#!/usr/bin/env python3

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# the software to the public domain. We make this dedication for the

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# and successors. We intend this dedication to be an overt act of

# relinquishment in perpetuity of all present and future rights to

# this software under copyright law.

# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,

# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF

# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND

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"""Check for broken links.

This finds links like this...

[click here](some-file.md)

[or here](../some/path/another-file.md)


...but not like this:

[some website](http://github.com/)

[another website](https://github.com/)

[local link](#some-title)

"""

import os

import posixpath

import common

def check(this_file, target, title, titledict):

"""Check if a link's target is like it should be.

Return an error message string or "ok".

"""

if target.startswith(('http://', 'https://')):

# We don't need this currently, but checking these links could

# be added later.

return "ok"

path = posixpath.join(posixpath.dirname(this_file), target)

path = posixpath.normpath(path)

real_path = common.slashfix(path)

if not os.path.exists(real_path):

return "doesn't exist"

if target.endswith('/'):

# A directory.

if not os.path.isdir(real_path):

return "not a directory"

else:

# A file.

if not os.path.isfile(real_path):

return "not a file"

if title is not None and title not in titledict[path]:

return "no title named %s" % title

return "ok"

def find_titles(filename):

"""Read titles of a markdown file and return a list of them."""

result = []

with common.slashfix_open(filename, 'r') as f:

for line in f:

if line.startswith('```'):

# it's a code block, let's skip to the end of it to

# avoid detecting comments as titles

while f.readline().rstrip() != '```':

pass

if line.startswith('#'):

# found a title

result.append(common.header_link(line.lstrip('#').strip()))

return result

def find_links(this_file):

"""Read links of a markdown file.

Return a list of (target, title, lineno) pairs where title can be None.

"""

result = []

with common.slashfix_open(this_file, 'r') as f:

for match, lineno in common.find_links(f):

target = match.group(2)

if '#' in target:

file, title = target.split('#', 1)

if not file:

# link to this file, [blabla](#hi)

file = posixpath.basename(this_file)

else:

file = target

title = None

result.append((file, title, lineno))

return result

def get_line(filename, lineno):

"""Return the lineno'th line of a file."""

with common.slashfix_open(filename, 'r') as f:

for lineno2, line in enumerate(f, start=1):

if lineno == lineno2:

return line

raise ValueError("%s is less than %d lines long" % (filename, lineno))

def main():

print("Searching for titles and links...")

titledict = {} # {filename: [title1, title2, ...]}

linkdict = {} # {filename: [(file, title, lineno), ...])

for path in common.get_markdown_files():

titledict[path] = find_titles(path)

linkdict[path] = find_links(path)

print("Checking the links...")

total = 0

broken = 0

for filename, linklist in linkdict.items():

for target, title, lineno in linklist:

status = check(filename, target, title, titledict)

if status != "ok":

print(" file %s, line %d: %s" % (filename, lineno, status))

print(" %s" % get_line(filename, lineno))

broken += 1

total += 1

print("%d/%d links seem to be broken." % (broken, total))

if __name__ == '__main__':

main()