Convert MIME format wiki export (developed for PhpWiki exports) to Markdown

mime2mdwn

#!/bin/bash

# 
# mime2mdwn - Convert MIME format wiki export (developed for PhpWiki exports) to Markdown
# 

# globals
debug=false

# the actual heavy lifting
function convert_mime_to_markdown() {
	local in_header=true
	local boundary=''
	local version=0
	local data=''
	local data_version=0
	while IFS=$IFS$'\r' read -r line; do
		# process header lines
		if $in_header; then
			# in MIME formatting, a blank line signifies the end of the header
			if [ "$line" = "" ]; then
				if $debug; then printf "DEBUG: EOH\n"; fi
				in_header=false
			else
				if $debug; then printf "DEBUG: HEADER: %s\n" "$line"; fi
				
				# does the line contain a version number?
				if [[ "$line" =~ version=([[:digit:]]+) ]]; then
					version="${BASH_REMATCH[1]}"
					if $debug; then printf "DEBUG: VERSION %s:\n" "$version"; fi
					if (( $version >= $data_version )); then
						data=''
						data_version=$version
					fi
				fi
				# does the line contain a boundary?
				if [[ "$line" =~ boundary=\"(.*)\" ]]; then
					boundary="^--${BASH_REMATCH[1]}(--)?"
					if $debug; then printf "DEBUG: boundary = %s\n" "$boundary"; fi
				fi
			fi
		else
			# is this the beginning of another "part"?
			if [[ "$line" =~ $boundary ]]; then
				in_header=true
			# otherwise, this is "part" content
			else
				if $debug; then printf "%s\n" "DEBUG: $line"; fi
				if (( $version == $data_version )); then
					data="${data}${line}"$'\n'
				fi
			fi
		fi
	done < "$1"
	#printf "DATA (VERSION %s; pre-markup conversion):\n%s" "$data_version" "$data"
	
	# convert CamelCase (starting w/capital; e.g. "NewtonNewbieGuide") to wiki links (e.g. "[[NewtonNewbieGuide]]")
	data=$(echo -n "$data" | perl -pe "s/(^|\b|_)((?<![\[|])[A-Z][a-z]+[A-Z][A-Za-z]+(?![\]|]))($|\b|_)/\1\[\[\2\]\]\3/g")
	
	# convert non-URI links in square brackets (e.g. "[NewtonConnectivityCD]") to wiki links (e.g. "[[NewtonConnectivityCD]]"
	#data=$(echo -n "$data" | sed -E "s/([^[])\[([^\s]+)\]([^]])/\1\[\[\2\]\]\3/g")
	data=$(echo -n "$data" | perl -pe "s/((?<!\[)\[[A-Za-z0-9]+\](?!\]))/\[\1\]/g")
	
	# convert non-URI, named links in square brackets  (e.g. "[BluetoothConnection|UsingBluetoothIndex]") to Markdown link format (e.g. "[BluetoothConnection](/UsingBluetoothIndex)")
	data=$(echo -n "$data" | perl -pe "s/(?<!\[)\[(.+)\s?\|\s?([A-Za-z0-9]+)\](?!\])/[\1](\2)/g")
	
	# convert URI, named links in square brackets (e.g. "[Newtontalk.net|http://www.newtontalk.net/]") to Markdown link format (e.g. "[Newtontalk.net](http://www.newtontalk.net/)")
	data=$(echo -n "$data" | perl -pe "s/(?<!\[)\[(.+)\s?\|\s?([A-Za-z]+:(\/\/)?.+)\](?!\])/[\1](\2)/g")
	
	# convert URI-only links in square brackets (e.g. "[http://tools.unna.org/glossary/]") to angle bracket format (e.g. "<http://tools.unna.org/glossary/>")
	data=$(echo -n "$data" | perl -pe "s/(?<!\[)\[([A-Z-a-z]+:(\/\/)?.+)\](?!\])/<\1>/g")
	
	# convert triple prime bold (e.g. "'''bold'''") to Markdown format (e.g. "__bold__")
	data=$(echo -n "$data" | perl -pe "s/(?<!')'''(.+)'''(?!')/__\1__/g")
	
	# convert double prime emphasis (e.g. "''emphasis''") to Markdown format (e.g. "_emphasis_")
	data=$(echo -n "$data" | perl -pe "s/(?<!')''(.+)''(?!')/_\1_/g")
	
	# convert headings (e.g. "!!Heading") to Markdown atk-style format (e.g. "## Heading")
	data=$(echo -n "$data" | perl -pe "s/^!{1}([^!]+)$/# \1/g")
	data=$(echo -n "$data" | perl -pe "s/^!{2}([^!]+)$/## \1/g")
	data=$(echo -n "$data" | perl -pe "s/^!{3}([^!]+)$/### \1/g")
	data=$(echo -n "$data" | perl -pe "s/^!{4}([^!]+)$/#### \1/g")
	data=$(echo -n "$data" | perl -pe "s/^!{5}([^!]+)$/##### \1/g")
	data=$(echo -n "$data" | perl -pe "s/^!{6}([^!]+)$/###### \1/g")
	
	# printf "DATA (VERSION %s; post-markup conversion):\n%s" "$data_version" "$data"
	
	# write the data back out to the file
	echo -n "$data" > "$1"
}

# batch process a directory of files?
if [ -d "$1" ]; then
	for file in $1/*; do
		if [ ! -d "$file" ]; then
			convert_mime_to_markdown "$file"
		fi
	done
# or just a single file?
elif [ -e "$1" ]; then
	convert_mime_to_markdown "$1"
# if no file/directory, throw an error
else
	printf "ERROR! %s not found!\n" "$1"
fi