Quick Capture Without Tape Files

Overview

The snap and capture commands let you record terminal output directly from the command line without creating a tape file. These are ideal for:

  • Quick one-off screenshots of command output
  • CI/CD pipelines generating documentation
  • Scripted generation of terminal visuals

Both commands execute a single shell command and produce SVG output.

Snap Command

Captures a static SVG screenshot of the terminal after your command completes.

Basic Usage

vcr snap "echo Hello World" -o hello.svg

The command waits for your shell command to finish and terminal output to stabilize, then captures the final state.

Example: Documentation Screenshot

vcr snap "dotnet run --project .\Example\ canvas" -o canvas.svg --cols 82 --rows 16

Example: Styled Screenshot

vcr snap "ls -la" -o files.svg --theme "Dracula" --disable-cursor --transparent-background

Capture Command

Records an animated SVG of the entire command execution.

Basic Usage

vcr capture "npm install" -o install.svg

The command records frames while your shell command runs, then renders an animated SVG.

Example: Build Process Recording

vcr capture "dotnet build" -o build.svg --cols 100 --rows 30

Example: Themed Recording

vcr capture "git status && git log --oneline -5" -o git.svg --theme "One Dark" --disable-cursor

Common Options

Both commands support the same options:

Option Description Example
-o, --output Output file path (default: output.svg) -o demo.svg
--theme Terminal color theme --theme "Dracula"
--cols Terminal width in columns --cols 80
--rows Terminal height in rows --rows 24
--font-size Font size in pixels --font-size 18
--disable-cursor Hide the cursor in output --disable-cursor
--transparent-background Use transparent background --transparent-background
--end-buffer Buffer time after last activity --end-buffer 500ms
-v, --verbose Enable verbose logging -v

Theme Examples

# Dracula theme
vcr snap "echo Hello" -o hello.svg --theme "Dracula"
  
# One Dark theme with transparent background
vcr snap "echo Hello" -o hello.svg --theme "One Dark" --transparent-background

Use vcr themes to see all available themes.

When to Use Each

Use Case Command Why
Final output only snap Smaller file, just the result
Show the process capture Animated, shows execution
Documentation images snap Clean, static images
Demo recordings capture Shows real-time behavior
CI/CD screenshots snap Fast, deterministic

Snap vs Capture vs Tape Files

Feature snap capture Tape File
Output Static SVG Animated SVG Any format
Commands Single exec Single exec Multiple commands
Typing simulation No No Yes
Setup required None None Create .tape file
Best for Quick screenshots Quick recordings Complex demos

Use tape files when you need:

  • Simulated typing with Type command
  • Multiple commands with precise timing
  • Complex workflows with Wait, Sleep, Hide/Show
  • Non-SVG output formats (GIF, MP4, WebM)

Troubleshooting

If output captures too early: Use --end-buffer to wait longer after the last output:

vcr snap "slow-command" -o output.svg --end-buffer 2s

If terminal dimensions are wrong: Specify explicit dimensions:

vcr snap "command" -o output.svg --cols 100 --rows 30

If the command fails silently: Add verbose logging to see what's happening:

vcr snap "command" -o output.svg -v
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