ComfyUI RB Command

Execute shell commands/scripts with dynamic inputs, and result caching. Supports placeholders ({input0}, {seed}) and environment variables ($INPUT_0, $SEED, etc.).

Features

• Command Execution: Run arbitrary shell commands and scripts via /bin/bash (configurable)
• Dynamic Input Slots: Automatically expand input slots on connection (up to 20), supporting images, audio, video, text, and more
• Placeholder Substitution: Use {input0}, {input1}, {seed}, {input_image_count}, {input_video_count}, {input_audio_count} placeholders in commands to reference inputs and counts
• Environment Variables: Access parameters via $INPUT_0, $INPUT_1, $SEED, $INPUT_COUNT, $INPUT_ALL, $INPUT_IMAGE_COUNT, $INPUT_VIDEO_COUNT, $INPUT_AUDIO_COUNT
• Timeout Protection: Configurable timeout (1-3600 seconds), auto-terminates on timeout
• Separate Outputs: stdout, stderr, and exit code are returned as distinct outputs for flexible workflow routing

Installation

cd ComfyUI/custom_nodes/
git clone https://github.com/itribs/comfyui-rb-command.git
pip install -r requirements.txt

Parameters

Required

Parameter	Type	Default	Description
command	STRING (multiline)	echo input: {input0} seed: {seed}	Shell command to execute, supports placeholders
seed	INT	0	Random seed, accessible via {seed} or $SEED
working_dir	STRING	current working directory	Working directory for command execution
executable	STRING	/bin/bash	Shell interpreter to use
timeout	INT	30	Timeout in seconds (1-3600)

Optional (Dynamic Input Slots)

Parameter	Type	Description
input_0	* (any type)	First input slot. Connecting triggers input_1, and so on, up to 20 slots

Outputs

Output	Type	Description
stdout	STRING	Standard output from the command
stderr	STRING	Standard error from the command
exit_code	INT	Exit code (0 = success, non-zero = error)

Placeholder Syntax

Use the following placeholders in the command field:

Placeholder	Description
{input0}, {input1}, ...	Replaced with the corresponding input slot value (paths are auto-quoted for spaces)
{input_count}	Replaced with the number of connected input slots
{input_image_count}	Number of image inputs
{input_video_count}	Number of video inputs
{input_audio_count}	Number of audio inputs
{input_all}	All input paths (auto-quoted, suitable for bash array expansion)
{seed}	Replaced with the seed value

Examples:

# Merge two videos with ffmpeg
ffmpeg -i {input0} -i {input1} -filter_complex "[0:v][1:v]hstack" output.mp4

# Resize image with ImageMagick
convert {input0} -resize 512x512 -quality 90 output.jpg

# Call a Python script
python3 /path/to/script.py --input {input0} --seed {seed}

# Batch process all inputs via bash array
arr=({input_all})
for f in "${arr[@]}"; do
    echo "Processing: $f"
    convert "$f" -resize 256x256 "${f%.*}_thumb.png"
done

# Conditional logic based on input counts
if [ "$INPUT_IMAGE_COUNT" -gt 0 ]; then
    echo "Processing ${INPUT_IMAGE_COUNT} images, ${INPUT_VIDEO_COUNT} videos, ${INPUT_AUDIO_COUNT} audio files"
fi

Environment Variables

The following environment variables are available during command execution:

Variable	Description
$INPUT_0, $INPUT_1, ...	File path of the corresponding input slot
$SEED	Seed value
$INPUT_COUNT	Number of connected input slots
$INPUT_IMAGE_COUNT	Number of image inputs
$INPUT_VIDEO_COUNT	Number of video inputs
$INPUT_AUDIO_COUNT	Number of audio inputs
$INPUT_ALL	All input paths (auto-quoted, suitable for bash array expansion)

Example:

# Batch process all inputs via bash array (handles spaces, quotes, newlines correctly)
eval "arr=($INPUT_ALL)"
for f in "${arr[@]}"; do
    echo "Processing: $f"
    convert "$f" -resize 256x256 "${f%.*}_thumb.png"
done

Supported Input Types

The node accepts the following ComfyUI data types and converts them for use in commands:

Type	Handling
Image	Converted to temporary PNG file
Video	Converted to temporary MP4 file
Audio	Converted to temporary WAV file
Text (str, int, float, bool)	Converted to string representation

License

MIT License