Linting

Linting is the automated analysis of code—or, increasingly, any structured output—to flag errors, enforce style rules, and catch problems before they reach production. The term comes from lint, a Unix utility written by Stephen Johnson at Bell Labs in 1978 to catch bugs and portability issues in C programs. The name referred to the small fibers a dryer filter catches: the stuff you don't notice until it accumulates and causes a fire. Today, linters like ESLint, Ruff, and Pylint are standard in every serious software project, running either in an editor or as a gate in CI/CD pipelines that blocks bad code from merging.

Linting is a form of static analysis—examining source code without executing it. What makes it powerful is that it externalizes judgment. Instead of relying on every developer to remember every rule, you encode rules once and enforce them everywhere. Those rules can be advisory, surfacing warnings in an editor, or hard gates that prevent code from deploying until the violation is fixed.