Source code for llnl.util.filesystem

# Copyright 2013-2022 Lawrence Livermore National Security, LLC and other
# Spack Project Developers. See the top-level COPYRIGHT file for details.
#
# SPDX-License-Identifier: (Apache-2.0 OR MIT)
import collections
import errno
import glob
import hashlib
import itertools
import numbers
import os
import re
import shutil
import stat
import sys
import tempfile
from contextlib import contextmanager
from sys import platform as _platform

import six

from llnl.util import tty
from llnl.util.compat import Sequence
from llnl.util.lang import dedupe, memoized
from llnl.util.symlink import symlink

from spack.util.executable import Executable
from spack.util.path import path_to_os_path, system_path_filter

is_windows = _platform == 'win32'

if not is_windows:
    import grp
    import pwd
else:
    import win32security


__all__ = [
    'FileFilter',
    'FileList',
    'HeaderList',
    'LibraryList',
    'ancestor',
    'can_access',
    'change_sed_delimiter',
    'copy_mode',
    'filter_file',
    'find',
    'find_headers',
    'find_all_headers',
    'find_libraries',
    'find_system_libraries',
    'fix_darwin_install_name',
    'force_remove',
    'force_symlink',
    'getuid',
    'chgrp',
    'chmod_x',
    'copy',
    'install',
    'copy_tree',
    'install_tree',
    'is_exe',
    'join_path',
    'last_modification_time_recursive',
    'library_extensions',
    'mkdirp',
    'partition_path',
    'prefixes',
    'remove_dead_links',
    'remove_directory_contents',
    'remove_if_dead_link',
    'remove_linked_tree',
    'rename',
    'set_executable',
    'set_install_permissions',
    'touch',
    'touchp',
    'traverse_tree',
    'unset_executable_mode',
    'working_dir',
    'keep_modification_time'
]


[docs]def getuid(): if is_windows: import ctypes if ctypes.windll.shell32.IsUserAnAdmin() == 0: return 1 return 0 else: return os.getuid()
[docs]@system_path_filter def rename(src, dst): # On Windows, os.rename will fail if the destination file already exists if is_windows: if os.path.exists(dst): os.remove(dst) os.rename(src, dst)
@system_path_filter def path_contains_subdirectory(path, root): norm_root = os.path.abspath(root).rstrip(os.path.sep) + os.path.sep norm_path = os.path.abspath(path).rstrip(os.path.sep) + os.path.sep return norm_path.startswith(norm_root) #: This generates the library filenames that may appear on any OS. library_extensions = ['a', 'la', 'so', 'tbd', 'dylib'] def possible_library_filenames(library_names): """Given a collection of library names like 'libfoo', generate the set of library filenames that may be found on the system (e.g. libfoo.so). """ lib_extensions = library_extensions return set( '.'.join((lib, extension)) for lib, extension in itertools.product(library_names, lib_extensions)) def paths_containing_libs(paths, library_names): """Given a collection of filesystem paths, return the list of paths that which include one or more of the specified libraries. """ required_lib_fnames = possible_library_filenames(library_names) rpaths_to_include = [] paths = path_to_os_path(*paths) for path in paths: fnames = set(os.listdir(path)) if fnames & required_lib_fnames: rpaths_to_include.append(path) return rpaths_to_include @system_path_filter def same_path(path1, path2): norm1 = os.path.abspath(path1).rstrip(os.path.sep) norm2 = os.path.abspath(path2).rstrip(os.path.sep) return norm1 == norm2
[docs]def filter_file(regex, repl, *filenames, **kwargs): r"""Like sed, but uses python regular expressions. Filters every line of each file through regex and replaces the file with a filtered version. Preserves mode of filtered files. As with re.sub, ``repl`` can be either a string or a callable. If it is a callable, it is passed the match object and should return a suitable replacement string. If it is a string, it can contain ``\1``, ``\2``, etc. to represent back-substitution as sed would allow. Parameters: regex (str): The regular expression to search for repl (str): The string to replace matches with *filenames: One or more files to search and replace Keyword Arguments: string (bool): Treat regex as a plain string. Default it False backup (bool): Make backup file(s) suffixed with ``~``. Default is True ignore_absent (bool): Ignore any files that don't exist. Default is False stop_at (str): Marker used to stop scanning the file further. If a text line matches this marker filtering is stopped and the rest of the file is copied verbatim. Default is to filter until the end of the file. """ string = kwargs.get('string', False) backup = kwargs.get('backup', False) ignore_absent = kwargs.get('ignore_absent', False) stop_at = kwargs.get('stop_at', None) # Allow strings to use \1, \2, etc. for replacement, like sed if not callable(repl): unescaped = repl.replace(r'\\', '\\') def replace_groups_with_groupid(m): def groupid_to_group(x): return m.group(int(x.group(1))) return re.sub(r'\\([1-9])', groupid_to_group, unescaped) repl = replace_groups_with_groupid if string: regex = re.escape(regex) filenames = path_to_os_path(*filenames) for filename in filenames: msg = 'FILTER FILE: {0} [replacing "{1}"]' tty.debug(msg.format(filename, regex)) backup_filename = filename + "~" tmp_filename = filename + ".spack~" if ignore_absent and not os.path.exists(filename): msg = 'FILTER FILE: file "{0}" not found. Skipping to next file.' tty.debug(msg.format(filename)) continue # Create backup file. Don't overwrite an existing backup # file in case this file is being filtered multiple times. if not os.path.exists(backup_filename): shutil.copy(filename, backup_filename) # Create a temporary file to read from. We cannot use backup_filename # in case filter_file is invoked multiple times on the same file. shutil.copy(filename, tmp_filename) try: extra_kwargs = {} if sys.version_info > (3, 0): extra_kwargs = {'errors': 'surrogateescape'} # Open as a text file and filter until the end of the file is # reached or we found a marker in the line if it was specified with open(tmp_filename, mode='r', **extra_kwargs) as input_file: with open(filename, mode='w', **extra_kwargs) as output_file: # Using iter and readline is a workaround needed not to # disable input_file.tell(), which will happen if we call # input_file.next() implicitly via the for loop for line in iter(input_file.readline, ''): if stop_at is not None: current_position = input_file.tell() if stop_at == line.strip(): output_file.write(line) break filtered_line = re.sub(regex, repl, line) output_file.write(filtered_line) else: current_position = None # If we stopped filtering at some point, reopen the file in # binary mode and copy verbatim the remaining part if current_position and stop_at: with open(tmp_filename, mode='rb') as input_file: input_file.seek(current_position) with open(filename, mode='ab') as output_file: output_file.writelines(input_file.readlines()) except BaseException: # clean up the original file on failure. shutil.move(backup_filename, filename) raise finally: os.remove(tmp_filename) if not backup and os.path.exists(backup_filename): os.remove(backup_filename)
[docs]class FileFilter(object): """Convenience class for calling ``filter_file`` a lot.""" def __init__(self, *filenames): self.filenames = filenames
[docs] def filter(self, regex, repl, **kwargs): return filter_file(regex, repl, *self.filenames, **kwargs)
[docs]def change_sed_delimiter(old_delim, new_delim, *filenames): """Find all sed search/replace commands and change the delimiter. e.g., if the file contains seds that look like ``'s///'``, you can call ``change_sed_delimiter('/', '@', file)`` to change the delimiter to ``'@'``. Note that this routine will fail if the delimiter is ``'`` or ``"``. Handling those is left for future work. Parameters: old_delim (str): The delimiter to search for new_delim (str): The delimiter to replace with *filenames: One or more files to search and replace """ assert(len(old_delim) == 1) assert(len(new_delim) == 1) # TODO: handle these cases one day? assert(old_delim != '"') assert(old_delim != "'") assert(new_delim != '"') assert(new_delim != "'") whole_lines = "^s@([^@]*)@(.*)@[gIp]$" whole_lines = whole_lines.replace('@', old_delim) single_quoted = r"'s@((?:\\'|[^@'])*)@((?:\\'|[^'])*)@[gIp]?'" single_quoted = single_quoted.replace('@', old_delim) double_quoted = r'"s@((?:\\"|[^@"])*)@((?:\\"|[^"])*)@[gIp]?"' double_quoted = double_quoted.replace('@', old_delim) repl = r's@\1@\2@g' repl = repl.replace('@', new_delim) filenames = path_to_os_path(*filenames) for f in filenames: filter_file(whole_lines, repl, f) filter_file(single_quoted, "'%s'" % repl, f) filter_file(double_quoted, '"%s"' % repl, f)
@system_path_filter(arg_slice=slice(1)) def get_owner_uid(path, err_msg=None): if not os.path.exists(path): mkdirp(path, mode=stat.S_IRWXU) p_stat = os.stat(path) if p_stat.st_mode & stat.S_IRWXU != stat.S_IRWXU: tty.error("Expected {0} to support mode {1}, but it is {2}" .format(path, stat.S_IRWXU, p_stat.st_mode)) raise OSError(errno.EACCES, err_msg.format(path, path) if err_msg else "") else: p_stat = os.stat(path) if _platform != "win32": owner_uid = p_stat.st_uid else: sid = win32security.GetFileSecurity( path, win32security.OWNER_SECURITY_INFORMATION) \ .GetSecurityDescriptorOwner() owner_uid = win32security.LookupAccountSid(None, sid)[0] return owner_uid
[docs]@system_path_filter def set_install_permissions(path): """Set appropriate permissions on the installed file.""" # If this points to a file maintained in a Spack prefix, it is assumed that # this function will be invoked on the target. If the file is outside a # Spack-maintained prefix, the permissions should not be modified. if os.path.islink(path): return if os.path.isdir(path): os.chmod(path, 0o755) else: os.chmod(path, 0o644)
def group_ids(uid=None): """Get group ids that a uid is a member of. Arguments: uid (int): id of user, or None for current user Returns: (list of int): gids of groups the user is a member of """ if is_windows: tty.warn("Function is not supported on Windows") return [] if uid is None: uid = getuid() user = pwd.getpwuid(uid).pw_name return [g.gr_gid for g in grp.getgrall() if user in g.gr_mem]
[docs]@system_path_filter(arg_slice=slice(1)) def chgrp(path, group, follow_symlinks=True): """Implement the bash chgrp function on a single path""" if is_windows: raise OSError("Function 'chgrp' is not supported on Windows") if isinstance(group, six.string_types): gid = grp.getgrnam(group).gr_gid else: gid = group if follow_symlinks: os.chown(path, -1, gid) else: os.lchown(path, -1, gid)
[docs]@system_path_filter(arg_slice=slice(1)) def chmod_x(entry, perms): """Implements chmod, treating all executable bits as set using the chmod utility's `+X` option. """ mode = os.stat(entry).st_mode if os.path.isfile(entry): if not mode & (stat.S_IXUSR | stat.S_IXGRP | stat.S_IXOTH): perms &= ~stat.S_IXUSR perms &= ~stat.S_IXGRP perms &= ~stat.S_IXOTH os.chmod(entry, perms)
[docs]@system_path_filter def copy_mode(src, dest): """Set the mode of dest to that of src unless it is a link. """ if os.path.islink(dest): return src_mode = os.stat(src).st_mode dest_mode = os.stat(dest).st_mode if src_mode & stat.S_IXUSR: dest_mode |= stat.S_IXUSR if src_mode & stat.S_IXGRP: dest_mode |= stat.S_IXGRP if src_mode & stat.S_IXOTH: dest_mode |= stat.S_IXOTH os.chmod(dest, dest_mode)
[docs]@system_path_filter def unset_executable_mode(path): mode = os.stat(path).st_mode mode &= ~stat.S_IXUSR mode &= ~stat.S_IXGRP mode &= ~stat.S_IXOTH os.chmod(path, mode)
[docs]@system_path_filter def copy(src, dest, _permissions=False): """Copy the file(s) *src* to the file or directory *dest*. If *dest* specifies a directory, the file will be copied into *dest* using the base filename from *src*. *src* may contain glob characters. Parameters: src (str): the file(s) to copy dest (str): the destination file or directory _permissions (bool): for internal use only Raises: IOError: if *src* does not match any files or directories ValueError: if *src* matches multiple files but *dest* is not a directory """ if _permissions: tty.debug('Installing {0} to {1}'.format(src, dest)) else: tty.debug('Copying {0} to {1}'.format(src, dest)) files = glob.glob(src) if not files: raise IOError("No such file or directory: '{0}'".format(src)) if len(files) > 1 and not os.path.isdir(dest): raise ValueError( "'{0}' matches multiple files but '{1}' is not a directory".format( src, dest)) for src in files: # Expand dest to its eventual full path if it is a directory. dst = dest if os.path.isdir(dest): dst = join_path(dest, os.path.basename(src)) shutil.copy(src, dst) if _permissions: set_install_permissions(dst) copy_mode(src, dst)
[docs]@system_path_filter def install(src, dest): """Install the file(s) *src* to the file or directory *dest*. Same as :py:func:`copy` with the addition of setting proper permissions on the installed file. Parameters: src (str): the file(s) to install dest (str): the destination file or directory Raises: IOError: if *src* does not match any files or directories ValueError: if *src* matches multiple files but *dest* is not a directory """ copy(src, dest, _permissions=True)
@system_path_filter def resolve_link_target_relative_to_the_link(link): """ os.path.isdir uses os.path.exists, which for links will check the existence of the link target. If the link target is relative to the link, we need to construct a pathname that is valid from our cwd (which may not be the same as the link's directory) """ target = os.readlink(link) if os.path.isabs(target): return target link_dir = os.path.dirname(os.path.abspath(link)) return os.path.join(link_dir, target)
[docs]@system_path_filter def copy_tree(src, dest, symlinks=True, ignore=None, _permissions=False): """Recursively copy an entire directory tree rooted at *src*. If the destination directory *dest* does not already exist, it will be created as well as missing parent directories. *src* may contain glob characters. If *symlinks* is true, symbolic links in the source tree are represented as symbolic links in the new tree and the metadata of the original links will be copied as far as the platform allows; if false, the contents and metadata of the linked files are copied to the new tree. If *ignore* is set, then each path relative to *src* will be passed to this function; the function returns whether that path should be skipped. Parameters: src (str): the directory to copy dest (str): the destination directory symlinks (bool): whether or not to preserve symlinks ignore (typing.Callable): function indicating which files to ignore _permissions (bool): for internal use only Raises: IOError: if *src* does not match any files or directories ValueError: if *src* is a parent directory of *dest* """ if _permissions: tty.debug('Installing {0} to {1}'.format(src, dest)) else: tty.debug('Copying {0} to {1}'.format(src, dest)) abs_dest = os.path.abspath(dest) if not abs_dest.endswith(os.path.sep): abs_dest += os.path.sep files = glob.glob(src) if not files: raise IOError("No such file or directory: '{0}'".format(src)) for src in files: abs_src = os.path.abspath(src) if not abs_src.endswith(os.path.sep): abs_src += os.path.sep # Stop early to avoid unnecessary recursion if being asked to copy # from a parent directory. if abs_dest.startswith(abs_src): raise ValueError('Cannot copy ancestor directory {0} into {1}'. format(abs_src, abs_dest)) mkdirp(abs_dest) for s, d in traverse_tree(abs_src, abs_dest, order='pre', follow_symlinks=not symlinks, ignore=ignore, follow_nonexisting=True): if os.path.islink(s): link_target = resolve_link_target_relative_to_the_link(s) if symlinks: target = os.readlink(s) if os.path.isabs(target): new_target = re.sub(abs_src, abs_dest, target) if new_target != target: tty.debug("Redirecting link {0} to {1}" .format(target, new_target)) target = new_target symlink(target, d) elif os.path.isdir(link_target): mkdirp(d) else: shutil.copyfile(s, d) else: if os.path.isdir(s): mkdirp(d) else: shutil.copy2(s, d) if _permissions: set_install_permissions(d) copy_mode(s, d)
[docs]@system_path_filter def install_tree(src, dest, symlinks=True, ignore=None): """Recursively install an entire directory tree rooted at *src*. Same as :py:func:`copy_tree` with the addition of setting proper permissions on the installed files and directories. Parameters: src (str): the directory to install dest (str): the destination directory symlinks (bool): whether or not to preserve symlinks ignore (typing.Callable): function indicating which files to ignore Raises: IOError: if *src* does not match any files or directories ValueError: if *src* is a parent directory of *dest* """ copy_tree(src, dest, symlinks=symlinks, ignore=ignore, _permissions=True)
[docs]@system_path_filter def is_exe(path): """True if path is an executable file.""" return os.path.isfile(path) and os.access(path, os.X_OK)
@system_path_filter def get_filetype(path_name): """ Return the output of file path_name as a string to identify file type. """ file = Executable('file') file.add_default_env('LC_ALL', 'C') output = file('-b', '-h', '%s' % path_name, output=str, error=str) return output.strip() @system_path_filter def is_nonsymlink_exe_with_shebang(path): """ Returns whether the path is an executable script with a shebang. Return False when the path is a *symlink* to an executable script. """ try: st = os.lstat(path) # Should not be a symlink if stat.S_ISLNK(st.st_mode): return False # Should be executable if not st.st_mode & (stat.S_IXUSR | stat.S_IXGRP | stat.S_IXOTH): return False # Should start with a shebang with open(path, 'rb') as f: return f.read(2) == b'#!' except (IOError, OSError): return False @system_path_filter(arg_slice=slice(1)) def chgrp_if_not_world_writable(path, group): """chgrp path to group if path is not world writable""" mode = os.stat(path).st_mode if not mode & stat.S_IWOTH: chgrp(path, group)
[docs]def mkdirp(*paths, **kwargs): """Creates a directory, as well as parent directories if needed. Arguments: paths (str): paths to create with mkdirp Keyword Aguments: mode (permission bits or None): optional permissions to set on the created directory -- use OS default if not provided group (group name or None): optional group for permissions of final created directory -- use OS default if not provided. Only used if world write permissions are not set default_perms (str or None): one of 'parents' or 'args'. The default permissions that are set for directories that are not themselves an argument for mkdirp. 'parents' means intermediate directories get the permissions of their direct parent directory, 'args' means intermediate get the same permissions specified in the arguments to mkdirp -- default value is 'args' """ mode = kwargs.get('mode', None) group = kwargs.get('group', None) default_perms = kwargs.get('default_perms', 'args') paths = path_to_os_path(*paths) for path in paths: if not os.path.exists(path): try: # detect missing intermediate folders intermediate_folders = [] last_parent = '' intermediate_path = os.path.dirname(path) while intermediate_path: if os.path.exists(intermediate_path): last_parent = intermediate_path break intermediate_folders.append(intermediate_path) intermediate_path = os.path.dirname(intermediate_path) # create folders os.makedirs(path) # leaf folder permissions if mode is not None: os.chmod(path, mode) if group: chgrp_if_not_world_writable(path, group) if mode is not None: os.chmod(path, mode) # reset sticky grp bit post chgrp # for intermediate folders, change mode just for newly created # ones and if mode_intermediate has been specified, otherwise # intermediate folders list is not populated at all and default # OS mode will be used if default_perms == 'args': intermediate_mode = mode intermediate_group = group elif default_perms == 'parents': stat_info = os.stat(last_parent) intermediate_mode = stat_info.st_mode intermediate_group = stat_info.st_gid else: msg = "Invalid value: '%s'. " % default_perms msg += "Choose from 'args' or 'parents'." raise ValueError(msg) for intermediate_path in reversed(intermediate_folders): if intermediate_mode is not None: os.chmod(intermediate_path, intermediate_mode) if intermediate_group is not None: chgrp_if_not_world_writable(intermediate_path, intermediate_group) os.chmod(intermediate_path, intermediate_mode) # reset sticky bit after except OSError as e: if e.errno != errno.EEXIST or not os.path.isdir(path): raise e elif not os.path.isdir(path): raise OSError(errno.EEXIST, "File already exists", path)
[docs]@system_path_filter def force_remove(*paths): """Remove files without printing errors. Like ``rm -f``, does NOT remove directories.""" for path in paths: try: os.remove(path) except OSError: pass
[docs]@contextmanager @system_path_filter def working_dir(dirname, **kwargs): if kwargs.get('create', False): mkdirp(dirname) orig_dir = os.getcwd() os.chdir(dirname) try: yield finally: os.chdir(orig_dir)
class CouldNotRestoreDirectoryBackup(RuntimeError): def __init__(self, inner_exception, outer_exception): self.inner_exception = inner_exception self.outer_exception = outer_exception @contextmanager @system_path_filter def replace_directory_transaction(directory_name): """Temporarily renames a directory in the same parent dir. If the operations executed within the context manager don't raise an exception, the renamed directory is deleted. If there is an exception, the move is undone. Args: directory_name (path): absolute path of the directory name Returns: temporary directory where ``directory_name`` has been moved """ # Check the input is indeed a directory with absolute path. # Raise before anything is done to avoid moving the wrong directory directory_name = os.path.abspath(directory_name) assert os.path.isdir(directory_name), 'Not a directory: ' + directory_name # Note: directory_name is normalized here, meaning the trailing slash is dropped, # so dirname is the directory's parent not the directory itself. tmpdir = tempfile.mkdtemp( dir=os.path.dirname(directory_name), prefix='.backup') # We have to jump through hoops to support Windows, since # os.rename(directory_name, tmpdir) errors there. backup_dir = os.path.join(tmpdir, 'backup') os.rename(directory_name, backup_dir) tty.debug('Directory moved [src={0}, dest={1}]'.format(directory_name, backup_dir)) try: yield backup_dir except (Exception, KeyboardInterrupt, SystemExit) as inner_exception: # Try to recover the original directory, if this fails, raise a # composite exception. try: # Delete what was there, before copying back the original content if os.path.exists(directory_name): shutil.rmtree(directory_name) os.rename(backup_dir, directory_name) except Exception as outer_exception: raise CouldNotRestoreDirectoryBackup(inner_exception, outer_exception) tty.debug('Directory recovered [{0}]'.format(directory_name)) raise else: # Otherwise delete the temporary directory shutil.rmtree(tmpdir, ignore_errors=True) tty.debug('Temporary directory deleted [{0}]'.format(tmpdir)) @system_path_filter def hash_directory(directory, ignore=[]): """Hashes recursively the content of a directory. Args: directory (path): path to a directory to be hashed Returns: hash of the directory content """ assert os.path.isdir(directory), '"directory" must be a directory!' md5_hash = hashlib.md5() # Adapted from https://stackoverflow.com/a/3431835/771663 for root, dirs, files in os.walk(directory): for name in sorted(files): filename = os.path.join(root, name) if filename not in ignore: # TODO: if caching big files becomes an issue, convert this to # TODO: read in chunks. Currently it's used only for testing # TODO: purposes. with open(filename, 'rb') as f: md5_hash.update(f.read()) return md5_hash.hexdigest() @contextmanager @system_path_filter def write_tmp_and_move(filename): """Write to a temporary file, then move into place.""" dirname = os.path.dirname(filename) basename = os.path.basename(filename) tmp = os.path.join(dirname, '.%s.tmp' % basename) with open(tmp, 'w') as f: yield f shutil.move(tmp, filename) @contextmanager @system_path_filter def open_if_filename(str_or_file, mode='r'): """Takes either a path or a file object, and opens it if it is a path. If it's a file object, just yields the file object. """ if isinstance(str_or_file, six.string_types): with open(str_or_file, mode) as f: yield f else: yield str_or_file
[docs]@system_path_filter def touch(path): """Creates an empty file at the specified path.""" if is_windows: perms = (os.O_WRONLY | os.O_CREAT) else: perms = (os.O_WRONLY | os.O_CREAT | os.O_NONBLOCK | os.O_NOCTTY) fd = None try: fd = os.open(path, perms) os.utime(path, None) finally: if fd is not None: os.close(fd)
[docs]@system_path_filter def touchp(path): """Like ``touch``, but creates any parent directories needed for the file. """ mkdirp(os.path.dirname(path)) touch(path)
[docs]@system_path_filter def join_path(prefix, *args): path = str(prefix) for elt in args: path = os.path.join(path, str(elt)) return path
[docs]@system_path_filter def ancestor(dir, n=1): """Get the nth ancestor of a directory.""" parent = os.path.abspath(dir) for i in range(n): parent = os.path.dirname(parent) return parent
@system_path_filter def get_single_file(directory): fnames = os.listdir(directory) if len(fnames) != 1: raise ValueError("Expected exactly 1 file, got {0}" .format(str(len(fnames)))) return fnames[0] @contextmanager def temp_cwd(): tmp_dir = tempfile.mkdtemp() try: with working_dir(tmp_dir): yield tmp_dir finally: shutil.rmtree(tmp_dir) @contextmanager @system_path_filter def temp_rename(orig_path, temp_path): same_path = os.path.realpath(orig_path) == os.path.realpath(temp_path) if not same_path: shutil.move(orig_path, temp_path) try: yield finally: if not same_path: shutil.move(temp_path, orig_path)
[docs]@system_path_filter def can_access(file_name): """True if we have read/write access to the file.""" return os.access(file_name, os.R_OK | os.W_OK)
[docs]@system_path_filter def traverse_tree(source_root, dest_root, rel_path='', **kwargs): """Traverse two filesystem trees simultaneously. Walks the LinkTree directory in pre or post order. Yields each file in the source directory with a matching path from the dest directory, along with whether the file is a directory. e.g., for this tree:: root/ a/ file1 file2 b/ file3 When called on dest, this yields:: ('root', 'dest') ('root/a', 'dest/a') ('root/a/file1', 'dest/a/file1') ('root/a/file2', 'dest/a/file2') ('root/b', 'dest/b') ('root/b/file3', 'dest/b/file3') Keyword Arguments: order (str): Whether to do pre- or post-order traversal. Accepted values are 'pre' and 'post' ignore (typing.Callable): function indicating which files to ignore follow_nonexisting (bool): Whether to descend into directories in ``src`` that do not exit in ``dest``. Default is True follow_links (bool): Whether to descend into symlinks in ``src`` """ follow_nonexisting = kwargs.get('follow_nonexisting', True) follow_links = kwargs.get('follow_link', False) # Yield in pre or post order? order = kwargs.get('order', 'pre') if order not in ('pre', 'post'): raise ValueError("Order must be 'pre' or 'post'.") # List of relative paths to ignore under the src root. ignore = kwargs.get('ignore', None) or (lambda filename: False) # Don't descend into ignored directories if ignore(rel_path): return source_path = os.path.join(source_root, rel_path) dest_path = os.path.join(dest_root, rel_path) # preorder yields directories before children if order == 'pre': yield (source_path, dest_path) for f in os.listdir(source_path): source_child = os.path.join(source_path, f) dest_child = os.path.join(dest_path, f) rel_child = os.path.join(rel_path, f) # Treat as a directory # TODO: for symlinks, os.path.isdir looks for the link target. If the # target is relative to the link, then that may not resolve properly # relative to our cwd - see resolve_link_target_relative_to_the_link if os.path.isdir(source_child) and ( follow_links or not os.path.islink(source_child)): # When follow_nonexisting isn't set, don't descend into dirs # in source that do not exist in dest if follow_nonexisting or os.path.exists(dest_child): tuples = traverse_tree( source_root, dest_root, rel_child, **kwargs) for t in tuples: yield t # Treat as a file. elif not ignore(os.path.join(rel_path, f)): yield (source_child, dest_child) if order == 'post': yield (source_path, dest_path)
def lexists_islink_isdir(path): """Computes the tuple (lexists(path), islink(path), isdir(path)) in a minimal number of stat calls.""" # First try to lstat, so we know if it's a link or not. try: lst = os.lstat(path) except (IOError, OSError): return False, False, False is_link = stat.S_ISLNK(lst.st_mode) # Check whether file is a dir. if not is_link: is_dir = stat.S_ISDIR(lst.st_mode) return True, is_link, is_dir # Check whether symlink points to a dir. try: st = os.stat(path) is_dir = stat.S_ISDIR(st.st_mode) except (IOError, OSError): # Dangling symlink (i.e. it lexists but not exists) is_dir = False return True, is_link, is_dir def visit_directory_tree(root, visitor, rel_path='', depth=0): """ Recurses the directory root depth-first through a visitor pattern The visitor interface is as follows: - visit_file(root, rel_path, depth) - before_visit_dir(root, rel_path, depth) -> bool if True, descends into this directory - before_visit_symlinked_dir(root, rel_path, depth) -> bool if True, descends into this directory - after_visit_dir(root, rel_path, depth) -> void only called when before_visit_dir returns True - after_visit_symlinked_dir(root, rel_path, depth) -> void only called when before_visit_symlinked_dir returns True """ dir = os.path.join(root, rel_path) if sys.version_info >= (3, 5, 0): dir_entries = sorted(os.scandir(dir), key=lambda d: d.name) # novermin else: dir_entries = os.listdir(dir) dir_entries.sort() for f in dir_entries: if sys.version_info >= (3, 5, 0): rel_child = os.path.join(rel_path, f.name) islink = f.is_symlink() # On Windows, symlinks to directories are distinct from # symlinks to files, and it is possible to create a # broken symlink to a directory (e.g. using os.symlink # without `target_is_directory=True`), invoking `isdir` # on a symlink on Windows that is broken in this manner # will result in an error. In this case we can work around # the issue by reading the target and resolving the # directory ourselves try: isdir = f.is_dir() except OSError as e: if is_windows and hasattr(e, 'winerror')\ and e.winerror == 5 and islink: # if path is a symlink, determine destination and # evaluate file vs directory link_target = resolve_link_target_relative_to_the_link(f) # link_target might be relative but # resolve_link_target_relative_to_the_link # will ensure that if so, that it is relative # to the CWD and therefore # makes sense isdir = os.path.isdir(link_target) else: raise e else: rel_child = os.path.join(rel_path, f) lexists, islink, isdir = lexists_islink_isdir(os.path.join(dir, f)) if not lexists: continue if not isdir: # handle files visitor.visit_file(root, rel_child, depth) elif not islink and visitor.before_visit_dir(root, rel_child, depth): # Handle ordinary directories visit_directory_tree(root, visitor, rel_child, depth + 1) visitor.after_visit_dir(root, rel_child, depth) elif islink and visitor.before_visit_symlinked_dir(root, rel_child, depth): # Handle symlinked directories visit_directory_tree(root, visitor, rel_child, depth + 1) visitor.after_visit_symlinked_dir(root, rel_child, depth)
[docs]@system_path_filter def set_executable(path): mode = os.stat(path).st_mode if mode & stat.S_IRUSR: mode |= stat.S_IXUSR if mode & stat.S_IRGRP: mode |= stat.S_IXGRP if mode & stat.S_IROTH: mode |= stat.S_IXOTH os.chmod(path, mode)
[docs]@system_path_filter def last_modification_time_recursive(path): path = os.path.abspath(path) times = [os.stat(path).st_mtime] times.extend(os.stat(os.path.join(root, name)).st_mtime for root, dirs, files in os.walk(path) for name in dirs + files) return max(times)
@system_path_filter def remove_empty_directories(root): """Ascend up from the leaves accessible from `root` and remove empty directories. Parameters: root (str): path where to search for empty directories """ for dirpath, subdirs, files in os.walk(root, topdown=False): for sd in subdirs: sdp = os.path.join(dirpath, sd) try: os.rmdir(sdp) except OSError: pass def readonly_file_handler(ignore_errors=False): # TODO: generate stages etc. with write permissions wherever # so this callback is no-longer required """ Generate callback for shutil.rmtree to handle permissions errors on Windows. Some files may unexpectedly lack write permissions even though they were generated by Spack on behalf of the user (e.g. the stage), so this callback will detect such cases and modify the permissions if that is the issue. For other errors, the fallback is either to raise (if ignore_errors is False) or ignore (if ignore_errors is True). This is only intended for Windows systems and will raise a separate error if it is ever invoked (by accident) on a non-Windows system. """ def error_remove_readonly(func, path, exc): if not is_windows: raise RuntimeError("This method should only be invoked on Windows") excvalue = exc[1] if is_windows and func in (os.rmdir, os.remove, os.unlink) and\ excvalue.errno == errno.EACCES: # change the file to be readable,writable,executable: 0777 os.chmod(path, stat.S_IRWXU | stat.S_IRWXG | stat.S_IRWXO) # retry func(path) elif not ignore_errors: raise return error_remove_readonly
[docs]@system_path_filter def remove_linked_tree(path): """Removes a directory and its contents. If the directory is a symlink, follows the link and removes the real directory before removing the link. This method will force-delete files on Windows Parameters: path (str): Directory to be removed """ kwargs = {'ignore_errors': True} # Windows readonly files cannot be removed by Python # directly. if is_windows: kwargs['ignore_errors'] = False kwargs['onerror'] = readonly_file_handler(ignore_errors=True) if os.path.exists(path): if os.path.islink(path): shutil.rmtree(os.path.realpath(path), **kwargs) os.unlink(path) else: shutil.rmtree(path, **kwargs)
@contextmanager @system_path_filter def safe_remove(*files_or_dirs): """Context manager to remove the files passed as input, but restore them in case any exception is raised in the context block. Args: *files_or_dirs: glob expressions for files or directories to be removed Returns: Dictionary that maps deleted files to their temporary copy within the context block. """ # Find all the files or directories that match glob_matches = [glob.glob(x) for x in files_or_dirs] # Sort them so that shorter paths like "/foo/bar" come before # nested paths like "/foo/bar/baz.yaml". This simplifies the # handling of temporary copies below sorted_matches = sorted([ os.path.abspath(x) for x in itertools.chain(*glob_matches) ], key=len) # Copy files and directories in a temporary location removed, dst_root = {}, tempfile.mkdtemp() try: for id, file_or_dir in enumerate(sorted_matches): # The glob expression at the top ensures that the file/dir exists # at the time we enter the loop. Double check here since it might # happen that a previous iteration of the loop already removed it. # This is the case, for instance, if we remove the directory # "/foo/bar" before the file "/foo/bar/baz.yaml". if not os.path.exists(file_or_dir): continue # The monotonic ID is a simple way to make the filename # or directory name unique in the temporary folder basename = os.path.basename(file_or_dir) + '-{0}'.format(id) temporary_path = os.path.join(dst_root, basename) shutil.move(file_or_dir, temporary_path) removed[file_or_dir] = temporary_path yield removed except BaseException: # Restore the files that were removed for original_path, temporary_path in removed.items(): shutil.move(temporary_path, original_path) raise
[docs]@system_path_filter def fix_darwin_install_name(path): """Fix install name of dynamic libraries on Darwin to have full path. There are two parts of this task: 1. Use ``install_name('-id', ...)`` to change install name of a single lib 2. Use ``install_name('-change', ...)`` to change the cross linking between libs. The function assumes that all libraries are in one folder and currently won't follow subfolders. Parameters: path (str): directory in which .dylib files are located """ libs = glob.glob(join_path(path, "*.dylib")) for lib in libs: # fix install name first: install_name_tool = Executable('install_name_tool') install_name_tool('-id', lib, lib) otool = Executable('otool') long_deps = otool('-L', lib, output=str).split('\n') deps = [dep.partition(' ')[0][1::] for dep in long_deps[2:-1]] # fix all dependencies: for dep in deps: for loc in libs: # We really want to check for either # dep == os.path.basename(loc) or # dep == join_path(builddir, os.path.basename(loc)), # but we don't know builddir (nor how symbolic links look # in builddir). We thus only compare the basenames. if os.path.basename(dep) == os.path.basename(loc): install_name_tool('-change', dep, loc, lib) break
[docs]def find(root, files, recursive=True): """Search for ``files`` starting from the ``root`` directory. Like GNU/BSD find but written entirely in Python. Examples: .. code-block:: console $ find /usr -name python is equivalent to: >>> find('/usr', 'python') .. code-block:: console $ find /usr/local/bin -maxdepth 1 -name python is equivalent to: >>> find('/usr/local/bin', 'python', recursive=False) Accepts any glob characters accepted by fnmatch: ========== ==================================== Pattern Meaning ========== ==================================== ``*`` matches everything ``?`` matches any single character ``[seq]`` matches any character in ``seq`` ``[!seq]`` matches any character not in ``seq`` ========== ==================================== Parameters: root (str): The root directory to start searching from files (str or Sequence): Library name(s) to search for recursive (bool): if False search only root folder, if True descends top-down from the root. Defaults to True. Returns: list: The files that have been found """ if isinstance(files, six.string_types): files = [files] if recursive: return _find_recursive(root, files) else: return _find_non_recursive(root, files)
@system_path_filter def _find_recursive(root, search_files): # The variable here is **on purpose** a defaultdict. The idea is that # we want to poke the filesystem as little as possible, but still maintain # stability in the order of the answer. Thus we are recording each library # found in a key, and reconstructing the stable order later. found_files = collections.defaultdict(list) # Make the path absolute to have os.walk also return an absolute path root = os.path.abspath(root) for path, _, list_files in os.walk(root): for search_file in search_files: matches = glob.glob(os.path.join(path, search_file)) matches = [os.path.join(path, x) for x in matches] found_files[search_file].extend(matches) answer = [] for search_file in search_files: answer.extend(found_files[search_file]) return answer @system_path_filter def _find_non_recursive(root, search_files): # The variable here is **on purpose** a defaultdict as os.list_dir # can return files in any order (does not preserve stability) found_files = collections.defaultdict(list) # Make the path absolute to have absolute path returned root = os.path.abspath(root) for search_file in search_files: matches = glob.glob(os.path.join(root, search_file)) matches = [os.path.join(root, x) for x in matches] found_files[search_file].extend(matches) answer = [] for search_file in search_files: answer.extend(found_files[search_file]) return answer # Utilities for libraries and headers
[docs]class FileList(Sequence): """Sequence of absolute paths to files. Provides a few convenience methods to manipulate file paths. """ def __init__(self, files): if isinstance(files, six.string_types): files = [files] self.files = list(dedupe(files)) @property def directories(self): """Stable de-duplication of the directories where the files reside. >>> l = LibraryList(['/dir1/liba.a', '/dir2/libb.a', '/dir1/libc.a']) >>> l.directories ['/dir1', '/dir2'] >>> h = HeaderList(['/dir1/a.h', '/dir1/b.h', '/dir2/c.h']) >>> h.directories ['/dir1', '/dir2'] Returns: list: A list of directories """ return list(dedupe( os.path.dirname(x) for x in self.files if os.path.dirname(x) )) @property def basenames(self): """Stable de-duplication of the base-names in the list >>> l = LibraryList(['/dir1/liba.a', '/dir2/libb.a', '/dir3/liba.a']) >>> l.basenames ['liba.a', 'libb.a'] >>> h = HeaderList(['/dir1/a.h', '/dir2/b.h', '/dir3/a.h']) >>> h.basenames ['a.h', 'b.h'] Returns: list: A list of base-names """ return list(dedupe(os.path.basename(x) for x in self.files)) def __getitem__(self, item): cls = type(self) if isinstance(item, numbers.Integral): return self.files[item] return cls(self.files[item]) def __add__(self, other): return self.__class__(dedupe(self.files + list(other))) def __radd__(self, other): return self.__add__(other) def __eq__(self, other): return self.files == other.files def __len__(self): return len(self.files)
[docs] def joined(self, separator=' '): return separator.join(self.files)
def __repr__(self): return self.__class__.__name__ + '(' + repr(self.files) + ')' def __str__(self): return self.joined()
[docs]class HeaderList(FileList): """Sequence of absolute paths to headers. Provides a few convenience methods to manipulate header paths and get commonly used compiler flags or names. """ # Make sure to only match complete words, otherwise path components such # as "xinclude" will cause false matches. # Avoid matching paths such as <prefix>/include/something/detail/include, # e.g. in the CUDA Toolkit which ships internal libc++ headers. include_regex = re.compile(r'(.*?)(\binclude\b)(.*)') def __init__(self, files): super(HeaderList, self).__init__(files) self._macro_definitions = [] self._directories = None @property def directories(self): """Directories to be searched for header files.""" values = self._directories if values is None: values = self._default_directories() return list(dedupe(values)) @directories.setter def directories(self, value): value = value or [] # Accept a single directory as input if isinstance(value, six.string_types): value = [value] self._directories = [path_to_os_path(os.path.normpath(x))[0] for x in value] def _default_directories(self): """Default computation of directories based on the list of header files. """ dir_list = super(HeaderList, self).directories values = [] for d in dir_list: # If the path contains a subdirectory named 'include' then stop # there and don't add anything else to the path. m = self.include_regex.match(d) value = os.path.join(*m.group(1, 2)) if m else d values.append(value) return values @property def headers(self): """Stable de-duplication of the headers. Returns: list: A list of header files """ return self.files @property def names(self): """Stable de-duplication of header names in the list without extensions >>> h = HeaderList(['/dir1/a.h', '/dir2/b.h', '/dir3/a.h']) >>> h.names ['a', 'b'] Returns: list: A list of files without extensions """ names = [] for x in self.basenames: name = x # Valid extensions include: ['.cuh', '.hpp', '.hh', '.h'] for ext in ['.cuh', '.hpp', '.hh', '.h']: i = name.rfind(ext) if i != -1: names.append(name[:i]) break else: # No valid extension, should we still include it? names.append(name) return list(dedupe(names)) @property def include_flags(self): """Include flags >>> h = HeaderList(['/dir1/a.h', '/dir1/b.h', '/dir2/c.h']) >>> h.include_flags '-I/dir1 -I/dir2' Returns: str: A joined list of include flags """ return ' '.join(['-I' + x for x in self.directories]) @property def macro_definitions(self): """Macro definitions >>> h = HeaderList(['/dir1/a.h', '/dir1/b.h', '/dir2/c.h']) >>> h.add_macro('-DBOOST_LIB_NAME=boost_regex') >>> h.add_macro('-DBOOST_DYN_LINK') >>> h.macro_definitions '-DBOOST_LIB_NAME=boost_regex -DBOOST_DYN_LINK' Returns: str: A joined list of macro definitions """ return ' '.join(self._macro_definitions) @property def cpp_flags(self): """Include flags + macro definitions >>> h = HeaderList(['/dir1/a.h', '/dir1/b.h', '/dir2/c.h']) >>> h.cpp_flags '-I/dir1 -I/dir2' >>> h.add_macro('-DBOOST_DYN_LINK') >>> h.cpp_flags '-I/dir1 -I/dir2 -DBOOST_DYN_LINK' Returns: str: A joined list of include flags and macro definitions """ cpp_flags = self.include_flags if self.macro_definitions: cpp_flags += ' ' + self.macro_definitions return cpp_flags
[docs] def add_macro(self, macro): """Add a macro definition Parameters: macro (str): The macro to add """ self._macro_definitions.append(macro)
[docs]def find_headers(headers, root, recursive=False): """Returns an iterable object containing a list of full paths to headers if found. Accepts any glob characters accepted by fnmatch: ======= ==================================== Pattern Meaning ======= ==================================== * matches everything ? matches any single character [seq] matches any character in ``seq`` [!seq] matches any character not in ``seq`` ======= ==================================== Parameters: headers (str or list): Header name(s) to search for root (str): The root directory to start searching from recursive (bool): if False search only root folder, if True descends top-down from the root. Defaults to False. Returns: HeaderList: The headers that have been found """ if isinstance(headers, six.string_types): headers = [headers] elif not isinstance(headers, Sequence): message = '{0} expects a string or sequence of strings as the ' message += 'first argument [got {1} instead]' message = message.format(find_headers.__name__, type(headers)) raise TypeError(message) # Construct the right suffix for the headers suffixes = [ # C 'h', # C++ 'hpp', 'hxx', 'hh', 'H', 'txx', 'tcc', 'icc', # Fortran 'mod', 'inc', ] # List of headers we are searching with suffixes headers = ['{0}.{1}'.format(header, suffix) for header in headers for suffix in suffixes] return HeaderList(find(root, headers, recursive))
[docs]@system_path_filter def find_all_headers(root): """Convenience function that returns the list of all headers found in the directory passed as argument. Args: root (str): directory where to look recursively for header files Returns: List of all headers found in ``root`` and subdirectories. """ return find_headers('*', root=root, recursive=True)
[docs]class LibraryList(FileList): """Sequence of absolute paths to libraries Provides a few convenience methods to manipulate library paths and get commonly used compiler flags or names """ @property def libraries(self): """Stable de-duplication of library files. Returns: list: A list of library files """ return self.files @property def names(self): """Stable de-duplication of library names in the list >>> l = LibraryList(['/dir1/liba.a', '/dir2/libb.a', '/dir3/liba.so']) >>> l.names ['a', 'b'] Returns: list: A list of library names """ names = [] for x in self.basenames: name = x if x.startswith('lib'): name = x[3:] # Valid extensions include: ['.dylib', '.so', '.a'] for ext in ['.dylib', '.so', '.a']: i = name.rfind(ext) if i != -1: names.append(name[:i]) break else: # No valid extension, should we still include it? names.append(name) return list(dedupe(names)) @property def search_flags(self): """Search flags for the libraries >>> l = LibraryList(['/dir1/liba.a', '/dir2/libb.a', '/dir1/liba.so']) >>> l.search_flags '-L/dir1 -L/dir2' Returns: str: A joined list of search flags """ return ' '.join(['-L' + x for x in self.directories]) @property def link_flags(self): """Link flags for the libraries >>> l = LibraryList(['/dir1/liba.a', '/dir2/libb.a', '/dir1/liba.so']) >>> l.link_flags '-la -lb' Returns: str: A joined list of link flags """ return ' '.join(['-l' + name for name in self.names]) @property def ld_flags(self): """Search flags + link flags >>> l = LibraryList(['/dir1/liba.a', '/dir2/libb.a', '/dir1/liba.so']) >>> l.ld_flags '-L/dir1 -L/dir2 -la -lb' Returns: str: A joined list of search flags and link flags """ return self.search_flags + ' ' + self.link_flags
[docs]def find_system_libraries(libraries, shared=True): """Searches the usual system library locations for ``libraries``. Search order is as follows: 1. ``/lib64`` 2. ``/lib`` 3. ``/usr/lib64`` 4. ``/usr/lib`` 5. ``/usr/local/lib64`` 6. ``/usr/local/lib`` Accepts any glob characters accepted by fnmatch: ======= ==================================== Pattern Meaning ======= ==================================== * matches everything ? matches any single character [seq] matches any character in ``seq`` [!seq] matches any character not in ``seq`` ======= ==================================== Parameters: libraries (str or list): Library name(s) to search for shared (bool): if True searches for shared libraries, otherwise for static. Defaults to True. Returns: LibraryList: The libraries that have been found """ if isinstance(libraries, six.string_types): libraries = [libraries] elif not isinstance(libraries, Sequence): message = '{0} expects a string or sequence of strings as the ' message += 'first argument [got {1} instead]' message = message.format(find_system_libraries.__name__, type(libraries)) raise TypeError(message) libraries_found = [] search_locations = [ '/lib64', '/lib', '/usr/lib64', '/usr/lib', '/usr/local/lib64', '/usr/local/lib', ] for library in libraries: for root in search_locations: result = find_libraries(library, root, shared, recursive=True) if result: libraries_found += result break return libraries_found
[docs]def find_libraries(libraries, root, shared=True, recursive=False): """Returns an iterable of full paths to libraries found in a root dir. Accepts any glob characters accepted by fnmatch: ======= ==================================== Pattern Meaning ======= ==================================== * matches everything ? matches any single character [seq] matches any character in ``seq`` [!seq] matches any character not in ``seq`` ======= ==================================== Parameters: libraries (str or list): Library name(s) to search for root (str): The root directory to start searching from shared (bool): if True searches for shared libraries, otherwise for static. Defaults to True. recursive (bool): if False search only root folder, if True descends top-down from the root. Defaults to False. Returns: LibraryList: The libraries that have been found """ if isinstance(libraries, six.string_types): libraries = [libraries] elif not isinstance(libraries, Sequence): message = '{0} expects a string or sequence of strings as the ' message += 'first argument [got {1} instead]' message = message.format(find_libraries.__name__, type(libraries)) raise TypeError(message) # Construct the right suffix for the library if shared: # Used on both Linux and macOS suffixes = ['so'] if sys.platform == 'darwin': # Only used on macOS suffixes.append('dylib') else: suffixes = ['a'] # List of libraries we are searching with suffixes libraries = ['{0}.{1}'.format(lib, suffix) for lib in libraries for suffix in suffixes] if not recursive: # If not recursive, look for the libraries directly in root return LibraryList(find(root, libraries, False)) # To speedup the search for external packages configured e.g. in /usr, # perform first non-recursive search in root/lib then in root/lib64 and # finally search all of root recursively. The search stops when the first # match is found. for subdir in ('lib', 'lib64'): dirname = join_path(root, subdir) if not os.path.isdir(dirname): continue found_libs = find(dirname, libraries, False) if found_libs: break else: found_libs = find(root, libraries, True) return LibraryList(found_libs)
@system_path_filter @memoized def can_access_dir(path): """Returns True if the argument is an accessible directory. Args: path: path to be tested Returns: True if ``path`` is an accessible directory, else False """ return os.path.isdir(path) and os.access(path, os.R_OK | os.X_OK) @system_path_filter @memoized def can_write_to_dir(path): """Return True if the argument is a directory in which we can write. Args: path: path to be tested Returns: True if ``path`` is an writeable directory, else False """ return os.path.isdir(path) and os.access(path, os.R_OK | os.X_OK | os.W_OK) @system_path_filter @memoized def files_in(*search_paths): """Returns all the files in paths passed as arguments. Caller must ensure that each path in ``search_paths`` is a directory. Args: *search_paths: directories to be searched Returns: List of (file, full_path) tuples with all the files found. """ files = [] for d in filter(can_access_dir, search_paths): files.extend(filter( lambda x: os.path.isfile(x[1]), [(f, os.path.join(d, f)) for f in os.listdir(d)] )) return files def is_readable_file(file_path): """Return True if the path passed as argument is readable""" return os.path.isfile(file_path) and os.access(file_path, os.R_OK) @system_path_filter def search_paths_for_executables(*path_hints): """Given a list of path hints returns a list of paths where to search for an executable. Args: *path_hints (list of paths): list of paths taken into consideration for a search Returns: A list containing the real path of every existing directory in `path_hints` and its `bin` subdirectory if it exists. """ executable_paths = [] for path in path_hints: if not os.path.isdir(path): continue path = os.path.abspath(path) executable_paths.append(path) bin_dir = os.path.join(path, 'bin') if os.path.isdir(bin_dir): executable_paths.append(bin_dir) return executable_paths @system_path_filter def search_paths_for_libraries(*path_hints): """Given a list of path hints returns a list of paths where to search for a shared library. Args: *path_hints (list of paths): list of paths taken into consideration for a search Returns: A list containing the real path of every existing directory in `path_hints` and its `lib` and `lib64` subdirectory if it exists. """ library_paths = [] for path in path_hints: if not os.path.isdir(path): continue path = os.path.abspath(path) library_paths.append(path) lib_dir = os.path.join(path, 'lib') if os.path.isdir(lib_dir): library_paths.append(lib_dir) lib64_dir = os.path.join(path, 'lib64') if os.path.isdir(lib64_dir): library_paths.append(lib64_dir) return library_paths
[docs]@system_path_filter def partition_path(path, entry=None): """ Split the prefixes of the path at the first occurrence of entry and return a 3-tuple containing a list of the prefixes before the entry, a string of the prefix ending with the entry, and a list of the prefixes after the entry. If the entry is not a node in the path, the result will be the prefix list followed by an empty string and an empty list. """ paths = prefixes(path) if entry is not None: # Derive the index of entry within paths, which will correspond to # the location of the entry in within the path. try: sep = os.sep entries = path.split(sep) if entries[0].endswith(":"): # Handle drive letters e.g. C:/ on Windows entries[0] = entries[0] + sep i = entries.index(entry) if '' in entries: i -= 1 return paths[:i], paths[i], paths[i + 1:] except ValueError: pass return paths, '', []
[docs]@system_path_filter def prefixes(path): """ Returns a list containing the path and its ancestors, top-to-bottom. The list for an absolute path will not include an ``os.sep`` entry. For example, assuming ``os.sep`` is ``/``, given path ``/ab/cd/efg`` the resulting paths will be, in order: ``/ab``, ``/ab/cd``, and ``/ab/cd/efg`` The list for a relative path starting ``./`` will not include ``.``. For example, path ``./hi/jkl/mn`` results in a list with the following paths, in order: ``./hi``, ``./hi/jkl``, and ``./hi/jkl/mn``. On Windows, paths will be normalized to use ``/`` and ``/`` will always be used as the separator instead of ``os.sep``. Parameters: path (str): the string used to derive ancestor paths Returns: A list containing ancestor paths in order and ending with the path """ if not path: return [] sep = os.sep parts = path.strip(sep).split(sep) if path.startswith(sep): parts.insert(0, sep) elif parts[0].endswith(":"): # Handle drive letters e.g. C:/ on Windows parts[0] = parts[0] + sep paths = [os.path.join(*parts[:i + 1]) for i in range(len(parts))] try: paths.remove(sep) except ValueError: pass try: paths.remove('.') except ValueError: pass return paths
@system_path_filter def md5sum(file): """Compute the MD5 sum of a file. Args: file (str): file to be checksummed Returns: MD5 sum of the file's content """ md5 = hashlib.md5() with open(file, "rb") as f: md5.update(f.read()) return md5.digest()
[docs]@system_path_filter def remove_directory_contents(dir): """Remove all contents of a directory.""" if os.path.exists(dir): for entry in [os.path.join(dir, entry) for entry in os.listdir(dir)]: if os.path.isfile(entry) or os.path.islink(entry): os.unlink(entry) else: shutil.rmtree(entry)
[docs]@contextmanager @system_path_filter def keep_modification_time(*filenames): """ Context manager to keep the modification timestamps of the input files. Tolerates and has no effect on non-existent files and files that are deleted by the nested code. Parameters: *filenames: one or more files that must have their modification timestamps unchanged """ mtimes = {} for f in filenames: if os.path.exists(f): mtimes[f] = os.path.getmtime(f) yield for f, mtime in mtimes.items(): if os.path.exists(f): os.utime(f, (os.path.getatime(f), mtime))
@contextmanager def temporary_dir(*args, **kwargs): """Create a temporary directory and cd's into it. Delete the directory on exit. Takes the same arguments as tempfile.mkdtemp() """ tmp_dir = tempfile.mkdtemp(*args, **kwargs) try: with working_dir(tmp_dir): yield tmp_dir finally: remove_directory_contents(tmp_dir)