Multiplex the stdout from a command as the stdin to numerous commands, collect the outputs under command headings in markdown format.

fabric-multiplex.sh

#!/bin/bash

# Pedram Amini
# https://pedramamini.com

run_command() {
    local cmd="$1"
    local input_file="$2"
    local output_file="$3"

    {
        echo "# $cmd"
        fabric --pattern "$cmd" < "$input_file"
        echo  # Add an empty line after each command's output
        echo
    } > "$output_file"
}

multiplex() {
    local tmpfile=$(mktemp)  # Temporary file for input
    local output_files=()    # Array to hold temporary files for outputs

    cat > "$tmpfile"  # Save the stdin to the temporary file

    for cmd in "$@"; do
        local output_file=$(mktemp)  # Create a temporary file for this command's output
        output_files+=("$output_file")  # Store the output file in the array

        run_command "$cmd" "$tmpfile" "$output_file" &
    done

    wait  # Wait for all commands to complete

    # Concatenate and display the outputs in the correct order
    for output_file in "${output_files[@]}"; do
        cat "$output_file"
        rm "$output_file"  # Clean up the output file
    done

    rm "$tmpfile"  # Clean up the input temporary file
}

if [ "$#" -lt 1 ]; then
    echo "Usage: $0 command1 [command2 ...]"
    exit 1
fi

multiplex "$@"