Skip to content

File Association

Register OctoEdit as a handler for the file types you choose, so double-clicking a .cpp, .md or .log in your file manager opens it here. Everything lives on one Preferences page: Preferences ▸ File Associations.

How it works

The page shows a tree of common file types, grouped by family (C / C++ / Objective-C, JVM & .NET, Web, Scripting, Data & Config, Markup & Docs, Plain text & Logs). Tick a whole language, a whole category, or individual extensions — parents roll up to a partially-checked state.

A Custom node lets you add any extension the catalog doesn't list: type it (with or without the leading dot — cpp, .CPP and .cpp all normalize to .cpp) and press Add.

Press OK / Apply and the plugin registers the selected types with the operating system.

The OS confirms the final default

Modern Windows does not let any application silently make itself the default handler. Applying the page registers OctoEdit as a candidate — it appears in every ticked type's "Open with" list and in the Default apps page. The "Set as default in Windows…" button then deep-links you to the system's Default Apps UI, where you confirm the default yourself. Unticking a type removes the registration again.

On macOS, Launch Services applies the association directly (the system may show a one-time consent prompt).

Platform Support
Windows 10 / 11 Registers per-user (no administrator rights needed) + opens the Default Apps UI.
macOS Sets the default editor role via Launch Services. (Not yet verified on a Mac.)
Linux Not supported yet — the page explains this and stays informational.

Settings

The plugin persists your selection and re-asserts the registrations on each launch (so an OS cleanup or profile migration doesn't silently drop them).

  • Workspace — open a whole folder inside the editor instead.
  • Command line — opening files from a shell, including the file.txt:42 go-to-line syntax.