Mode:
Duration:
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Coding works best on desktop or with an external keyboard.
PL/I Substring Example - Pli-mainframe Typing CST Test
PL/I Substring Example — Pli-mainframe Code
Extract a substring from a string variable.
SUBSTRING-EX: PROCEDURE;
DECLARE STR CHAR(20) INIT('PL/I Programming');
DECLARE SUB CHAR(10);
SUB = SUBSTR(STR, 1, 3);
PUT SKIP LIST('Substring: ', SUB);
END SUBSTRING-EX;Pli-mainframe Language Guide
PLI (Programming Language One) Mainframe is a procedural programming language primarily used on IBM mainframe systems for business and administrative applications. It emphasizes structured, readable code for transaction processing, batch jobs, and legacy enterprise systems.
Primary Use Cases
- ▸Batch processing of financial transactions
- ▸Payroll and accounting applications
- ▸Report generation and data summarization
- ▸Legacy system maintenance and modernization
- ▸Integration with mainframe DB2, CICS, or IMS systems
Notable Features
- ▸Structured, readable procedural programming
- ▸Strong support for arrays, records, and tables
- ▸Mainframe I/O handling (sequential, indexed, VSAM files)
- ▸Integration with legacy databases like DB2
- ▸Compatibility with IBM batch and transaction processing environments
Origin & Creator
PLI was developed by IBM in the 1960s as a high-level, business-oriented programming language for mainframes, to simplify COBOL-style development with structured programming features.
Industrial Note
Crucial for organizations with legacy mainframe infrastructure, high-volume transaction processing, and systems requiring extreme reliability and uptime.
Quick Explain
- ▸PLI Mainframe was designed for business applications, handling large-scale data processing and transaction management.
- ▸It supports structured programming constructs such as IF statements, loops, and modular subroutines.
- ▸Commonly used on IBM z/OS systems with batch processing, report generation, and financial computation workloads.
- ▸Integrates with mainframe databases like VSAM and DB2, and supports file-based and transaction-based I/O.
- ▸Widely adopted in banking, insurance, and government sectors for stable, long-lived enterprise applications.
Core Features
- ▸Procedural control structures: IF, DO, PERFORM, LOOP
- ▸Subroutine and modular programming support
- ▸File handling for sequential, indexed, and relative files
- ▸Data types optimized for business calculations
- ▸Integration with mainframe transaction monitors and schedulers
Learning Path
- ▸Learn basic PLI syntax and control structures
- ▸Practice dataset I/O (VSAM, sequential files)
- ▸Understand batch processing on mainframe
- ▸Integrate with DB2 and CICS
- ▸Develop modular programs with subroutines and copybooks
Practical Examples
- ▸Generate monthly payroll reports from employee data
- ▸Process bank transactions overnight using batch jobs
- ▸Read VSAM files, apply calculations, and output summaries
- ▸Integrate with DB2 to update account balances
- ▸Schedule recurring batch jobs via JCL for automation
Comparisons
- ▸PLI vs COBOL: more structured, similar mainframe focus
- ▸PLI vs modern languages: less flexible for GUI/web
- ▸PLI vs Rexx: PLI for heavy batch, Rexx for scripting/automation
- ▸PLI vs Java on mainframe: PLI optimized for legacy batch processing
- ▸PLI vs Python/ETL tools: modern alternatives for data pipelines, but not always mainframe-compatible
Strengths
- ▸Highly reliable for large-scale batch processing
- ▸Optimized for IBM mainframe environments
- ▸Mature language with decades of enterprise use
- ▸Structured programming ensures maintainable code
- ▸Strong integration with existing mainframe tools
Limitations
- ▸Limited modern GUI and web integration
- ▸Declining community and fewer new developers
- ▸Less flexible for object-oriented or modern programming paradigms
- ▸Dependency on legacy mainframe infrastructure
- ▸Debugging tools may be less intuitive compared to modern IDEs
When NOT to Use
- ▸If modern object-oriented or web-based applications are needed
- ▸For cloud-native or cross-platform development
- ▸If mainframe infrastructure is unavailable
- ▸For small-scale, non-critical scripts where modern scripting suffices
- ▸When large talent pool and community support is needed
Cheat Sheet
- ▸DCL - declare variables
- ▸DS - define data structures
- ▸IF/ELSE - conditional logic
- ▸DO/LOOP - iteration
- ▸CALL - invoke subroutine
FAQ
- ▸Is PLI still used? -> Yes, mostly in legacy mainframe systems.
- ▸Can I integrate PLI with modern systems? -> Possible via connectors, MQ, or APIs.
- ▸Do I need mainframe access to learn PLI? -> Yes, practical learning requires mainframe or emulator.
- ▸Is PLI procedural or object-oriented? -> Procedural.
- ▸Are there modern alternatives? -> COBOL, Java on mainframe, or ETL/data tools.
30-Day Skill Plan
- ▸Week 1: PLI syntax and basic programs
- ▸Week 2: File I/O and dataset handling
- ▸Week 3: Subroutines and modularization
- ▸Week 4: Integration with DB2 and batch jobs
- ▸Week 5: Optimize batch processing and mainframe performance
Final Summary
- ▸PLI Mainframe is a procedural language for IBM mainframe business applications.
- ▸Optimized for batch processing, report generation, and transaction systems.
- ▸Supports structured programming, modular subroutines, and dataset I/O.
- ▸Widely used in banking, insurance, and government sectors.
- ▸Essential for maintaining legacy mainframe systems and high-reliability workloads.
Project Structure
- ▸Source libraries (PL1) for program code
- ▸Copybooks for reusable data structures
- ▸Load libraries for compiled modules
- ▸JCL scripts for batch execution
- ▸Documentation and test datasets
Monetization
- ▸Enterprise legacy system maintenance
- ▸Banking and financial transaction processing
- ▸Payroll and government data processing
- ▸Mainframe consulting and modernization services
- ▸Integration services for legacy-to-modern systems
Productivity Tips
- ▸Use copybooks for reusable data structures
- ▸Optimize dataset access patterns
- ▸Modularize code with subroutines
- ▸Schedule batch jobs for off-peak hours
- ▸Document workflows and JCL for clarity
Basic Concepts
- ▸Program - self-contained PLI code unit
- ▸Subroutine - reusable modular code
- ▸Dataset - mainframe file (sequential, VSAM, or DB2)
- ▸Compiler - converts PLI source to executable load module
- ▸Job Control Language (JCL) - schedules batch program execution
Official Docs
- ▸https://www.ibm.com/docs/en/pli
- ▸IBM Redbooks on PLI and mainframe programming
- ▸z/OS Programming documentation