greeker.sh

#!/bin/bash

# Function to print usage information
print_usage() {
    echo "Usage: $0 input_file [output_file] [--pdf]"
    echo "Example: $0 input.txt output.md"
    echo "Optional: Use '--pdf' flag to also convert the output to a PDF file."
    echo "Example: $0 input.txt output.md --pdf"
}

# Check if input file is provided
if [[ $# -lt 1 || "$1" == "--help" || "$1" == "-h" ]]; then
    print_usage
    exit 0
fi

input_file="$1"
output_file="${2:-${input_file%.*}_converted.md}"
convert_to_pdf_flag=false

# Check if the --pdf flag is set
if [[ "$#" -eq 3 && "$3" == "--pdf" ]]; then
    convert_to_pdf_flag=true
elif [[ "$#" -gt 3 ]]; then
    print_usage
    exit 1
fi

# Check if input file exists and is readable
if [ ! -r "$input_file" ]; then
    echo "Error: Input file '$input_file' not found or not readable."
    exit 1
fi

# Define a function to perform replacements
replace_greek_and_cyrillic_letters() {
    sed -e 's/Α/\Α/g' \
        -e 's/α/\α/g' \
        -e 's/Β/\Β/g' \
        -e 's/β/\β/g' \
        -e 's/Γ/\Γ/g' \
        -e 's/γ/\γ/g' \
        -e 's/Δ/\Δ/g' \
        -e 's/δ/\δ/g' \
        -e 's/Ε/\Ε/g' \
        -e 's/ε/\ε/g' \
        -e 's/Ζ/\Ζ/g' \
        -e 's/ζ/\ζ/g' \
        -e 's/Η/\Η/g' \
        -e 's/η/\η/g' \
        -e 's/Θ/\Θ/g' \
        -e 's/θ/\θ/g' \
        -e 's/Ι/\Ι/g' \
        -e 's/ι/\ι/g' \
        -e 's/Κ/\Κ/g' \
        -e 's/κ/\κ/g' \
        -e 's/Λ/\Λ/g' \
        -e 's/λ/\λ/g' \
        -e 's/Μ/\Μ/g' \
        -e 's/μ/\μ/g' \
        -e 's/Ν/\Ν/g' \
        -e 's/ν/\ν/g' \
        -e 's/Ξ/\Ξ/g' \
        -e 's/ξ/\ξ/g' \
        -e 's/Ο/\Ο/g' \
        -e 's/ο/\ο/g' \
        -e 's/Π/\Π/g' \
        -e 's/π/\π/g' \
        -e 's/Ρ/\Ρ/g' \
        -e 's/ρ/\ρ/g' \
        -e 's/Σ/\Σ/g' \
        -e 's/σ/\σ/g' \
        -e 's/ς/\σ/g' \
        -e 's/Τ/\Τ/g' \
        -e 's/τ/\τ/g' \
        -e 's/Υ/\Υ/g' \
        -e 's/υ/\υ/g' \
        -e 's/Φ/\Φ/g' \
        -e 's/φ/\φ/g' \
        -e 's/Χ/\Χ/g' \
        -e 's/χ/\χ/g' \
        -e 's/Ψ/\Ψ/g' \
        -e 's/ψ/\ψ/g' \
        -e 's/Ω/\Ω/g' \
        -e 's/ω/\ω/g' \
        -e 's/А/\А/g' \
        -e 's/Б/\Б/g' \
        -e 's/В/\В/g' \
        -e 's/Г/\Г/g' \
        -e 's/Д/\Д/g' \
        -e 's/Е/\Е/g' \
        -e 's/Ё/\Ё/g' \
        -e 's/Ж/\Ж/g' \
        -e 's/З/\З/g' \
        -e 's/И/\И/g' \
        -e 's/Й/\Й/g' \
        -e 's/К/\К/g' \
        -e 's/Л/\Л/g' \
        -e 's/М/\М/g' \
        -e 's/Н/\Н/g' \
        -e 's/О/\О/g' \
        -e 's/П/\П/g' \
        -e 's/Р/\Р/g' \
        -e 's/С/\С/g' \
        -e 's/Т/\Т/g' \
        -e 's/У/\У/g' \
        -e 's/Ф/\Ф/g' \
        -e 's/Х/\Х/g' \
        -e 's/Ц/\Ц/g' \
        -e 's/Ч/\Ч/g' \
        -e 's/Ш/\Ш/g' \
        -e 's/Щ/\Щ/g' \
        -e 's/Ъ/\Ъ/g' \
        -e 's/Ы/\Ы/g' \
        -e 's/Ь/\Ь/g' \
        -e 's/Э/\Э/g' \
        -e 's/Ю/\Ю/g' \
        -e 's/Я/\Я/g' \
        -e 's/а/\а/g' \
        -e 's/б/\б/g' \
        -e 's/в/\в/g' \
        -e 's/г/\г/g' \
        -e 's/д/\д/g' \
        -e 's/е/\е/g' \
        -e 's/ё/\ё/g' \
        -e 's/ж/\ж/g' \
        -e 's/з/\з/g' \
        -e 's/и/\и/g' \
        -e 's/й/\й/g' \
        -e 's/к/\к/g' \
        -e 's/л/\л/g' \
        -e 's/м/\м/g' \
        -e 's/н/\н/g' \
        -e 's/о/\о/g' \
        -e 's/п/\п/g' \
        -e 's/р/\р/g' \
        -e 's/с/\с/g' \
        -e 's/т/\т/g' \
        -e 's/у/\у/g' \
        -e 's/ф/\ф/g' \
        -e 's/х/\х/g' \
        -e 's/ц/\ц/g' \
        -e 's/ч/\ч/g' \
        -e 's/ш/\ш/g' \
        -e 's/щ/\щ/g' \
        -e 's/ъ/\ъ/g' \
        -e 's/ы/\ы/g' \
        -e 's/ь/\ь/g' \
        -e 's/э/\э/g' \
        -e 's/ю/\ю/g' \
        -e 's/я/\я/g'
}

# Function to convert Markdown to PDF
convert_to_pdf() {
    local input_file="$1"
    local output_file="${input_file%.md}.pdf"
    if command -v pandoc >/dev/null 2>&1; then
        pandoc "$input_file" -o "$output_file" --pdf-engine=xelatex -V mainfont="FreeSerif"
        echo "PDF conversion complete. Output saved to '$output_file'"
    else
        echo "Pandoc is not installed. Please install pandoc to use the PDF conversion feature."
    fi
}

# Perform replacements and save output to the specified or default file
replace_greek_and_cyrillic_letters < "$input_file" > "$output_file"

echo "Conversion complete. Output saved to '$output_file'"

# Convert to PDF if the flag is set
if [ "$convert_to_pdf_flag" = true ]; then
    convert_to_pdf "$output_file"
fi