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Languages & runtimes · #rexx
When automating system tasks with REXX, the CALL statement can run any OS command. This article outlines a minimal, secure design: whitelist enforcement, output capture, status checks, and cleanup. It also covers failure modes and when to adjust the design for high‑throughput or cross‑platform use.
Stop fighting with inconsistent regex engines. Learn how Rexx's PARSE instruction uses simple templates to extract text fields consistently across Linux, Windows, and mainframes.
Learn how Rexx’s built‑in list type gives O(1) key lookup, simplifies iteration, and where to watch for memory or compatibility issues.
A diagnostic guide for resolving Syntax Errors and Undefined Variable issues in Rexx, featuring a diagnostic matrix, tracing techniques, and initialization fixes.
Rexx’s built‑in REGEXP function lets you perform POSIX‑style pattern matching without external libraries. Learn how to extract substrings, pre‑compile patterns for speed, and avoid common pitfalls like backtracking and legacy support gaps.
REXX arithmetic precision is governed by NUMERIC DIGITS and equality tolerance by NUMERIC FUZZ. The documented feature is implementation sensitive, with default values and comparison semantics varying between IBM z/OS REXX, Regina, and ooRexx. The goal is to establish a consistent understanding of how significant digit limits and fuzz tolerance affect numeri
We need to guarantee that a REXX restoration script that uses CALL SYSTEM produces the same data integrity results on IBM i, Unix, and Linux. The goal is to detect failures and verify that the restored files match the original backup. CALL SYSTEM executes a native shell command and returns a status code, but the way the status and any command output are expo
Repeatable REXX development requires predictable numeric conversion behavior across implementations. The REXX standard does not definitively specify whether an empty string used in a numeric context should be treated as zero or should trigger a numeric value required condition. This ambiguity affects arithmetic expressions and comparisons and limits repeatab