md2pdf

#!/usr/bin/env sh
# vim: ft=sh ts=4 sw=4 sts=4 et :

# Get absolute path without using realpath/readlink
abs_path() {
    case "$1" in
    /*) printf '%s\n' "$1" ;;
    *) printf '%s/%s\n' "$PWD" "$1" ;;
    esac
}

md2pdf() {
    pandoc \
        --lua-filter="${HOME}/.pandoc/md2pdf_filter.lua" \
        --pdf-engine="$PDF_ENGINE" \
        -V block-headings \
        -V colorlinks=true \
        -V CJKmainfont="Source Han Serif CN" \
        -V geometry:margin=1in \
        -f markdown-implicit_figures \
        -t pdf \
        "$1" \
        -o "${1%.md}.pdf"
}

usage() {
    printf "Usage: %s [OPTIONS] files\n" "$(basename "$0")"
    printf "Options:\n"
    printf "  -l, --lualatex     Use lualatex engine\n"
    printf "  -x, --xelatex      Use xelatex engine\n"
    printf "  -m, --latexmk      Use latexmk engine\n"
    printf "  -w, --wkhtmltopdf  Use wkhtmltopdf engine\n"
    printf "  -p, --pdflatex     Use pdflatex engine (default)\n"
    printf "  --pdf-engine=NAME  Use specified PDF engine\n"
    printf "  -h, --help         Show this help message\n"
}

main() {
    PDF_ENGINE="pdflatex"
    while [ $# -gt 0 ]; do
        case $1 in
        -l | --lualatex)
            PDF_ENGINE="lualatex"
            ;;
        -x | --xelatex)
            PDF_ENGINE="xelatex"
            ;;
        -m | --latexmk)
            PDF_ENGINE="latexmk"
            ;;
        -w | --wkhtmltopdf)
            PDF_ENGINE="wkhtmltopdf"
            ;;
        -p | --pdflatex)
            PDF_ENGINE="pdflatex"
            ;;
        -h | --help | -\?)
            usage
            exit 0
            ;;
        --pdf-engine=*)
            PDF_ENGINE="${1#*=}"
            ;;
        --pdf-engine)
            if [ -z "$2" ]; then
                echo "Error: --pdf-engine requires an argument" >&2
                exit 1
            fi
            PDF_ENGINE="$2"
            shift
            ;;
        --)
            shift
            break
            ;;
        -*)
            echo "Error: unknown option '$1'" >&2
            usage
            exit 1
            ;;
        *)
            break
            ;;
        esac
        shift
    done

    if [ $# -eq 0 ]; then
        echo "Error: no input files" >&2
        usage
        exit 1
    fi

    for file in "$@"; do
        oldpwd=$PWD

        # Pictures in markdown cannot be fetched if we are not in the same
        # directory
        cd "$(dirname "$(realpath "$file")")" >/dev/null 2>&1 || exit 1

        if ! md2pdf "$(basename "$file")"; then
            rc=$?
            echo "md2pdf: error: pandoc failed to convert '$file' with exit code $rc" >&2
            cd "$oldpwd" >/dev/null 2>&1
            exit $rc
        fi

        cd "$oldpwd" >/dev/null 2>&1
    done
}

main "$@"