Learn Pli - 10 Code Examples & CST Typing Practice Test
PLI (Programming Language One) is a procedural, compiled language designed for business and systems programming, particularly for large-scale data processing and legacy IBM mainframe environments.
Learn PLI with Real Code Examples
Updated Nov 21, 2025
Explain
PLI was created to handle structured programming for commercial applications on IBM mainframes.
It combines features from FORTRAN and ALGOL, with strong support for structured control, record handling, and input/output.
It was widely used in banking, insurance, and enterprise resource planning systems due to its reliability and performance on mainframes.
Core Features
Procedures and subroutines
Arrays, tables, and records
Structured loops and conditionals
Built-in file and print handling
Static typing with mainframe-optimized compilation
Basic Concepts Overview
Variables, constants, and data types
Procedures and modular routines
Arrays, records, and tables
Structured control flow: IF, DO, LOOP
Input/output and batch processing
Project Structure
Source/ - PLI source files
Bin/ - compiled object code
Lib/ - mainframe runtime libraries
Docs/ - documentation and specifications
Jobs/ - JCL scripts for batch execution
Building Workflow
Write PLI source files with .pli extension
Define and implement procedures
Compile using mainframe PLI compiler
Submit jobs for batch execution
Verify results and debug as needed
Difficulty Use Cases
Beginner: small data processing scripts
Intermediate: multi-procedure business applications
Advanced: mainframe batch system programming
Expert: maintaining large-scale legacy enterprise applications
Enterprise: mission-critical banking or insurance systems
Comparisons
More structured than early COBOL
Optimized for mainframe batch processing
Less portable than modern languages
Similar purpose as PL/I but IBM-focused
Strong legacy presence in banking and enterprise
Versioning Timeline
1964-1965 - IBM develops PL/I and variants for enterprise
1960s-1970s - PLI widely adopted for mainframe batch systems
1980s - Legacy banking and insurance systems solidified use
1990s-2000s - Integration with modern mainframe technologies
2025 - Maintained in legacy enterprise and educational environments
Glossary
Record: structured data type with fields
Procedure: reusable subroutine
Array/Table: indexed collection of elements
Batch job: program executed in mainframe job queue
JCL: Job Control Language for compiling and running jobs
Frequently Asked Questions about Pli
What is Pli?
PLI (Programming Language One) is a procedural, compiled language designed for business and systems programming, particularly for large-scale data processing and legacy IBM mainframe environments.
What are the primary use cases for Pli?
Large-scale batch processing. Business and financial systems. Mainframe application maintenance. Data processing for enterprises. Legacy system integration and updates
What are the strengths of Pli?
Highly reliable for business-critical applications. Optimized for IBM mainframes. Structured syntax reduces errors. Good for batch and report processing. Supports modular programming with procedures
What are the limitations of Pli?
Mainframe-dependent and outdated for modern platforms. Limited modern tooling or IDE support. Not suitable for web, mobile, or GUI applications. Smaller community compared to modern languages. Steeper learning curve for new programmers
How can I practice Pli typing speed?
CodeSpeedTest offers 10+ real Pli code examples for typing practice. You can measure your WPM, track accuracy, and improve your coding speed with guided exercises.