Python os.F_OK Examples

def _popen(command, args):
    import os
    path = os.environ.get("PATH", os.defpath).split(os.pathsep)
    path.extend(('/sbin', '/usr/sbin'))
    for dir in path:
        executable = os.path.join(dir, command)
        if (os.path.exists(executable) and
            os.access(executable, os.F_OK | os.X_OK) and
            not os.path.isdir(executable)):
            break
    else:
        return None
    # LC_ALL to ensure English output, 2>/dev/null to prevent output on
    # stderr (Note: we don't have an example where the words we search for
    # are actually localized, but in theory some system could do so.)
    cmd = 'LC_ALL=C %s %s 2>/dev/null' % (executable, args)
    return os.popen(cmd) 

def is_storage_device(name):
    """Return True if the given name refers to a root device (e.g.
    "sda", "nvme0n1") as opposed to a logical partition (e.g.  "sda1",
    "nvme0n1p1"). If name is a virtual device (e.g. "loop1", "ram")
    return True.
    """
    # Readapted from iostat source code, see:
    # https://github.com/sysstat/sysstat/blob/
    #     97912938cd476645b267280069e83b1c8dc0e1c7/common.c#L208
    # Some devices may have a slash in their name (e.g. cciss/c0d0...).
    name = name.replace('/', '!')
    including_virtual = True
    if including_virtual:
        path = "/sys/block/%s" % name
    else:
        path = "/sys/block/%s/device" % name
    return os.access(path, os.F_OK) 

def get_writable_file(self,existing_only=0):
        """ Return the name of the first writable catalog file.

            Its parent directory must also be writable.  This is so that
            compiled modules can be written to the same directory.
        """
        # note: both file and its parent directory must be writeable
        if existing_only:
            files = self.get_existing_files()
        else:
            files = self.get_catalog_files()
        # filter for (file exists and is writable) OR directory is writable

        def file_test(x):
            from os import access, F_OK, W_OK
            return (access(x,F_OK) and access(x,W_OK) or
                    access(os.path.dirname(x),W_OK))
        writable = filter(file_test,files)
        if writable:
            file = writable[0]
        else:
            file = None
        return file 

def is_storage_device(name):
    """Return True if the given name refers to a root device (e.g.
    "sda", "nvme0n1") as opposed to a logical partition (e.g.  "sda1",
    "nvme0n1p1"). If name is a virtual device (e.g. "loop1", "ram")
    return True.
    """
    # Readapted from iostat source code, see:
    # https://github.com/sysstat/sysstat/blob/
    #     97912938cd476645b267280069e83b1c8dc0e1c7/common.c#L208
    # Some devices may have a slash in their name (e.g. cciss/c0d0...).
    name = name.replace('/', '!')
    including_virtual = True
    if including_virtual:
        path = "/sys/block/%s" % name
    else:
        path = "/sys/block/%s/device" % name
    return os.access(path, os.F_OK) 

def is_storage_device(name):
    """Return True if the given name refers to a root device (e.g.
    "sda", "nvme0n1") as opposed to a logical partition (e.g.  "sda1",
    "nvme0n1p1"). If name is a virtual device (e.g. "loop1", "ram")
    return True.
    """
    # Readapted from iostat source code, see:
    # https://github.com/sysstat/sysstat/blob/
    #     97912938cd476645b267280069e83b1c8dc0e1c7/common.c#L208
    # Some devices may have a slash in their name (e.g. cciss/c0d0...).
    name = name.replace('/', '!')
    including_virtual = True
    if including_virtual:
        path = "/sys/block/%s" % name
    else:
        path = "/sys/block/%s/device" % name
    return os.access(path, os.F_OK) 

def _clone_test_db(self, suffix, verbosity, keepdb=False):
        source_database_name = self.connection.settings_dict['NAME']
        target_database_name = self.get_test_db_clone_settings(suffix)['NAME']
        # Forking automatically makes a copy of an in-memory database.
        if not self.is_in_memory_db(source_database_name):
            # Erase the old test database
            if os.access(target_database_name, os.F_OK):
                if keepdb:
                    return
                if verbosity >= 1:
                    print("Destroying old test database for alias %s..." % (
                        self._get_database_display_str(verbosity, target_database_name),
                    ))
                try:
                    os.remove(target_database_name)
                except Exception as e:
                    sys.stderr.write("Got an error deleting the old test database: %s\n" % e)
                    sys.exit(2)
            try:
                shutil.copy(source_database_name, target_database_name)
            except Exception as e:
                sys.stderr.write("Got an error cloning the test database: %s\n" % e)
                sys.exit(2) 

def _popen(command, args):
    import os
    path = os.environ.get("PATH", os.defpath).split(os.pathsep)
    path.extend(('/sbin', '/usr/sbin'))
    for dir in path:
        executable = os.path.join(dir, command)
        if (os.path.exists(executable) and
            os.access(executable, os.F_OK | os.X_OK) and
            not os.path.isdir(executable)):
            break
    else:
        return None
    # LC_ALL to ensure English output, 2>/dev/null to prevent output on
    # stderr (Note: we don't have an example where the words we search for
    # are actually localized, but in theory some system could do so.)
    cmd = 'LC_ALL=C %s %s 2>/dev/null' % (executable, args)
    return os.popen(cmd) 

def __init__(self, dir, file_template=_default_file_template,
                 truncate_slug_length=40,
                 version_locations=None,
                 sourceless=False, output_encoding="utf-8"):
        self.dir = dir
        self.file_template = file_template
        self.version_locations = version_locations
        self.truncate_slug_length = truncate_slug_length or 40
        self.sourceless = sourceless
        self.output_encoding = output_encoding
        self.revision_map = revision.RevisionMap(self._load_revisions)

        if not os.access(dir, os.F_OK):
            raise util.CommandError("Path doesn't exist: %r.  Please use "
                                    "the 'init' command to create a new "
                                    "scripts folder." % dir) 

def write_script(
        scriptdir, rev_id, content, encoding='ascii', sourceless=False):
    old = scriptdir.revision_map.get_revision(rev_id)
    path = old.path

    content = textwrap.dedent(content)
    if encoding:
        content = content.encode(encoding)
    with open(path, 'wb') as fp:
        fp.write(content)
    pyc_path = util.pyc_file_from_path(path)
    if os.access(pyc_path, os.F_OK):
        os.unlink(pyc_path)
    script = Script._from_path(scriptdir, path)
    old = scriptdir.revision_map.get_revision(script.revision)
    if old.down_revision != script.down_revision:
        raise Exception("Can't change down_revision "
                        "on a refresh operation.")
    scriptdir.revision_map.add_revision(script, _replace=True)

    if sourceless:
        make_sourceless(path) 

def read_file(location):
    """Returns the contents of a file or None on error. The error is printed to
    stderr.

    Args:
        location (str): The location of the file to be read.
    """
    location = os.path.expandvars(location)

    if not os.access(location, os.F_OK):
        eprint('Configuration file', location, 'not found')
        return None

    try:
        with open(location, 'r') as file:
            return file.read()
    except PermissionError:
        eprint('Cannot read configuration file', location, '(permission)')
        return None 

def GetCacheDir(session):
    """Returns the path of a usable cache directory."""
    cache_dir = session.GetParameter("cache_dir")
    if cache_dir == None:
        return cache_dir

    cache_dir = os.path.expandvars(cache_dir)

    if not cache_dir:
        raise io_manager.IOManagerError(
            "Local profile cache is not configured - "
            "add a cache_dir parameter to ~/.rekallrc.")

    # Cache dir may be specified relative to the home directory.
    cache_dir = os.path.join(config.GetHomeDir(session), cache_dir)

    if not os.access(cache_dir, os.F_OK | os.R_OK | os.W_OK | os.X_OK):
        try:
            os.makedirs(cache_dir)
        except (IOError, OSError):
            raise io_manager.IOManagerError(
                "Unable to create or access cache directory %s" % cache_dir)

    return cache_dir 

def setTmpDir(self):
        """Set the tmpDir attribute to a reasonnable location for a temporary
        directory"""
        if os.name != 'nt':
            # On unix use /tmp by default
            self.tmpDir = os.environ.get("TMPDIR", "/tmp")
            self.tmpDir = os.environ.get("TMP", self.tmpDir)
        else:
            # On Windows use the current directory
            self.tmpDir = os.environ.get("TMPDIR", "")
            self.tmpDir = os.environ.get("TMP", self.tmpDir)
            self.tmpDir = os.environ.get("TEMP", self.tmpDir)
        if not os.path.isdir(self.tmpDir):
            self.tmpDir = ""
        elif not os.access(self.tmpDir, os.F_OK + os.W_OK):
            self.tmpDir = "" 

def check_permissions(self, device_id):
        if not os.access(self.devices[device_id]['path'], os.F_OK | os.R_OK | os.X_OK):
            return False
        if not self.check_file_permissions(self.device_file(device_id, 'alternate_modes')):
            return False
        if not self.check_file_permissions(self.device_file(device_id, 'range')):
            return False
        if not self.check_file_permissions(self.device_file(device_id, 'combine_pedals')):
            return False
        if not self.check_file_permissions(self.device_file(device_id, 'gain')):
            return False
        if not self.check_file_permissions(self.device_file(device_id, 'autocenter')):
            return False
        if not self.check_file_permissions(self.device_file(device_id, 'spring_level')):
            return False
        if not self.check_file_permissions(self.device_file(device_id, 'damper_level')):
            return False
        if not self.check_file_permissions(self.device_file(device_id, 'friction_level')):
            return False
        if not self.check_file_permissions(self.device_file(device_id, 'ffb_leds')):
            return False
        if not self.check_file_permissions(self.device_file(device_id, 'peak_ffb_level')):
            return False
        return True 

def _create_test_db(self, verbosity, autoclobber, keepdb=False):
        test_database_name = self._get_test_db_name()

        if keepdb:
            return test_database_name
        if not self.connection.is_in_memory_db(test_database_name):
            # Erase the old test database
            if verbosity >= 1:
                print("Destroying old test database '%s'..." % self.connection.alias)
            if os.access(test_database_name, os.F_OK):
                if not autoclobber:
                    confirm = input(
                        "Type 'yes' if you would like to try deleting the test "
                        "database '%s', or 'no' to cancel: " % test_database_name
                    )
                if autoclobber or confirm == 'yes':
                    try:
                        os.remove(test_database_name)
                    except Exception as e:
                        sys.stderr.write("Got an error deleting the old test database: %s\n" % e)
                        sys.exit(2)
                else:
                    print("Tests cancelled.")
                    sys.exit(1)
        return test_database_name 

def can_write_dir(path):
  """Determines if the directory at path can be written to by the current process.

  If the directory doesn't exist, determines if it can be created and thus written to.

  N.B.: This is a best-effort check only that uses permission heuristics and does not actually test
  that the directory can be written to with and writes.

  :param str path: The directory path to test.
  :return: `True` if the given path is a directory that can be written to by the current process.
  :rtype boo:
  """
  while not os.access(path, os.F_OK):
    parent_path = os.path.dirname(path)
    if not parent_path or (parent_path == path):
      # We've recursed up to the root without success, which shouldn't happen,
      return False
    path = parent_path
  return os.path.isdir(path) and os.access(path, os.R_OK | os.W_OK | os.X_OK) 

def _clean_check(cmd, target):
    """
    Run the command to download target. If the command fails, clean up before
    re-raising the error.
    """
    try:
        subprocess.check_call(cmd)
    except subprocess.CalledProcessError:
        if os.access(target, os.F_OK):
            os.unlink(target)
        raise 

def _clean_check(cmd, target):
    """
    Run the command to download target. If the command fails, clean up before
    re-raising the error.
    """
    try:
        subprocess.check_call(cmd)
    except subprocess.CalledProcessError:
        if os.access(target, os.F_OK):
            os.unlink(target)
        raise 

def _clean_check(cmd, target):
    """
    Run the command to download target. If the command fails, clean up before
    re-raising the error.
    """
    try:
        subprocess.check_call(cmd)
    except subprocess.CalledProcessError:
        if os.access(target, os.F_OK):
            os.unlink(target)
        raise 

def scp_pull_file(client, client_ftp, transfer_file, local_dir, remote_dir,
    CLOBBER=False, VERBOSE=False, LIST=False, MODE=0o775):
    #-- local and remote versions of file
    local_file = os.path.join(local_dir,transfer_file)
    remote_file = posixpath.join(remote_dir,transfer_file)
    #-- check if remote file is newer than the local file
    TEST = False
    OVERWRITE = 'clobber'
    if os.access(local_file, os.F_OK):
        local_mtime = os.stat(local_file).st_mtime
        remote_mtime = client_ftp.stat(remote_file).st_mtime
        #-- if remote file is newer: overwrite the local file
        if (even(remote_mtime) > even(local_mtime)):
            TEST = True
            OVERWRITE = 'overwrite'
    else:
        TEST = True
        OVERWRITE = 'new'
    #-- if file does not exist locally, is to be overwritten, or CLOBBER is set
    if TEST or CLOBBER:
        if VERBOSE or LIST:
            print('{0} --> '.format(remote_file))
            print('\t{0} ({1})\n'.format(local_file,OVERWRITE))
        #-- if not only listing files
        if not LIST:
            #-- copy local files from remote server
            with scp.SCPClient(client.get_transport(), socket_timeout=20) as s:
                s.get(remote_file, local_path=local_file, preserve_times=True)
            #-- change the permissions level of the transported file to MODE
            os.chmod(local_file, MODE)

#-- PURPOSE: rounds a number to an even number less than or equal to original 

def test_find_mac(self):
        data = '''\

fake hwaddr
cscotun0  Link encap:UNSPEC  HWaddr 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00
eth0      Link encap:Ethernet  HWaddr 12:34:56:78:90:ab
'''
        def mock_popen(cmd):
            return io.BytesIO(data)

        path = os.environ.get("PATH", os.defpath).split(os.pathsep)
        path.extend(('/sbin', '/usr/sbin'))
        for dir in path:
            executable = os.path.join(dir, 'ifconfig')
            if (os.path.exists(executable) and
                os.access(executable, os.F_OK | os.X_OK) and
                not os.path.isdir(executable)):
                break
        else:
            self.skipTest('requires ifconfig')

        with test_support.swap_attr(os, 'popen', mock_popen):
            mac = uuid._find_mac(
                command='ifconfig',
                args='',
                hw_identifiers=['hwaddr'],
                get_index=lambda x: x + 1,
            )
            self.assertEqual(mac, 0x1234567890ab) 

def bootstrap_config(config_file=DEFAULT_CONFIG_FILE, keychain_file=DEFAULT_KEYCHAIN_FILE, base_dir=None):
    if not base_dir:
        base_dir = os.path.expanduser('~')
    if os.path.isdir(base_dir) and os.access(base_dir, os.F_OK | os.R_OK | os.W_OK | os.X_OK):
        if not os.path.isfile(config_file):
            write_config(config_file=config_file)
            print("Created default configuration file: %s" % config_file)
        else:
            upgrade_config(config_file)
        if not os.path.isfile(keychain_file):
            write_keychain(keychain_file=keychain_file)
            print("Created default keychain file: %s" % keychain_file) 

def _clean_check(cmd, target):
    """
    Run the command to download target. If the command fails, clean up before
    re-raising the error.
    """
    try:
        subprocess.check_call(cmd)
    except subprocess.CalledProcessError:
        if os.access(target, os.F_OK):
            os.unlink(target)
        raise 

def check_file_permissions(self, path):
        if path == None:
            return True
        if not os.access(path, os.F_OK):
            return True
        if os.access(path, os.R_OK | os.W_OK):
            return True
        return False 

def access(self, mode):
            """ Return true if current user has access to this path.

            mode - One of the constants os.F_OK, os.R_OK, os.W_OK, os.X_OK
            """
            return os.access(self, mode) 

def has_msys():
    _msysdll = "msys-1.0.dll"
    for _path in os.environ["PATH"].split(os.pathsep):
        currpath = os.path.join(_path, _msysdll)
        if os.path.isfile(currpath) and os.access(currpath, os.F_OK):
            return _path
    return None 

def _create_test_db(self, verbosity, autoclobber, keepdb=False):
        test_database_name = self._get_test_db_name()

        if keepdb:
            return test_database_name
        if not self.is_in_memory_db(test_database_name):
            # Erase the old test database
            if verbosity >= 1:
                print("Destroying old test database for alias %s..." % (
                    self._get_database_display_str(verbosity, test_database_name),
                ))
            if os.access(test_database_name, os.F_OK):
                if not autoclobber:
                    confirm = input(
                        "Type 'yes' if you would like to try deleting the test "
                        "database '%s', or 'no' to cancel: " % test_database_name
                    )
                if autoclobber or confirm == 'yes':
                    try:
                        os.remove(test_database_name)
                    except Exception as e:
                        sys.stderr.write("Got an error deleting the old test database: %s\n" % e)
                        sys.exit(2)
                else:
                    print("Tests cancelled.")
                    sys.exit(1)
        return test_database_name 

def checked_device_file(self, device_id, filename):
        path = self.device_file(device_id, filename)
        if not os.access(path, os.F_OK | os.R_OK | os.W_OK):
            return None
        return path 

def filter_compiledir(path):
    # Expand '~' in path
    path = os.path.expanduser(path)
    # Turn path into the 'real' path. This ensures that:
    #   1. There is no relative path, which would fail e.g. when trying to
    #      import modules from the compile dir.
    #   2. The path is stable w.r.t. e.g. symlinks (which makes it easier
    #      to re-use compiled modules).
    path = os.path.realpath(path)
    if os.access(path, os.F_OK):  # Do it exist?
        if not os.access(path, os.R_OK | os.W_OK | os.X_OK):
            # If it exist we need read, write and listing access
            raise ValueError(
                "compiledir '%s' exists but you don't have read, write"
                " or listing permissions." % path)
    else:
        try:
            os.makedirs(path, 0o770)  # read-write-execute for user and group
        except OSError as e:
            # Maybe another parallel execution of theano was trying to create
            # the same directory at the same time.
            if e.errno != errno.EEXIST:
                raise ValueError(
                    "Unable to create the compiledir directory"
                    " '%s'. Check the permissions." % path)

    # PROBLEM: sometimes the initial approach based on
    # os.system('touch') returned -1 for an unknown reason; the
    # alternate approach here worked in all cases... it was weird.
    # No error should happen as we checked the permissions.
    init_file = os.path.join(path, '__init__.py')
    if not os.path.exists(init_file):
        try:
            open(init_file, 'w').close()
        except IOError as e:
            if os.path.exists(init_file):
                pass  # has already been created
            else:
                e.args += ('%s exist? %s' % (path, os.path.exists(path)),)
                raise
    return path 

def _clean_check(cmd, target):
    """
    Run the command to download target. If the command fails, clean up before
    re-raising the error.
    """
    try:
        subprocess.check_call(cmd)
    except subprocess.CalledProcessError:
        if os.access(target, os.F_OK):
            os.unlink(target)
        raise 

def exists(fileName):
        return os.access(fileName, os.F_OK)