Epub: only attach images referenced in the text.
[librarian.git] / librarian / epub.py
index 2f7bbec..be9488a 100644 (file)
@@ -3,44 +3,94 @@
 # This file is part of Librarian, licensed under GNU Affero GPLv3 or later.
 # Copyright © Fundacja Nowoczesna Polska. See NOTICE for more information.
 #
-from __future__ import with_statement
+from __future__ import print_function, unicode_literals
 
 import os
 import os.path
 import re
 import subprocess
-from StringIO import StringIO
+from six import BytesIO
 from copy import deepcopy
+from mimetypes import guess_type
+
 from lxml import etree
 import zipfile
 from tempfile import mkdtemp, NamedTemporaryFile
 from shutil import rmtree
 
-from librarian import RDFNS, WLNS, NCXNS, OPFNS, XHTMLNS, OutputFile
-from librarian.cover import DefaultEbookCover
+from librarian import RDFNS, WLNS, NCXNS, OPFNS, XHTMLNS, DCNS, OutputFile
+from librarian.cover import make_cover
 
 from librarian import functions, get_resource
 
+from librarian.hyphenator import Hyphenator
+
 functions.reg_person_name()
 functions.reg_lang_code_3to2()
 
 
+def squeeze_whitespace(s):
+    return re.sub(b'\\s+', b' ', s)
+
+
+def set_hyph_language(source_tree):
+    def get_short_lng_code(text):
+        result = ''
+        text = ''.join(text)
+        with open(get_resource('res/ISO-639-2_8859-1.txt'), 'rb') as f:
+            for line in f.read().decode('latin1').split('\n'):
+                list = line.strip().split('|')
+                if list[0] == text:
+                    result = list[2]
+        if result == '':
+            return text
+        else:
+            return result
+    bibl_lng = etree.XPath('//dc:language//text()',
+                           namespaces={'dc': str(DCNS)})(source_tree)
+    short_lng = get_short_lng_code(bibl_lng[0])
+    try:
+        return Hyphenator(get_resource('res/hyph-dictionaries/hyph_' +
+                                       short_lng + '.dic'))
+    except:
+        pass
+
+
+def hyphenate_and_fix_conjunctions(source_tree, hyph):
+    texts = etree.XPath('/utwor/*[2]//text()')(source_tree)
+    for t in texts:
+        parent = t.getparent()
+        if hyph is not None:
+            newt = ''
+            wlist = re.compile(r'\w+|[^\w]', re.UNICODE).findall(t)
+            for w in wlist:
+                newt += hyph.inserted(w, u'\u00AD')
+        else:
+            newt = t
+        newt = re.sub(r'(?<=\s\w)\s+', u'\u00A0', newt)
+        if t.is_text:
+            parent.text = newt
+        elif t.is_tail:
+            parent.tail = newt
+
+
 def inner_xml(node):
     """ returns node's text and children as a string
 
-    >>> print inner_xml(etree.fromstring('<a>x<b>y</b>z</a>'))
+    >>> print(inner_xml(etree.fromstring('<a>x<b>y</b>z</a>')))
     x<b>y</b>z
     """
 
     nt = node.text if node.text is not None else ''
-    return ''.join([nt] + [etree.tostring(child) for child in node])
+    return ''.join([nt] + [etree.tostring(child, encoding='unicode') for child in node])
+
 
 def set_inner_xml(node, text):
     """ sets node's text and children from a string
 
     >>> e = etree.fromstring('<a>b<b>x</b>x</a>')
     >>> set_inner_xml(e, 'x<b>y</b>z')
-    >>> print etree.tostring(e)
+    >>> print(etree.tostring(e, encoding='unicode'))
     <a>x<b>y</b>z</a>
     """
 
@@ -52,7 +102,7 @@ def set_inner_xml(node, text):
 def node_name(node):
     """ Find out a node's name
 
-    >>> print node_name(etree.fromstring('<a>X<b>Y</b>Z</a>'))
+    >>> print(node_name(etree.fromstring('<a>X<b>Y</b>Z</a>')))
     XYZ
     """
 
@@ -67,11 +117,13 @@ def node_name(node):
     return tempnode.text
 
 
-def xslt(xml, sheet):
+def xslt(xml, sheet, **kwargs):
     if isinstance(xml, etree._Element):
         xml = etree.ElementTree(xml)
     with open(sheet) as xsltf:
-        return xml.xslt(etree.parse(xsltf))
+        transform = etree.XSLT(etree.parse(xsltf))
+        params = dict((key, transform.strparam(value)) for key, value in kwargs.items())
+        return transform(xml, **params)
 
 
 def replace_characters(node):
@@ -98,7 +150,7 @@ def find_annotations(annotations, source, part_no):
     for child in source:
         if child.tag in ('pe', 'pa', 'pt', 'pr'):
             annotation = deepcopy(child)
-            number = str(len(annotations)+1)
+            number = str(len(annotations) + 1)
             annotation.set('number', number)
             annotation.set('part', str(part_no))
             annotation.tail = ''
@@ -120,10 +172,10 @@ class Stanza(object):
 
     >>> s = etree.fromstring("<strofa>a <b>c</b> <b>c</b>/\\nb<x>x/\\ny</x>c/ \\nd</strofa>")
     >>> Stanza(s).versify()
-    >>> print etree.tostring(s)
-    <strofa><wers_normalny>a <b>c</b> <b>c</b></wers_normalny><wers_normalny>b<x>x/
+    >>> print(etree.tostring(s, encoding='unicode'))
+    <strofa><wers_normalny>a <b>c</b><b>c</b></wers_normalny><wers_normalny>b<x>x/
     y</x>c</wers_normalny><wers_normalny>d</wers_normalny></strofa>
-    
+
     """
     def __init__(self, stanza_elem):
         self.stanza = stanza_elem
@@ -138,7 +190,7 @@ class Stanza(object):
         tail = self.stanza.tail
         self.stanza.clear()
         self.stanza.tail = tail
-        self.stanza.extend(self.verses)
+        self.stanza.extend(verse for verse in self.verses if verse.text or len(verse) > 0)
 
     def open_normal_verse(self):
         self.open_verse = self.stanza.makeelement("wers_normalny")
@@ -155,6 +207,8 @@ class Stanza(object):
         for i, verse_text in enumerate(re.split(r"/\s*\n", text)):
             if i:
                 self.open_normal_verse()
+            if not verse_text.strip():
+                continue
             verse = self.get_open_verse()
             if len(verse):
                 verse[-1].tail = (verse[-1].tail or "") + verse_text
@@ -185,18 +239,17 @@ def add_to_manifest(manifest, partno):
     """ Adds a node to the manifest section in content.opf file """
 
     partstr = 'part%d' % partno
-    e = manifest.makeelement(OPFNS('item'), attrib={
-                                 'id': partstr,
-                                 'href': partstr + '.html',
-                                 'media-type': 'application/xhtml+xml',
-                             })
+    e = manifest.makeelement(
+        OPFNS('item'), attrib={'id': partstr, 'href': partstr + '.html',
+                               'media-type': 'application/xhtml+xml'}
+    )
     manifest.append(e)
 
 
 def add_to_spine(spine, partno):
     """ Adds a node to the spine section in content.opf file """
 
-    e = spine.makeelement(OPFNS('itemref'), attrib={'idref': 'part%d' % partno});
+    e = spine.makeelement(OPFNS('itemref'), attrib={'idref': 'part%d' % partno})
     spine.append(e)
 
 
@@ -210,7 +263,7 @@ class TOC(object):
     def add(self, name, part_href, level=0, is_part=True, index=None):
         assert level == 0 or index is None
         if level > 0 and self.children:
-            return self.children[-1].add(name, part_href, level-1, is_part)
+            return self.children[-1].add(name, part_href, level - 1, is_part)
         else:
             t = TOC(name)
             t.part_href = part_href
@@ -248,7 +301,10 @@ class TOC(object):
 
             nav_label = nav_map.makeelement(NCXNS('navLabel'))
             text = nav_map.makeelement(NCXNS('text'))
-            text.text = child.name
+            if child.name is not None:
+                text.text = re.sub(r'\n', ' ', child.name)
+            else:
+                text.text = child.name
             nav_label.append(text)
             nav_point.append(nav_label)
 
@@ -265,12 +321,12 @@ class TOC(object):
             texts.append(
                 "<div style='margin-left:%dem;'><a href='%s'>%s</a></div>" %
                 (depth, child.href(), child.name))
-            texts.append(child.html_part(depth+1))
+            texts.append(child.html_part(depth + 1))
         return "\n".join(texts)
 
     def html(self):
-        with open(get_resource('epub/toc.html')) as f:
-            t = unicode(f.read(), 'utf-8')
+        with open(get_resource('epub/toc.html'), 'rb') as f:
+            t = f.read().decode('utf-8')
         return t % self.html_part()
 
 
@@ -288,21 +344,44 @@ def chop(main_text):
     # prepare a container for each chunk
     part_xml = etree.Element('utwor')
     etree.SubElement(part_xml, 'master')
-    main_xml_part = part_xml[0] # master
+    main_xml_part = part_xml[0]  # master
 
     last_node_part = False
+
+    # the below loop are workaround for a problem with epubs in drama ebooks without acts
+    is_scene = False
+    is_act = False
     for one_part in main_text:
         name = one_part.tag
-        if name == 'naglowek_czesc':
-            yield part_xml
-            last_node_part = True
-            main_xml_part[:] = [deepcopy(one_part)]
-        elif not last_node_part and name in ("naglowek_rozdzial", "naglowek_akt", "srodtytul"):
-            yield part_xml
-            main_xml_part[:] = [deepcopy(one_part)]
+        if name == 'naglowek_scena':
+            is_scene = True
+        elif name == 'naglowek_akt':
+            is_act = True
+
+    for one_part in main_text:
+        name = one_part.tag
+        if is_act is False and is_scene is True:
+            if name == 'naglowek_czesc':
+                yield part_xml
+                last_node_part = True
+                main_xml_part[:] = [deepcopy(one_part)]
+            elif not last_node_part and name == "naglowek_scena":
+                yield part_xml
+                main_xml_part[:] = [deepcopy(one_part)]
+            else:
+                main_xml_part.append(deepcopy(one_part))
+                last_node_part = False
         else:
-            main_xml_part.append(deepcopy(one_part))
-            last_node_part = False
+            if name == 'naglowek_czesc':
+                yield part_xml
+                last_node_part = True
+                main_xml_part[:] = [deepcopy(one_part)]
+            elif not last_node_part and name in ("naglowek_rozdzial", "naglowek_akt", "srodtytul"):
+                yield part_xml
+                main_xml_part[:] = [deepcopy(one_part)]
+            else:
+                main_xml_part.append(deepcopy(one_part))
+                last_node_part = False
     yield part_xml
 
 
@@ -311,7 +390,7 @@ def transform_chunk(chunk_xml, chunk_no, annotations, empty=False, _empty_html_s
 
     toc = TOC()
     for element in chunk_xml[0]:
-        if element.tag in ("naglowek_czesc"):
+        if element.tag == "naglowek_czesc":
             toc.add(node_name(element), "part%d.html#book-text" % chunk_no)
         elif element.tag in ("naglowek_rozdzial", "naglowek_akt", "srodtytul"):
             toc.add(node_name(element), "part%d.html" % chunk_no)
@@ -328,18 +407,22 @@ def transform_chunk(chunk_xml, chunk_no, annotations, empty=False, _empty_html_s
         replace_by_verse(chunk_xml)
         html_tree = xslt(chunk_xml, get_resource('epub/xsltScheme.xsl'))
         chars = used_chars(html_tree.getroot())
-        output_html = etree.tostring(html_tree, method="html", pretty_print=True)
+        output_html = etree.tostring(
+            html_tree, pretty_print=True, xml_declaration=True,
+            encoding="utf-8",
+            doctype='<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" ' +
+                    '"http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">'
+        )
     return output_html, toc, chars
 
 
-def transform(wldoc, verbose=False,
-              style=None, html_toc=False,
-              sample=None, cover=None, flags=None):
+def transform(wldoc, verbose=False, style=None, html_toc=False,
+              sample=None, cover=None, flags=None, hyphenate=False, ilustr_path='', output_type='epub'):
     """ produces a EPUB file
 
     sample=n: generate sample e-book (with at least n paragraphs)
     cover: a cover.Cover factory or True for default
-    flags: less-advertising, without-fonts, working-copy, with-full-fonts
+    flags: less-advertising, without-fonts, working-copy
     """
 
     def transform_file(wldoc, chunk_counter=1, first=True, sample=None):
@@ -347,16 +430,24 @@ def transform(wldoc, verbose=False,
 
         replace_characters(wldoc.edoc.getroot())
 
+        hyphenator = set_hyph_language(wldoc.edoc.getroot()) if hyphenate else None
+        hyphenate_and_fix_conjunctions(wldoc.edoc.getroot(), hyphenator)
+
         # every input file will have a TOC entry,
         # pointing to starting chunk
         toc = TOC(wldoc.book_info.title, "part%d.html" % chunk_counter)
         chars = set()
         if first:
             # write book title page
-            html_tree = xslt(wldoc.edoc, get_resource('epub/xsltTitle.xsl'))
+            html_tree = xslt(wldoc.edoc, get_resource('epub/xsltTitle.xsl'), outputtype=output_type)
             chars = used_chars(html_tree.getroot())
-            zip.writestr('OPS/title.html',
-                 etree.tostring(html_tree, method="html", pretty_print=True))
+            html_string = etree.tostring(
+                html_tree, pretty_print=True, xml_declaration=True,
+                encoding="utf-8",
+                doctype='<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN"' +
+                        ' "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">'
+            )
+            zip.writestr('OPS/title.html', squeeze_whitespace(html_string))
             # add a title page TOC entry
             toc.add(u"Strona tytułowa", "title.html")
         elif wldoc.book_info.parts:
@@ -367,8 +458,13 @@ def transform(wldoc, verbose=False,
             else:
                 html_tree = xslt(wldoc.edoc, get_resource('epub/xsltChunkTitle.xsl'))
                 chars = used_chars(html_tree.getroot())
-                html_string = etree.tostring(html_tree, method="html", pretty_print=True)
-            zip.writestr('OPS/part%d.html' % chunk_counter, html_string)
+                html_string = etree.tostring(
+                    html_tree, pretty_print=True, xml_declaration=True,
+                    encoding="utf-8",
+                    doctype='<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN"' +
+                            ' "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">'
+                )
+            zip.writestr('OPS/part%d.html' % chunk_counter, squeeze_whitespace(html_string))
             add_to_manifest(manifest, chunk_counter)
             add_to_spine(spine, chunk_counter)
             chunk_counter += 1
@@ -394,7 +490,7 @@ def transform(wldoc, verbose=False,
 
                 toc.extend(chunk_toc)
                 chars = chars.union(chunk_chars)
-                zip.writestr('OPS/part%d.html' % chunk_counter, chunk_html)
+                zip.writestr('OPS/part%d.html' % chunk_counter, squeeze_whitespace(chunk_html))
                 add_to_manifest(manifest, chunk_counter)
                 add_to_spine(spine, chunk_counter)
                 chunk_counter += 1
@@ -407,7 +503,6 @@ def transform(wldoc, verbose=False,
 
         return toc, chunk_counter, chars, sample
 
-
     document = deepcopy(wldoc)
     del wldoc
 
@@ -415,9 +510,14 @@ def transform(wldoc, verbose=False,
         for flag in flags:
             document.edoc.getroot().set(flag, 'yes')
 
+    document.clean_ed_note()
+    document.clean_ed_note('abstrakt')
+
     # add editors info
-    document.edoc.getroot().set('editors', u', '.join(sorted(
-        editor.readable() for editor in document.editors())))
+    editors = document.editors()
+    if editors:
+        document.edoc.getroot().set('editors', u', '.join(sorted(
+            editor.readable() for editor in editors)))
     if document.book_info.funders:
         document.edoc.getroot().set('funders', u', '.join(
             document.book_info.funders))
@@ -432,28 +532,47 @@ def transform(wldoc, verbose=False,
     output_file = NamedTemporaryFile(prefix='librarian', suffix='.epub', delete=False)
     zip = zipfile.ZipFile(output_file, 'w', zipfile.ZIP_DEFLATED)
 
+    functions.reg_mathml_epub(zip)
+
+    if os.path.isdir(ilustr_path):
+        ilustr_elements = set(ilustr.get('src') for ilustr in document.edoc.findall('//ilustr'))
+        for i, filename in enumerate(os.listdir(ilustr_path)):
+            if filename not in ilustr_elements:
+                continue
+            file_path = os.path.join(ilustr_path, filename)
+            zip.write(file_path, os.path.join('OPS', filename))
+            image_id = 'image%s' % i
+            manifest.append(etree.fromstring(
+                '<item id="%s" href="%s" media-type="%s" />' % (image_id, filename, guess_type(file_path)[0])))
+
     # write static elements
     mime = zipfile.ZipInfo()
     mime.filename = 'mimetype'
     mime.compress_type = zipfile.ZIP_STORED
-    mime.extra = ''
-    zip.writestr(mime, 'application/epub+zip')
-    zip.writestr('META-INF/container.xml', '<?xml version="1.0" ?><container version="1.0" ' \
-                       'xmlns="urn:oasis:names:tc:opendocument:xmlns:container">' \
-                       '<rootfiles><rootfile full-path="OPS/content.opf" ' \
-                       'media-type="application/oebps-package+xml" />' \
-                       '</rootfiles></container>')
-    zip.write(get_resource('res/wl-logo-small.png'), os.path.join('OPS', 'logo_wolnelektury.png'))
-    zip.write(get_resource('res/jedenprocent.png'), os.path.join('OPS', 'jedenprocent.png'))
+    mime.extra = b''
+    zip.writestr(mime, b'application/epub+zip')
+    zip.writestr(
+        'META-INF/container.xml',
+        b'<?xml version="1.0" ?>'
+        b'<container version="1.0" '
+        b'xmlns="urn:oasis:names:tc:opendocument:xmlns:container">'
+        b'<rootfiles><rootfile full-path="OPS/content.opf" '
+        b'media-type="application/oebps-package+xml" />'
+        b'</rootfiles></container>'
+    )
+    zip.write(get_resource('res/wl-logo-small.png'),
+              os.path.join('OPS', 'logo_wolnelektury.png'))
+    zip.write(get_resource('res/jedenprocent.png'),
+              os.path.join('OPS', 'jedenprocent.png'))
     if not style:
         style = get_resource('epub/style.css')
     zip.write(style, os.path.join('OPS', 'style.css'))
 
     if cover:
         if cover is True:
-            cover = DefaultEbookCover
+            cover = make_cover
 
-        cover_file = StringIO()
+        cover_file = BytesIO()
         bound_cover = cover(document.book_info)
         bound_cover.save(cover_file)
         cover_name = 'cover.%s' % bound_cover.ext()
@@ -463,7 +582,11 @@ def transform(wldoc, verbose=False,
         cover_tree = etree.parse(get_resource('epub/cover.html'))
         cover_tree.find('//' + XHTMLNS('img')).set('src', cover_name)
         zip.writestr('OPS/cover.html', etree.tostring(
-                        cover_tree, method="html", pretty_print=True))
+            cover_tree, pretty_print=True, xml_declaration=True,
+            encoding="utf-8",
+            doctype='<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" ' +
+                    '"http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">'
+        ))
 
         if bound_cover.uses_dc_cover:
             if document.book_info.cover_by:
@@ -475,18 +598,20 @@ def transform(wldoc, verbose=False,
             '<item id="cover" href="cover.html" media-type="application/xhtml+xml" />'))
         manifest.append(etree.fromstring(
             '<item id="cover-image" href="%s" media-type="%s" />' % (cover_name, bound_cover.mime_type())))
-        spine.insert(0, etree.fromstring('<itemref idref="cover" linear="no" />'))
+        spine.insert(0, etree.fromstring('<itemref idref="cover"/>'))
         opf.getroot()[0].append(etree.fromstring('<meta name="cover" content="cover-image"/>'))
         guide.append(etree.fromstring('<reference href="cover.html" type="cover" title="Okładka"/>'))
 
-
     annotations = etree.Element('annotations')
 
-    toc_file = etree.fromstring('<?xml version="1.0" encoding="utf-8"?><!DOCTYPE ncx PUBLIC ' \
-                               '"-//NISO//DTD ncx 2005-1//EN" "http://www.daisy.org/z3986/2005/ncx-2005-1.dtd">' \
-                               '<ncx xmlns="http://www.daisy.org/z3986/2005/ncx/" xml:lang="pl" ' \
-                               'version="2005-1"><head></head><docTitle></docTitle><navMap>' \
-                               '</navMap></ncx>')
+    toc_file = etree.fromstring(
+        b'<?xml version="1.0" encoding="utf-8"?><!DOCTYPE ncx PUBLIC '
+        b'"-//NISO//DTD ncx 2005-1//EN" '
+        b'"http://www.daisy.org/z3986/2005/ncx-2005-1.dtd">'
+        b'<ncx xmlns="http://www.daisy.org/z3986/2005/ncx/" xml:lang="pl" '
+        b'version="2005-1"><head></head><docTitle></docTitle><navMap>'
+        b'</navMap></ncx>'
+    )
     nav_map = toc_file[-1]
 
     if html_toc:
@@ -512,28 +637,36 @@ def transform(wldoc, verbose=False,
         html_tree = xslt(annotations, get_resource('epub/xsltAnnotations.xsl'))
         chars = chars.union(used_chars(html_tree.getroot()))
         zip.writestr('OPS/annotations.html', etree.tostring(
-                            html_tree, method="html", pretty_print=True))
+            html_tree, pretty_print=True, xml_declaration=True,
+            encoding="utf-8",
+            doctype='<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" ' +
+                    '"http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">'
+        ))
 
     toc.add("Wesprzyj Wolne Lektury", "support.html")
     manifest.append(etree.fromstring(
         '<item id="support" href="support.html" media-type="application/xhtml+xml" />'))
     spine.append(etree.fromstring(
         '<itemref idref="support" />'))
-    html_string = open(get_resource('epub/support.html')).read()
+    html_string = open(get_resource('epub/support.html'), 'rb').read()
     chars.update(used_chars(etree.fromstring(html_string)))
-    zip.writestr('OPS/support.html', html_string)
+    zip.writestr('OPS/support.html', squeeze_whitespace(html_string))
 
     toc.add("Strona redakcyjna", "last.html")
     manifest.append(etree.fromstring(
         '<item id="last" href="last.html" media-type="application/xhtml+xml" />'))
     spine.append(etree.fromstring(
         '<itemref idref="last" />'))
-    html_tree = xslt(document.edoc, get_resource('epub/xsltLast.xsl'))
+    html_tree = xslt(document.edoc, get_resource('epub/xsltLast.xsl'), outputtype=output_type)
     chars.update(used_chars(html_tree.getroot()))
-    zip.writestr('OPS/last.html', etree.tostring(
-                        html_tree, method="html", pretty_print=True))
-
-    if not flags or not 'without-fonts' in flags:
+    zip.writestr('OPS/last.html', squeeze_whitespace(etree.tostring(
+        html_tree, pretty_print=True, xml_declaration=True,
+        encoding="utf-8",
+        doctype='<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" ' +
+                '"http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">'
+    )))
+
+    if not flags or 'without-fonts' not in flags:
         # strip fonts
         tmpdir = mkdtemp('-librarian-epub')
         try:
@@ -543,23 +676,25 @@ def transform(wldoc, verbose=False,
 
         os.chdir(os.path.join(os.path.dirname(os.path.realpath(__file__)), 'font-optimizer'))
         for fname in 'DejaVuSerif.ttf', 'DejaVuSerif-Bold.ttf', 'DejaVuSerif-Italic.ttf', 'DejaVuSerif-BoldItalic.ttf':
-            if not flags or not 'with-full-fonts' in flags:
-                optimizer_call = ['perl', 'subset.pl', '--chars', ''.join(chars).encode('utf-8'),
-                              get_resource('fonts/' + fname), os.path.join(tmpdir, fname)]              
-                if verbose:
-                    print "Running font-optimizer"
-                    subprocess.check_call(optimizer_call)
-                else:
-                    subprocess.check_call(optimizer_call, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
-                    zip.write(os.path.join(tmpdir, fname), os.path.join('OPS', fname))
+            optimizer_call = ['perl', 'subset.pl', '--chars',
+                              ''.join(chars).encode('utf-8'),
+                              get_resource('fonts/' + fname),
+                              os.path.join(tmpdir, fname)]
+            env = {"PERL_USE_UNSAFE_INC": "1"}
+            if verbose:
+                print("Running font-optimizer")
+                subprocess.check_call(optimizer_call, env=env)
             else:
-                zip.write(get_resource('fonts/' + fname), os.path.join('OPS', fname))
+                dev_null = open(os.devnull, 'w')
+                subprocess.check_call(optimizer_call, stdout=dev_null, stderr=dev_null, env=env)
+            zip.write(os.path.join(tmpdir, fname), os.path.join('OPS', fname))
             manifest.append(etree.fromstring(
                 '<item id="%s" href="%s" media-type="application/x-font-truetype" />' % (fname, fname)))
         rmtree(tmpdir)
         if cwd is not None:
             os.chdir(cwd)
-    zip.writestr('OPS/content.opf', etree.tostring(opf, pretty_print=True, xml_declaration = True, encoding='UTF-8'))
+    zip.writestr('OPS/content.opf', etree.tostring(opf, pretty_print=True,
+                 xml_declaration=True, encoding="utf-8"))
     title = document.book_info.title
     attributes = "dtb:uid", "dtb:depth", "dtb:totalPageCount", "dtb:maxPageNumber"
     for st in attributes:
@@ -576,7 +711,8 @@ def transform(wldoc, verbose=False,
         toc.add(u"Spis treści", "toc.html", index=1)
         zip.writestr('OPS/toc.html', toc.html().encode('utf-8'))
     toc.write_to_xml(nav_map)
-    zip.writestr('OPS/toc.ncx', etree.tostring(toc_file, pretty_print=True, xml_declaration = True, encoding='UTF-8'))
+    zip.writestr('OPS/toc.ncx', etree.tostring(toc_file, pretty_print=True,
+                 xml_declaration=True, encoding="utf-8"))
     zip.close()
 
     return OutputFile.from_filename(output_file.name)