#!/usr/bin/env python3
# This script transforms markdown files into html and (optionally) nroff. The
# output files are written into the current directory named for the input file
# without the .md suffix and either the .html suffix or no suffix.
#
# If the input .md file has a section number at the end of the name (e.g.,
# rsync.1.md) a nroff file is also output (PROJ.NUM.md -> PROJ.NUM).
#
# The markdown input format has one extra extension: if a numbered list starts
# at 0, it is turned into a description list. The dl's dt tag is taken from the
# contents of the first tag inside the li, which is usually a p, code, or
# strong tag.
#
# The cmarkgfm or commonmark lib is used to transforms the input file into
# html. Then, the html.parser is used as a state machine that lets us tweak
# the html and (optionally) output nroff data based on the html tags.
#
# If the string @USE_GFM_PARSER@ exists in the file, the string is removed and
# a github-flavored-markup parser is used to parse the file.
#
# The man-page .md files also get the vars @VERSION@, @BINDIR@, and @LIBDIR@
# substituted. Some of these values depend on the Makefile $(prefix) (see the
# generated Makefile). If the maintainer wants to build files for /usr/local
# while creating release-ready man-page files for /usr, use the environment to
# set RSYNC_OVERRIDE_PREFIX=/usr.
# Copyright (C) 2020 - 2021 Wayne Davison
#
# This program is freely redistributable.
import os, sys, re, argparse, subprocess, time
from html.parser import HTMLParser
VALID_PAGES = 'README INSTALL COPYING rsync.1 rrsync.1 rsync-ssl.1 rsyncd.conf.5'.split()
CONSUMES_TXT = set('h1 h2 h3 p li pre'.split())
HTML_START = """\
%TITLE%
"""
TABLE_STYLE = """\
table {
border-color: grey;
border-spacing: 0;
}
tr {
border-top: 1px solid grey;
}
tr:nth-child(2n) {
background-color: #f6f8fa;
}
th, td {
border: 1px solid #dfe2e5;
text-align: center;
padding-left: 1em;
padding-right: 1em;
}
"""
MAN_HTML_END = """\
%s
"""
HTML_END = """\
"""
MAN_START = r"""
.TH "%s" "%s" "%s" "%s" "User Commands"
.\" prefix=%s
""".lstrip()
MAN_END = """\
"""
NORM_FONT = ('\1', r"\fP")
BOLD_FONT = ('\2', r"\fB")
UNDR_FONT = ('\3', r"\fI")
NBR_DASH = ('\4', r"\-")
NBR_SPACE = ('\xa0', r"\ ")
FILENAME_RE = re.compile(r'^(?P(?P.+/)?(?P(?P[^/]+?)(\.(?P\d+))?)\.md)$')
ASSIGNMENT_RE = re.compile(r'^(\w+)=(.+)')
VER_RE = re.compile(r'^#define\s+RSYNC_VERSION\s+"(\d.+?)"', re.M)
TZ_RE = re.compile(r'^#define\s+MAINTAINER_TZ_OFFSET\s+(-?\d+(\.\d+)?)', re.M)
VAR_REF_RE = re.compile(r'\$\{(\w+)\}')
VERSION_RE = re.compile(r' (\d[.\d]+)[, ]')
BIN_CHARS_RE = re.compile(r'[\1-\7]+')
SPACE_DOUBLE_DASH_RE = re.compile(r'\s--(\s)')
NON_SPACE_SINGLE_DASH_RE = re.compile(r'(^|\W)-')
WHITESPACE_RE = re.compile(r'\s')
CODE_BLOCK_RE = re.compile(r'[%s]([^=%s]+)[=%s]' % (BOLD_FONT[0], NORM_FONT[0], NORM_FONT[0]))
NBR_DASH_RE = re.compile(r'[%s]' % NBR_DASH[0])
INVALID_TARGET_CHARS_RE = re.compile(r'[^-A-Za-z0-9._]')
INVALID_START_CHAR_RE = re.compile(r'^([^A-Za-z0-9])')
MANIFY_LINESTART_RE = re.compile(r"^(['.])", flags=re.M)
md_parser = None
env_subs = { }
warning_count = 0
def main():
for mdfn in args.mdfiles:
parse_md_file(mdfn)
if args.test:
print("The test was successful.")
def parse_md_file(mdfn):
fi = FILENAME_RE.match(mdfn)
if not fi:
die('Failed to parse a md input file name:', mdfn)
fi = argparse.Namespace(**fi.groupdict())
fi.want_manpage = not not fi.sect
if fi.want_manpage:
fi.title = fi.prog + '(' + fi.sect + ') manpage'
else:
fi.title = fi.prog + ' for rsync'
if fi.want_manpage:
if not env_subs:
find_man_substitutions()
prog_ver = 'rsync ' + env_subs['VERSION']
if fi.prog != 'rsync':
prog_ver = fi.prog + ' from ' + prog_ver
fi.man_headings = (fi.prog, fi.sect, env_subs['date'], prog_ver, env_subs['prefix'])
with open(mdfn, 'r', encoding='utf-8') as fh:
txt = fh.read()
use_gfm_parser = '@USE_GFM_PARSER@' in txt
if use_gfm_parser:
txt = txt.replace('@USE_GFM_PARSER@', '')
if fi.want_manpage:
txt = (txt.replace('@VERSION@', env_subs['VERSION'])
.replace('@BINDIR@', env_subs['bindir'])
.replace('@LIBDIR@', env_subs['libdir']))
if use_gfm_parser:
if not gfm_parser:
die('Input file requires cmarkgfm parser:', mdfn)
fi.html_in = gfm_parser(txt)
else:
fi.html_in = md_parser(txt)
txt = None
TransformHtml(fi)
if args.test:
return
output_list = [ (fi.name + '.html', fi.html_out) ]
if fi.want_manpage:
output_list += [ (fi.name, fi.man_out) ]
for fn, txt in output_list:
if args.dest and args.dest != '.':
fn = os.path.join(args.dest, fn)
if os.path.lexists(fn):
os.unlink(fn)
print("Wrote:", fn)
with open(fn, 'w', encoding='utf-8') as fh:
fh.write(txt)
def find_man_substitutions():
srcdir = os.path.dirname(sys.argv[0]) + '/'
mtime = 0
git_dir = srcdir + '.git'
if os.path.lexists(git_dir):
mtime = int(subprocess.check_output(['git', '--git-dir', git_dir, 'log', '-1', '--format=%at']))
# Allow "prefix" to be overridden via the environment:
env_subs['prefix'] = os.environ.get('RSYNC_OVERRIDE_PREFIX', None)
if args.test:
env_subs['VERSION'] = '1.0.0'
env_subs['bindir'] = '/usr/bin'
env_subs['libdir'] = '/usr/lib/rsync'
tz_offset = 0
else:
for fn in (srcdir + 'version.h', 'Makefile'):
try:
st = os.lstat(fn)
except OSError:
die('Failed to find', srcdir + fn)
if not mtime:
mtime = st.st_mtime
with open(srcdir + 'version.h', 'r', encoding='utf-8') as fh:
txt = fh.read()
m = VER_RE.search(txt)
env_subs['VERSION'] = m.group(1)
m = TZ_RE.search(txt) # the tzdata lib may not be installed, so we use a simple hour offset
tz_offset = float(m.group(1)) * 60 * 60
with open('Makefile', 'r', encoding='utf-8') as fh:
for line in fh:
m = ASSIGNMENT_RE.match(line)
if not m:
continue
var, val = (m.group(1), m.group(2))
if var == 'prefix' and env_subs[var] is not None:
continue
while VAR_REF_RE.search(val):
val = VAR_REF_RE.sub(lambda m: env_subs[m.group(1)], val)
env_subs[var] = val
if var == 'srcdir':
break
env_subs['date'] = time.strftime('%d %b %Y', time.gmtime(mtime + tz_offset)).lstrip('0')
def html_via_commonmark(txt):
return commonmark.HtmlRenderer().render(commonmark.Parser().parse(txt))
class TransformHtml(HTMLParser):
def __init__(self, fi):
HTMLParser.__init__(self, convert_charrefs=True)
self.fn = fi.fn
st = self.state = argparse.Namespace(
list_state = [ ],
p_macro = ".P\n",
at_first_tag_in_li = False,
at_first_tag_in_dd = False,
dt_from = None,
in_pre = False,
in_code = False,
html_out = [ HTML_START.replace('%TITLE%', fi.title) ],
man_out = [ ],
txt = '',
want_manpage = fi.want_manpage,
created_hashtags = set(),
derived_hashtags = set(),
referenced_hashtags = set(),
bad_hashtags = set(),
latest_targets = [ ],
opt_prefix = 'opt',
a_href = None,
a_href_external = False,
a_txt_start = None,
after_a_tag = False,
target_suf = '',
)
if st.want_manpage:
st.man_out.append(MAN_START % fi.man_headings)
if '' in fi.html_in:
st.html_out[0] = st.html_out[0].replace('', TABLE_STYLE + '')
self.feed(fi.html_in)
fi.html_in = None
if st.want_manpage:
st.html_out.append(MAN_HTML_END % env_subs['date'])
st.html_out.append(HTML_END)
st.man_out.append(MAN_END)
fi.html_out = ''.join(st.html_out)
st.html_out = None
fi.man_out = ''.join(st.man_out)
st.man_out = None
for tgt, txt in st.derived_hashtags:
derived = txt2target(txt, tgt)
if derived not in st.created_hashtags:
txt = BIN_CHARS_RE.sub('', txt.replace(NBR_DASH[0], '-').replace(NBR_SPACE[0], ' '))
warn('Unknown derived hashtag link in', self.fn, 'based on:', (tgt, txt))
for bad in st.bad_hashtags:
if bad in st.created_hashtags:
warn('Missing "#" in hashtag link in', self.fn + ':', bad)
else:
warn('Unknown non-hashtag link in', self.fn + ':', bad)
for bad in st.referenced_hashtags - st.created_hashtags:
warn('Unknown hashtag link in', self.fn + ':', '#' + bad)
def handle_UE(self):
st = self.state
if st.txt.startswith(('.', ',', '!', '?', ';', ':')):
st.man_out[-1] = ".UE " + st.txt[0] + "\n"
st.txt = st.txt[1:]
st.after_a_tag = False
def handle_starttag(self, tag, attrs_list):
st = self.state
if args.debug:
self.output_debug('START', (tag, attrs_list))
if st.at_first_tag_in_li:
if st.list_state[-1] == 'dl':
st.dt_from = tag
if tag == 'p':
tag = 'dt'
else:
st.html_out.append('
')
elif tag == 'p':
st.at_first_tag_in_dd = True # Kluge to suppress a .P at the start of an li.
st.at_first_tag_in_li = False
if tag == 'p':
if not st.at_first_tag_in_dd:
st.man_out.append(st.p_macro)
elif tag == 'li':
st.at_first_tag_in_li = True
lstate = st.list_state[-1]
if lstate == 'dl':
return
if lstate == 'o':
st.man_out.append(".IP o\n")
else:
st.man_out.append(".IP " + str(lstate) + ".\n")
st.list_state[-1] += 1
elif tag == 'blockquote':
st.man_out.append(".RS 4\n")
elif tag == 'pre':
st.in_pre = True
st.man_out.append(st.p_macro + ".nf\n")
elif tag == 'code' and not st.in_pre:
st.in_code = True
st.txt += BOLD_FONT[0]
elif tag == 'strong' or tag == 'b':
st.txt += BOLD_FONT[0]
elif tag == 'em' or tag == 'i':
if st.want_manpage:
tag = 'u' # Change it into underline to be more like the manpage
st.txt += UNDR_FONT[0]
elif tag == 'ol':
start = 1
for var, val in attrs_list:
if var == 'start':
start = int(val) # We only support integers.
break
if st.list_state:
st.man_out.append(".RS\n")
if start == 0:
tag = 'dl'
attrs_list = [ ]
st.list_state.append('dl')
else:
st.list_state.append(start)
st.man_out.append(st.p_macro)
st.p_macro = ".IP\n"
elif tag == 'ul':
st.man_out.append(st.p_macro)
if st.list_state:
st.man_out.append(".RS\n")
st.p_macro = ".IP\n"
st.list_state.append('o')
elif tag == 'hr':
st.man_out.append(".l\n")
st.html_out.append("")
return
elif tag == 'a':
st.a_href = None
for var, val in attrs_list:
if var == 'href':
if val.startswith(('https://', 'http://', 'mailto:', 'ftp:')):
if st.after_a_tag:
self.handle_UE()
st.man_out.append(manify(st.txt.strip()) + "\n")
st.man_out.append(".UR " + val + "\n")
st.txt = ''
st.a_href = val
st.a_href_external = True
elif '#' in val:
pg, tgt = val.split('#', 1)
if pg and pg not in VALID_PAGES or '#' in tgt:
st.bad_hashtags.add(val)
elif tgt in ('', 'opt', 'dopt'):
st.a_href = val
st.a_href_external = False
elif pg == '':
st.referenced_hashtags.add(tgt)
if tgt in st.latest_targets:
warn('Found link to the current section in', self.fn + ':', val)
elif val not in VALID_PAGES:
st.bad_hashtags.add(val)
st.a_txt_start = len(st.txt)
st.html_out.append('<' + tag + ''.join(' ' + var + '="' + htmlify(val) + '"' for var, val in attrs_list) + '>')
st.at_first_tag_in_dd = False
def handle_endtag(self, tag):
st = self.state
if args.debug:
self.output_debug('END', (tag,))
if st.after_a_tag:
self.handle_UE()
if tag in CONSUMES_TXT or st.dt_from == tag:
txt = st.txt.strip()
st.txt = ''
else:
txt = None
add_to_txt = None
if tag == 'h1':
tgt = txt
target_suf = ''
if tgt.startswith('NEWS for '):
m = VERSION_RE.search(tgt)
if m:
tgt = m.group(1)
st.target_suf = '-' + tgt
self.add_targets(tag, tgt)
elif tag == 'h2':
st.man_out.append(st.p_macro + '.SH "' + manify(txt) + '"\n')
self.add_targets(tag, txt, st.target_suf)
st.opt_prefix = 'dopt' if txt == 'DAEMON OPTIONS' else 'opt'
elif tag == 'h3':
st.man_out.append(st.p_macro + '.SS "' + manify(txt) + '"\n')
self.add_targets(tag, txt, st.target_suf)
elif tag == 'p':
if st.dt_from == 'p':
tag = 'dt'
st.man_out.append('.IP "' + manify(txt) + '"\n')
if txt.startswith(BOLD_FONT[0]):
self.add_targets(tag, txt)
st.dt_from = None
elif txt != '':
st.man_out.append(manify(txt) + "\n")
elif tag == 'li':
if st.list_state[-1] == 'dl':
if st.at_first_tag_in_li:
die("Invalid 0. -> td translation")
tag = 'dd'
if txt != '':
st.man_out.append(manify(txt) + "\n")
st.at_first_tag_in_li = False
elif tag == 'blockquote':
st.man_out.append(".RE\n")
elif tag == 'pre':
st.in_pre = False
st.man_out.append(manify(txt) + "\n.fi\n")
elif (tag == 'code' and not st.in_pre):
st.in_code = False
add_to_txt = NORM_FONT[0]
elif tag == 'strong' or tag == 'b':
add_to_txt = NORM_FONT[0]
elif tag == 'em' or tag == 'i':
if st.want_manpage:
tag = 'u' # Change it into underline to be more like the manpage
add_to_txt = NORM_FONT[0]
elif tag == 'ol' or tag == 'ul':
if st.list_state.pop() == 'dl':
tag = 'dl'
if st.list_state:
st.man_out.append(".RE\n")
else:
st.p_macro = ".P\n"
st.at_first_tag_in_dd = False
elif tag == 'hr':
return
elif tag == 'a':
if st.a_href_external:
st.txt = st.txt.strip()
if args.force_link_text or st.a_href != st.txt:
st.man_out.append(manify(st.txt) + "\n")
st.man_out.append(".UE\n") # This might get replaced with a punctuation version in handle_UE()
st.after_a_tag = True
st.a_href_external = False
st.txt = ''
elif st.a_href:
atxt = st.txt[st.a_txt_start:]
find = 'href="' + st.a_href + '"'
for j in range(len(st.html_out)-1, 0, -1):
if find in st.html_out[j]:
pg, tgt = st.a_href.split('#', 1)
derived = txt2target(atxt, tgt)
if pg == '':
if derived in st.latest_targets:
warn('Found link to the current section in', self.fn + ':', st.a_href)
st.derived_hashtags.add((tgt, atxt))
st.html_out[j] = st.html_out[j].replace(find, 'href="' + pg + '#' + derived + '"')
break
else:
die('INTERNAL ERROR: failed to find href in html data:', find)
st.html_out.append('')
if add_to_txt:
if txt is None:
st.txt += add_to_txt
else:
txt += add_to_txt
if st.dt_from == tag:
st.man_out.append('.IP "' + manify(txt) + '"\n')
st.html_out.append('
')
st.at_first_tag_in_dd = True
def handle_data(self, txt):
st = self.state
if '](' in txt:
warn('Malformed link in', self.fn + ':', txt)
if args.debug:
self.output_debug('DATA', (txt,))
if st.in_pre:
html = htmlify(txt)
else:
txt = SPACE_DOUBLE_DASH_RE.sub(NBR_SPACE[0] + r'--\1', txt).replace('--', NBR_DASH[0]*2)
txt = NON_SPACE_SINGLE_DASH_RE.sub(r'\1' + NBR_DASH[0], txt)
html = htmlify(txt)
if st.in_code:
txt = WHITESPACE_RE.sub(NBR_SPACE[0], txt)
html = html.replace(NBR_DASH[0], '-').replace(NBR_SPACE[0], ' ') # is non-breaking in CSS
st.html_out.append(html.replace(NBR_SPACE[0], ' ').replace(NBR_DASH[0], '-'))
st.txt += txt
def add_targets(self, tag, txt, suf=None):
st = self.state
tag = '<' + tag + '>'
targets = CODE_BLOCK_RE.findall(txt)
if not targets:
targets = [ txt ]
tag_pos = 0
for txt in targets:
txt = txt2target(txt, st.opt_prefix)
if not txt:
continue
if suf:
txt += suf
if txt in st.created_hashtags:
for j in range(2, 1000):
chk = txt + '-' + str(j)
if chk not in st.created_hashtags:
print('Made link target unique:', chk)
txt = chk
break
if tag_pos == 0:
tag_pos -= 1
while st.html_out[tag_pos] != tag:
tag_pos -= 1
st.html_out[tag_pos] = tag[:-1] + ' id="' + txt + '">'
st.html_out.append('')
tag_pos -= 1 # take into account the append
else:
st.html_out[tag_pos] = '' + st.html_out[tag_pos]
st.created_hashtags.add(txt)
st.latest_targets = targets
def output_debug(self, event, extra):
import pprint
st = self.state
if args.debug < 2:
st = argparse.Namespace(**vars(st))
if len(st.html_out) > 2:
st.html_out = ['...'] + st.html_out[-2:]
if len(st.man_out) > 2:
st.man_out = ['...'] + st.man_out[-2:]
print(event, extra)
pprint.PrettyPrinter(indent=2).pprint(vars(st))
def txt2target(txt, opt_prefix):
txt = txt.strip().rstrip(':')
m = CODE_BLOCK_RE.search(txt)
if m:
txt = m.group(1)
txt = NBR_DASH_RE.sub('-', txt)
txt = BIN_CHARS_RE.sub('', txt)
txt = INVALID_TARGET_CHARS_RE.sub('_', txt)
if opt_prefix and txt.startswith('-'):
txt = opt_prefix + txt
else:
txt = INVALID_START_CHAR_RE.sub(r't\1', txt)
return txt
def manify(txt):
return MANIFY_LINESTART_RE.sub(r'\&\1', txt.replace('\\', '\\\\')
.replace(NBR_SPACE[0], NBR_SPACE[1])
.replace(NBR_DASH[0], NBR_DASH[1])
.replace(NORM_FONT[0], NORM_FONT[1])
.replace(BOLD_FONT[0], BOLD_FONT[1])
.replace(UNDR_FONT[0], UNDR_FONT[1]))
def htmlify(txt):
return txt.replace('&', '&').replace('<', '<').replace('>', '>').replace('"', '"')
def warn(*msg):
print(*msg, file=sys.stderr)
global warning_count
warning_count += 1
def die(*msg):
warn(*msg)
sys.exit(1)
if __name__ == '__main__':
parser = argparse.ArgumentParser(description="Convert markdown into html and (optionally) nroff. Each input filename must have a .md suffix, which is changed to .html for the output filename. If the input filename ends with .num.md (e.g. foo.1.md) then a nroff file is also output with the input filename's .md suffix removed (e.g. foo.1).", add_help=False)
parser.add_argument('--test', action='store_true', help="Just test the parsing without outputting any files.")
parser.add_argument('--dest', metavar='DIR', help="Create files in DIR instead of the current directory.")
parser.add_argument('--force-link-text', action='store_true', help="Don't remove the link text if it matches the link href. Useful when nroff doesn't understand .UR and .UE.")
parser.add_argument('--debug', '-D', action='count', default=0, help='Output copious info on the html parsing. Repeat for even more.')
parser.add_argument("--help", "-h", action="help", help="Output this help message and exit.")
parser.add_argument("mdfiles", metavar='FILE.md', nargs='+', help="One or more .md files to convert.")
args = parser.parse_args()
try:
import cmarkgfm
md_parser = cmarkgfm.markdown_to_html
gfm_parser = cmarkgfm.github_flavored_markdown_to_html
except:
try:
import commonmark
md_parser = html_via_commonmark
except:
die("Failed to find cmarkgfm or commonmark for python3.")
gfm_parser = None
main()
if warning_count:
sys.exit(1)