md-to-html5

#! /bin/sh

HERE=$(cd $(dirname $0); pwd)
THIS=$(basename $0)

# Our HTML5 template, produced from the default pandoc template with some
# massaging by 'mk-pandoc-template'.
template="$HERE/../inc/pandoc-template.html5"

# Use the solarized highlight theme, since that's what we use in the blog
# See https://pandoc.org/MANUAL.html#syntax-highlighting
highlightstyle="$HERE/../inc/pandoc-solarized.theme"

######################################################################
#
#  Option processing
#

output=
index=

shortopts='io:h'
longopts='index,output:,help'
usage="\
Usage 1: $THIS [ options ] [ key=value ... ] < file.md > file
Usage 2: $THIS [ options ] [ key=value ... ] file.md ...

Options:
    -o, --output=PATH           Relative path of the output file
    -i, --index                 Indicates that this is an index file
    -h, --help                  Output this usage and do nothing else

In usage 1, the template is read from standard input and the processing
result is output to the path given by --output.  In this usage, the --output
option is mandatory.

In usage 2, the templates are read from the files given as argument, and
the processing result for each of them is written to a corresponding file
without the '.md' suffix.  All given file names must have the '.md' suffix.
In this usage, the --output option is forbidden.

In both usages, one can also set template variables with the form key=value.
They must come before any file name."

# Standard getopt calling sequence
if ! TEMP=$(getopt -o "$shortopts" --long "$longopts" -n $THIS -- "$@"); then
    echo >&2 "$usage"
    exit 1
fi
eval set -- "$TEMP"
unset TEMP

# Check the parsed options
while true; do
    case "$1" in
	'-o' | '--output' )
	    output="$2"
	    shift 2
	    ;;
	'-i' | '--index' )
	    index=1
	    shift
	    ;;
	'-h' | '--help' )
	    echo >&2 "$usage"
	    exit 0
	    ;;
	'--' )
	    shift
	    break
	    ;;
	* )
	    echo >&2 'Internal error!'
	    echo >&2 "$usage"
	    exit 1
	    ;;
    esac
done

######################################################################
#
#  Main
#

# If there are no other arguments, read from stdin, write to path given with
# --output.  Otherwise, read from the input files and write to corresponding
# output files.
if [ $# -eq 0 ]; then
    if [ -z "$output" ]; then
	echo >&2 'Output path must be set with -o / --output in this mode'
	exit 1
    fi

    if [ "$(basename "$output" .html)" = "$output" ]; then
	echo >&2 'Output path must end with .html'
	exit 1
    fi

    # Set '-' to mean stdin / stdout
    set -- -
elif [ -n "$output" ]; then
    echo >&2 '-o / --output is confusing in this mode'
    exit 1
fi

# Check that all the arguments are existing and correctly named files
errfiles=
nofiles=
for f in "$@"; do
    [ "$f" = "-" ] && continue

    base=$(basename "$f" .md)

    if [ "$base" = "$f" ]; then
	errfiles="$errfiles '$f'"
    elif [ ! -f "$f" ]; then
	nofiles="$nofiles '$f'"
    fi
done
if [ -n "$errfiles" ]; then
    echo >&2 "Files not ending with .md:$errfiles"
fi
if [ -n "$nofiles" ]; then
    echo >&2 "Files no present:$nofiles"
fi
if [ -n "$errfiles" -o -n "$nofiles" ]; then
    exit 1
fi

for f in "$@"; do
    if [ "$f" != "-" ]; then
	base=$(basename "$f" .md)
	dir=$(dirname "$f")

	if [ "$f" = "$base" ]; then
	    continue;
	fi
    else
	base=$(basename "$output" .html)
	dir=$(dirname "$output")
    fi

    if [ "$dir" = "." -o "$dir" = "" ]; then
	title="/$base.html"
	top=""
    else
	title="/$dir/$base.html"
	top=`echo "$dir" | sed -E -e 's|[^/]+|..|g'`/
    fi

    # is it an index file?
    def_isindex=
    if [ -n "$index" -o "$base" = "index" ]; then
	def_isindex="-M is-index=true"
    fi

    (
	# metadata
	meta="$dir/dirdata.yaml"
	if [ -f "$meta" ]; then
	    cat $meta
	fi

	if [ "$f" = "-" ]; then
	    cat
	else
	    cat "$f"
	fi
    ) | (
	cd $dir
	pandoc -t html5 -f markdown --template="$template" \
               --highlight-style="$highlightstyle" \
               --tab-stop=8 --shift-heading-level-by=1 \
               -M author-meta='OpenSSL Foundation, Inc.' \
               -M lang=en \
	       -M pagetitle="$title" \
	       $def_isindex -M top="$top"
    ) | (
	cat > "$dir/$base.html"
    )
done