using-screenshots

# Taking and Analyzing Screenshots ## Overview You CAN take screenshots by combining the Bash tool with platform-specific screenshot commands. Screenshots are saved as image files, then loaded into your context using the Read tool for visual analysis. ## When to Use Use this skill when I ask you to: - "Take a screenshot" - "Look at my screen" - "Analyze this UI bug visually" - "Review what's currently displayed" - "Capture and examine the interface" ## Quick Reference | Platform | Command | Interactive Selection | | -------- | ---------------------------------------- | -------------------------- | | macOS | `screencapture` | `-i` flag (area selection) | | Linux | `gnome-screenshot`, `scrot`, or `import` | `-a` or `-s` flag | **Standard workflow**: 1. Detect platform with `uname -s` 2. Check for available screenshot tool 3. Capture to `/tmp/screenshot_$(date +%s).png` 4. Use Read tool with the file path 5. Analyze the image 6. Optionally clean up temp file ## Step-by-Step Instructions ### 1. Detect Platform ```bash uname -s ``` - Returns `Darwin` for macOS - Returns `Linux` for Linux ### 2. Check Available Tools **macOS**: `screencapture` is always available (built-in) **Linux**: Check in priority order: ```bash which gnome-screenshot || which scrot || which import || echo "none" ``` Priority order (best compatibility): 1. `gnome-screenshot` - works on both X11 and Wayland 2. `scrot` - lightweight, X11 only 3. `import` - part of ImageMagick ### 3. Capture Screenshot Use timestamped filename to avoid conflicts: **macOS**: ```bash screencapture -i /tmp/screenshot_$(date +%s).png ``` - `-i` enables interactive area selection - User clicks and drags to select region **Linux with gnome-screenshot**: ```bash gnome-screenshot -af /tmp/screenshot_$(date +%s).png ``` - `-a` for area selection - `-f` specifies filename **Linux with scrot**: ```bash scrot -s /tmp/screenshot_$(date +%s).png ``` - `-s` enables selection mode **Linux with import**: ```bash import /tmp/screenshot_$(date +%s).png ``` - Provides crosshair for click-and-drag selection ### 4. Load Image into Context ```bash Read tool: file_path="/tmp/screenshot_12345.png" ``` The Read tool displays images visually. You'll see the screenshot and can analyze it. ### 5. Analyze the Image Once loaded, you can: - Identify UI elements - Spot visual bugs - Review design elements - Read text content - Examine layout issues ### 6. Optional Cleanup ```bash rm /tmp/screenshot_12345.png ``` Only remove if I won't need the file again. ## Handling Missing Tools If no screenshot tool is available on Linux: 1. **Inform me** which tool is missing 2. **Suggest installation**: - Ubuntu/Debian: `sudo apt install gnome-screenshot` - Fedora: `sudo dnf install gnome-screenshot` - Arch: `sudo pacman -S gnome-screenshot` - ImageMagick: `sudo apt install imagemagick` (or equivalent) 3. **Alternative**: Ask user to manually take screenshot and provide path ## Common Mistakes ### ❌ Saying "I cannot take screenshots" **Reality**: You CAN via Bash + screenshot CLI tools ### ❌ Forgetting to use Read tool after capture **Reality**: The screenshot file must be loaded with Read tool to see it ### ❌ Using relative paths **Reality**: Always use absolute paths (`/tmp/...`) for Read tool ### ❌ Not checking for available tools on Linux **Reality**: Must detect which tool is installed before attempting capture ## Example Workflow ``` User: "Take a screenshot and help me debug this UI bug" 1. Check platform: uname -s → Linux 2. Check available tools: which gnome-screenshot → /usr/bin/gnome-screenshot 3. Capture screenshot: gnome-screenshot -af /tmp/screenshot_1729012345.png → User selects area, file saved 4. Load into context: Read: file_path="/tmp/screenshot_1729012345.png" → Image displays visually 5. Analyze: "I can see the button alignment is off. The 'Submit' button is 5px lower than the 'Cancel' button..." 6. Optional cleanup: rm /tmp/screenshot_1729012345.png ```