths of IBM's MVS (Multiple Virtual Storage) with new features and enhancements, targeting scalability, reliability, and performance in demanding business applications.

One of the key features of OS/390 was its robust support for multiple users and processes. The system allowed thousands of concurrent users to access applications and data, ensuring high availability and minimizing downtime—a critical requirement for many large organizations. This scalability was supported through various enhancements in memory management and processor scheduling, enabling optimal resource allocation across diverse workloads.

OS/390 was known for its superior workload management capabilities. The Workload Manager (WLM) component allowed administrators to define service policies, specifying how system resources would be allocated according to the priority of tasks. This ensured that critical business processes received the necessary resources while less critical tasks were managed more flexibly.

Another significant characteristic of OS/390 was its commitment to security. The operating system provided comprehensive security features, including user authentication, data encryption, and auditing capabilities. This focus on security was vital for organizations handling sensitive data, ensuring compliance with regulations and safeguarding against unauthorized access.

OS/390 also supported advanced technologies that facilitated integration and development. The system included features like the IBM CICS (Customer Information Control System) for transaction processing and IMS (Information Management System) for database management. These technologies allowed organizations to build robust, high-performance applications tailored to specific business needs.

The ease of network integration was another strength of OS/390. With the advent of the Internet and global connectivity, OS/390 systems could easily interface with various network protocols, enabling businesses to operate in a connected world. This inclusion paved the way for many organizations to expand their capabilities and offer new services, driving digital transformation.

In conclusion, IBM OS/390 represented a significant advancement in mainframe technology, combining scalability, security, and robust workload management. Its rich feature set and support for critical enterprise applications solidified its role as a vital component of many organizations' IT infrastructures, ensuring they could meet their operational challenges head-on while supporting future growth. As technology continues to evolve, the legacy of OS/390 remains influential in the realm of computing.