Documentation
📘 Commands
log

log

rfswift log

Record and replay terminal sessions for documentation and training.

Synopsis 

# Start recording a session
rfswift log start [-o OUTPUT_FILE] [--use-script]

# Stop recording
rfswift log stop

# Replay a recorded session
rfswift log replay -i INPUT_FILE [-s SPEED]

# List recorded sessions
rfswift log list [--dir DIRECTORY]

The log command records RF Swift terminal sessions using asciinema (or the script command as fallback). This is perfect for creating tutorials, documenting workflows, or sharing demonstrations.

Subcommands

log start

Start recording a terminal session.

Options:

Flag Description Default Example
-o, --output STRING Output file path Auto-generated -o my-session.cast
--use-script Force use of script command false --use-script

log stop

Stop the currently active recording session.

No options required.

log replay

Replay a previously recorded session.

Options:

Flag Description Default Example
-i, --input STRING Input file to replay Required -i session.cast
-s, --speed FLOAT Playback speed multiplier 1.0 -s 2.0

log list

List all recorded session files in a directory.

Options:

Flag Description Default Example
--dir STRING Directory to search Current directory --dir ~/recordings

Examples

Basic Usage

Start recording:

rfswift log start
# Recording started: rfswift-session-20240112-143015.cast

Start recording with custom filename:

rfswift log start -o tutorial-wifi-analysis.cast

Stop recording:

rfswift log stop

Replay a session:

rfswift log replay -i tutorial-wifi-analysis.cast

Replay at 2x speed:

rfswift log replay -i tutorial-wifi-analysis.cast -s 2.0

List all recordings:

rfswift log list

List recordings in specific directory:

rfswift log list --dir ~/rfswift-tutorials

Real-World Scenarios

Create a tutorial:

# Start recording
rfswift log start -o sdr-tutorial-basics.cast

# Perform tutorial steps
rfswift run -i penthertz/rfswift_noble:sdr_full -n tutorial
rfswift exec -c tutorial
rtl_test -t
# ... demonstrate features ...
exit

# Stop recording
rfswift log stop

# Replay to verify
rfswift log replay -i sdr-tutorial-basics.cast

Document a bug:

# Record the problem
rfswift log start -o bug-report-issue-123.cast

# Reproduce the issue
rfswift exec -c production
# ... reproduce bug ...
exit

# Stop recording
rfswift log stop

# Share bug-report-issue-123.cast with team

Recording Format

Asciinema Format (.cast)

By default, RF Swift uses asciinema format, which records:

  • Terminal output with timing information
  • Exact keystroke timing
  • Terminal dimensions
  • Environment metadata

Advantages:

  • Compact file size
  • Precise timing reproduction
  • Web-embeddable
  • Editable timing

Example .cast file:

{"version": 2, "width": 120, "height": 30, "timestamp": 1704981234}
[0.123456, "o", "$ rfswift run -i sdr_full -n demo\r\n"]
[1.234567, "o", "Container started: demo\r\n"]

Script Format (Fallback)

When asciinema is not available, RF Swift falls back to the script command:

Use --use-script flag to force:

rfswift log start --use-script -o session.txt

Playback Control

Speed Control 

# Normal speed (1.0x)
rfswift log replay -i session.cast

# Fast playback (2x)
rfswift log replay -i session.cast -s 2.0

# Very fast (3x)
rfswift log replay -i session.cast -s 3.0

# Slow playback (0.5x)
rfswift log replay -i session.cast -s 0.5

# Very slow (0.25x)
rfswift log replay -i session.cast -s 0.25

Interactive Playback

If using asciinema format, you can use asciinema player for interactive control:

# Install asciinema
pip install asciinema

# Play with controls
asciinema play session.cast

# Controls during playback:
# Space - Pause/Resume
# . - Step forward
# Ctrl+C - Exit

Sharing Recordings

Web Embedding (Asciinema) 

# Upload to asciinema.org
asciinema upload session.cast

# Returns URL: https://asciinema.org/a/abc123

# Embed in documentation:
# <script src="https://asciinema.org/a/abc123.js" id="asciicast-abc123" async></script>

Self-Hosting 

# Copy recordings to web server
scp *.cast webserver:/var/www/tutorials/

# Link in documentation
# https://tutorials.example.com/wifi-setup.cast

Distribution 

# Create distribution package
mkdir -p rfswift-training-package
cp ~/recordings/*.cast rfswift-training-package/

# Add README
cat > rfswift-training-package/README.md << 'EOF'
# RF Swift Training Materials

## Lessons
1. basics.cast - RF Swift basics
2. wifi-analysis.cast - WiFi analysis
3. sdr-setup.cast - SDR setup

## Playback
```bash
rfswift log replay -i lesson-name.cast

EOF

Package

tar czf rfswift-training.tar.gz rfswift-training-package/

Distribute

Share rfswift-training.tar.gz with team

Troubleshooting

Recording Not Starting

Problem: rfswift log start fails

Solutions:

# Check if asciinema is installed
which asciinema

# Install asciinema
pip install asciinema
# or
apt-get install asciinema  # Ubuntu/Debian
brew install asciinema      # macOS

# Use script command as fallback
rfswift log start --use-script

Recording File Not Found

Problem: Cannot find recorded file

Solutions:

# Check current directory
ls -la *.cast

# List all recordings
rfswift log list

# Check in home directory
rfswift log list --dir ~

# Find by date
find ~ -name "*.cast" -mtime -1  # Last 24 hours

Replay Not Working

Problem: Cannot replay session

Solutions:

# Check file exists
ls -l session.cast

# Verify file is not corrupted
file session.cast

# Try with asciinema directly
asciinema play session.cast

# Use script format instead
rfswift log start --use-script

Related Commands

  • exec - Execute commands that can be recorded
  • run - Run containers to record
  • last - Show containers for recording sessions
🎬
Perfect for Training: The log command is ideal for creating training materials. Record once, share with your entire team. Students can replay at their own pace with speed control!
Sensitive Information: Recordings capture everything displayed in the terminal, including passwords and API keys if shown. Review recordings before sharing publicly!
Asciinema vs Script: RF Swift prefers asciinema format (.cast) for its precise timing and web-embeddable features. The script command is available as a fallback with --use-script.
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