# LogViewer

**Repository Path**: PhiloKun/LogViewer

## Basic Information

- **Project Name**: LogViewer
- **Description**: A fast, lightweight desktop log viewer with syntax highlighting, built with Electron
- **Primary Language**: Unknown
- **License**: Not specified
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2026-07-04
- **Last Updated**: 2026-07-04

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

# LogViewer

A fast, lightweight desktop log viewer built with Electron. Designed for developers and ops teams who need to browse, search, and analyze large log files with syntax highlighting. Supports **English and Chinese** with one-click switching.

![LogViewer English](screenshot.png) | ![LogViewer Chinese](screenshot-zh.png)
--- | ---
*English* | *中文*

## Features

- **中/EN language switch** — Toggle between English and Chinese with a single click; your preference is saved
- **Syntax highlighting** — Timestamps, log levels (TRACE/DEBUG/INFO/WARN/ERROR/FATAL), URLs, numbers, strings, stack traces, and file paths are color-coded for quick scanning
- **Dark + Light theme** — Toggle between themes with `Ctrl+D` or the theme button; your preference is saved
- **Full-text search** — Search through logs with `Ctrl+F`, navigate matches with `Enter` / `Shift+Enter`
- **Drag & drop** — Drop any text file onto the window, or click "Open" / press `Ctrl+O`
- **Large file support** — Reads files in 4 MB chunks with chunked rendering for files > 50K lines
- **Error/fatal line highlighting** — ERROR and FATAL lines get a tinted background for instant visual recognition
- **Single instance lock** — Only one instance runs; subsequent file opens are routed to the existing window
- **Scroll shortcuts** — `Ctrl+Home` (top), `Ctrl+End` (bottom)
- **Keyboard shortcut reference** — Press `Ctrl+/` to view all shortcuts

## Supported file types

`.log`, `.txt`, `.out`, `.json`, `.csv`, `.md`, `.xml`, `.yaml`, `.yml`, `.cfg`, `.conf`, `.ini`

## Installation

### Download (pre-built)

Download the latest installer or portable executable from the [Releases](https://github.com/PhiloKun/LogViewer/releases) page.

### Build from source

```bash
# Prerequisites: Node.js 18+ and npm

git clone https://github.com/PhiloKun/LogViewer.git
cd LogViewer
npm install

# Run in development mode
npm start

# Build for Windows (installer + portable)
npm run build
```

## Usage

| Action | Shortcut |
|--------|----------|
| Open file | `Ctrl+O` |
| Search | `Ctrl+F` |
| Next match | `Enter` |
| Previous match | `Shift+Enter` |
| Clear search | `Escape` |
| Toggle theme | `Ctrl+D` |
| Toggle language | Click `中`/EN button in toolbar |
| Scroll to top | `Ctrl+Home` |
| Scroll to bottom | `Ctrl+End` |
| Shortcuts help | `Ctrl+/` |

You can also drag and drop files directly onto the window, or click the `Open` button in the top bar.

## Project structure

```
LogViewer/
├── main.js              # Electron main process
├── preload.js           # Preload script (context bridge)
├── log-viewer.html      # Renderer UI + application logic
├── sample.log           # Sample log file for testing
├── screenshot.png       # App screenshot (English)
├── screenshot-zh.png    # App screenshot (Chinese)
├── build-resources/     # App icons (icon.ico, icon.png)
└── package.json         # Project metadata and build configuration
```

## Technical details

- **Frontend:** Vanilla JavaScript, no framework dependency
- **Syntax parser:** Lightweight regex-based highlighting (no heavy dependencies)
- **Backend:** Electron 36 with `contextIsolation: true` for security
- **IPC:** Secured via preload script with `contextBridge`
- **i18n:** Lightweight inline translations via `data-i18n` attributes
- **Large file handling:** Chunked FileReader (browser) / streaming `fs.readFileSync` (Electron IPC)

## License

MIT