#!/usr/bin/env python3
"""
Copyright 2019 Raúl Benencia
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
"""
import argparse
import os
import sys
import re
class DirCombiner():
ignore_files = ['.known', '.gitignore']
ignore_dirs = ['.git', '.svn', '_darcs']
def __init__(self, include, exclude, status_filename, verbose):
self.include = re.compile(include)
self.exclude = re.compile(exclude)
self.status_filename = status_filename
self.verbose = verbose
def _filter_files(self, filenames):
return [
fn for fn in filenames
if fn not in DirCombiner.ignore_files
and self.include.match(fn)
and not self.exclude.match(fn)
]
def _filter_dirs(self, directories):
return [
sd for sd in directories
if sd not in DirCombiner.ignore_dirs
and self.include.match(sd)
and not self.exclude.match(sd)
]
def _create_symlinks(self, status, dest, dirpath, filenames):
# Create symlinks for each file
for f in filenames:
src = os.path.abspath(os.path.normpath(os.path.join(dirpath, f)))
dst = os.path.normpath(os.path.join(dest, dirpath, f))
status.mark_as_seen(dst)
replace_msg = ""
if os.path.lexists(dst):
if not os.path.islink(dst):
sys.stderr.write(
"{} in {} is also in {}\n".format(f, dirpath, dest)
)
continue
elif os.path.realpath(dst) != src:
replace_msg = "(previously pointing to: {})".format(
os.path.realpath(dst))
try:
os.remove(dst)
except IOError:
raise DeleteFileError(dst)
else:
# Symlink is already pointing to the current file
continue
try:
os.symlink(src, dst)
except OSError:
raise CreateSymlinkError(dst)
if replace_msg == "" or (replace_msg != "" and self.verbose):
sys.stdout.write("{} -> {} {}\n".format(src, dst, replace_msg))
def _create_directories(self, dest, dirpath, subdirs):
for sd in subdirs:
dst = os.path.normpath(os.path.join(dest, dirpath, sd))
if os.path.lexists(dst):
if os.path.isdir(dst):
continue
else:
raise DirIsFileError(dst)
try:
os.mkdir(dst)
except OSError:
raise CreateDirError(dst)
sys.stdout.write(f"{dst} created\n")
def combine(self, dest, directories):
# Loop through all the directories. The later ones can override
# links from the previous ones.
for directory in directories:
try:
os.chdir(directory)
except OSError:
raise ChangeDirError(directory)
status = DirCombinerStatus(self.status_filename)
for dirpath, subdirs, filenames in os.walk('.'):
# Modify filenames and subdirs in place to reduce the
# scope of the search.
subdirs[:] = self._filter_dirs(subdirs)
filenames[:] = self._filter_files(filenames)
self._create_symlinks(status, dest, dirpath, filenames)
self._create_directories(dest, dirpath, subdirs)
status.finish()
class DirCombinerStatus():
def __init__(self, status_filename):
self._seen = []
self._status_filename = status_filename
try:
if os.path.exists(self._status_filename):
if not os.path.isfile(self._status_filename):
raise StatusIsNotFileError(self._status_filename)
else:
with open(self._status_filename, 'r') as f:
self._known = f.read().split('\n')[:-1]
else:
self._known = []
except IOError:
raise StatusFileError(self._status_filename)
def _clean_old(self):
old = {f for f in self._known if f not in self._seen}
for f in old:
try:
if os.path.lexists(f):
rp = os.path.realpath(f)
if not os.path.islink(f) or os.path.exists(rp):
sys.stderr.write(
f"Not deleting {f} as it's a valid file\n")
else:
os.remove(f)
sys.stdout.write(f"Deleted old file {f}\n")
except IOError:
raise DeleteFileError(f)
def mark_as_seen(self, filename):
self._seen.append(filename)
def finish(self):
self._clean_old()
with open(self._status_filename, 'w') as f:
for filename in self._seen:
f.write(filename + '\n')
class Error(Exception):
"""Base class for exceptions in this program """
msg = ''
def __init__(self, param):
self.param = param
def message(self):
return self.msg.format(self.param) + '\n'
class DirIsFileError(Error):
msg = 'Target directory {} already exists as a non-dir file.'
class CreateDirError(Error):
msg = 'Failure creating directory {}. Do you have appropriate permissions?'
class CreateSymlinkError(Error):
msg = 'Failure creating symlink {}. Do you have appropriate permissions?'
class ChangeDirError(Error):
msg = 'Failure changing to dir {}. Do you have appropriate permissions?'
class StatusFileError(Error):
msg = 'Error while opening status file {}. ' + \
'Do you have appropriate permissions?'
class StatusIsNotFile(Error):
msg = 'The status path {} does not have a file. Maybe it holds an old dir?'
class DeleteFileError(Error):
msg = 'Unable to delete file {}. Do you have appropriate permissions?'
def main():
parser = argparse.ArgumentParser()
parser.add_argument('-i', '--include', default='.*',
help='regex for filenames to include')
parser.add_argument('-e', '--exclude', default='^$',
help='regex for filenames to exclude')
parser.add_argument('-s', '--status-filename', default='.known',
help='regex for filenames to exclude')
parser.add_argument('dest', metavar='dest', type=str,
help='directory where to install links and filenames')
parser.add_argument('dirs', metavar='dir', type=str, nargs='+',
help='directories to retrieve filenames from')
parser.add_argument('-v', '--verbose', default=False,
help='Verbose output')
args = parser.parse_args()
dc = DirCombiner(args.include, args.exclude, args.status_filename, args.verbose)
try:
dc.combine(args.dest, args.dirs)
except Error as e:
sys.stderr.write(e.message())
sys.exit(1)
if __name__ == "__main__":
main()