jim

A small terminal text editor written in Go, inspired by vim/kilo. Built for daily use from the shell.

Build

go build -o jim ./cmd

Works on Linux and macOS.

Usage

jim                 # empty buffer [No Name]
jim path/to/file    # open a file

Keybindings

Key	Action
Arrows	Move cursor
Typing	Insert text
Enter	New line
Tab	Insert tab
Backspace	Delete before cursor
Delete	Delete at cursor
Ctrl+S	Save (requires filename from CLI)
Ctrl+N	New empty buffer
Ctrl+T	Cycle status-bar animation
Ctrl+Q / Ctrl+D	Quit (press twice if unsaved)

Status bar

• Left: [+] filename when modified, else padded filename
• Right: Ln N — file line (1-based, by \n), not wrap row
• Far right: animation glyph

Architecture

See specs/spec-ai-v3.md for MVP decisions and docs/spec-editor-viewport.md for viewport contracts.

Tests

go test ./...

Large files

Text is stored in a linked list of gap buffers (1 KiB chunks). Rendering uses a lazy wrap-line cache that only scans far enough to paint the visible viewport — it does not flatten the whole file each keystroke.