How to use the salt.utils.files.fopen function in salt

def test_get_url_file(self):
        '''
        cp.get_url with file:// source given
        '''
        tgt = ''
        src = os.path.join('file://', paths.FILES, 'file', 'base', 'file.big')
        ret = self.run_function(
            'cp.get_url',
            [
                src,
                tgt,
            ])
        with salt.utils.files.fopen(ret, 'r') as scene:
            data = salt.utils.stringutils.to_unicode(scene.read())
        self.assertIn('KNIGHT:  They\'re nervous, sire.', data)
        self.assertNotIn('bacon', data)

def test_autosign_grains_accept(self):
        grain_file_path = os.path.join(self.autosign_grains_dir, 'test_grain')
        with salt.utils.files.fopen(grain_file_path, 'w') as f:
            f.write(salt.utils.stringutils.to_str('#invalid_value\ncheese'))
        os.chmod(grain_file_path, self.autosign_file_permissions)

        self.run_call('test.ping -l quiet')  # get minon to try to authenticate itself again
        self.assertIn('minion', self.run_key('-l acc'))

'''
        Test the (mis-)behaviour of file.replace as described in #18612:

        Using 'prepend_if_not_found' or 'append_if_not_found' resulted in
        an infinitely growing file as 'file.replace' didn't check beforehand
        whether the changes had already been done to the file

        # Case description:

        The tested file contains one commented line
        The commented line should be uncommented in the end, nothing else should change
        '''
        test_name = 'test_replace_issue_18612'
        path_test = os.path.join(TMP, test_name)

        with salt.utils.files.fopen(path_test, 'w+') as fp_test_:
            fp_test_.write('# en_US.UTF-8')

        ret = []
        for x in range(0, 3):
            ret.append(self.run_state('file.replace',
                name=path_test, pattern='^# en_US.UTF-8$', repl='en_US.UTF-8', append_if_not_found=True))

        try:
            # ensure, the number of lines didn't change, even after invoking 'file.replace' 3 times
            with salt.utils.files.fopen(path_test, 'r') as fp_test_:
                self.assertTrue((sum(1 for _ in fp_test_) == 1))

            # ensure, the replacement succeeded
            with salt.utils.files.fopen(path_test, 'r') as fp_test_:
                self.assertTrue(fp_test_.read().startswith('en_US.UTF-8'))

self.assertTrue(
            self.run_function('hosts.add_host', ['192.168.1.2', 'oldhost2'])
        )
        self.assertTrue(
            self.run_function(
                'hosts.add_host', ['192.168.1.2', 'host2-reorder']
            )
        )
        self.assertTrue(
            self.run_function(
                'hosts.add_host', ['192.168.1.1', 'host1-reorder']
            )
        )

        # now read the lines and ensure they're formatted correctly
        with salt.utils.files.fopen(HFN, 'r') as fp_:
            lines = salt.utils.stringutils.to_unicode(fp_.read()).splitlines()
        self.assertEqual(lines, [
            '192.168.1.3\t\thost3.fqdn.com',
            '192.168.1.1\t\thost1.fqdn.com host1 host1-reorder',
            '192.168.1.2\t\thost2.fqdn.com host2 oldhost2 host2-reorder',
        ])

log.debug('counting strings in dict val: %s', val)
                    _count_strings(key)
                    _count_strings(val)
            elif isinstance(config, list):
                log.debug('counting strings in list: %s', config)
                for item in config:
                    _count_strings(item)
            else:
                if isinstance(config, six.string_types):
                    if isinstance(config, six.text_type):
                        tally['unicode'] = tally.get('unicode', 0) + 1
                    else:
                        # We will never reach this on PY3
                        tally.setdefault('non_unicode', []).append(config)

        with salt.utils.files.fopen(fpath, 'w') as wfh:
            wfh.write(textwrap.dedent('''
                foo: bar
                mylist:
                  - somestring
                  - 9
                  - 123.456
                  - True
                  - nested:
                    - key: val
                    - nestedlist:
                      - foo
                      - bar
                      - baz
                mydict:
                  - somestring: 9
                  - 123.456: 789

)
                )
                for subdir_file in SUBDIR_FILES:
                    cache_loc = os.path.join(fileclient.__opts__['cachedir'],
                                             'files',
                                             saltenv,
                                             SUBDIR,
                                             subdir_file)
                    # Double check that the content of the cached file
                    # identifies it as being from the correct saltenv. The
                    # setUp function creates the file with the name of the
                    # saltenv mentioned in the file, so a simple 'in' check is
                    # sufficient here. If opening the file raises an exception,
                    # this is a problem, so we are not catching the exception
                    # and letting it be raised so that the test fails.
                    with salt.utils.files.fopen(cache_loc) as fp_:
                        content = fp_.read()
                    log.debug('cache_loc = %s', cache_loc)
                    log.debug('content = %s', content)
                    self.assertTrue(subdir_file in content)
                    self.assertTrue(SUBDIR in content)
                    self.assertTrue(saltenv in content)

with salt.utils.files.fopen('baz.txt', mode) as self.fh3:
                    size = 20
                    result = self.fh3.read(size)
                    assert result == answers[0][:size], result
                    # Use .readline() to read the remainder of the line
                    result = self.fh3.readline()
                    assert result == answers[0][size:], result
                    # Read and check the other two lines
                    result = self.fh3.readline()
                    assert result == answers[1], result
                    result = self.fh3.readline()
                    assert result == answers[2], result

                try:
                    with salt.utils.files.fopen('helloworld.txt'):
                        raise Exception('No globs should have matched')
                except IOError:
                    # An IOError is expected here
                    pass

def _get_local_groups(self):
        '''
        Return all known local groups to the system.
        '''
        groups = dict()
        path = '/etc/group'
        with salt.utils.files.fopen(path, 'r') as fp_:
            for line in fp_:
                line = line.strip()
                if ':' not in line:
                    continue
                name, password, gid, users = line.split(':')
                groups[name] = {
                    'gid': gid,
                }

                if users:
                    groups[name]['users'] = users.split(',')

        return groups

except StopIteration:
                raise SaltInvocationError(
                    'unable to find keygrip associated with fingerprint \'{0}\' for keyid \'{1}\''
                    .format(local_key_fingerprint, local_keyid)
                )

        if local_keyid is None:
            raise SaltInvocationError(
                'The key ID \'{0}\' was not found in GnuPG keyring at \'{1}\''
                .format(keyid, gnupghome)
            )

        _check_repo_sign_utils_support('debsign')

        if older_gnupg:
            with salt.utils.files.fopen(gpg_info_file, 'r') as fow:
                gpg_raw_info = fow.readlines()

            for gpg_info_line in gpg_raw_info:
                gpg_info_line = salt.utils.stringutils.to_unicode(gpg_info_line)
                gpg_info = gpg_info_line.split('=')
                env[gpg_info[0]] = gpg_info[1]
                break
        else:
            with salt.utils.files.fopen(gpg_tty_info_file, 'r') as fow:
                gpg_raw_info = fow.readlines()

            for gpg_tty_info_line in gpg_raw_info:
                gpg_tty_info_line = salt.utils.stringutils.to_unicode(gpg_tty_info_line)
                gpg_tty_info = gpg_tty_info_line.split('=')
                env[gpg_tty_info[0]] = gpg_tty_info[1]
                break

ret_val = []
    files = []
    conf_dirs = ['/etc/xbps.d/', '/usr/share/xbps.d/']
    name_glob = '*.conf'
    # Matches a line where first printing is "repository" and there is an equals
    # sign before the repo, an optional forwardslash at the end of the repo name,
    # and it's possible for there to be a comment after repository=repo
    regex = re.compile(r'\s*repository\s*=\s*'+repo+r'/?\s*(#.*)?$')

    for cur_dir in conf_dirs:
        files.extend(glob.glob(cur_dir+name_glob))

    for filename in files:
        write_buff = []
        with salt.utils.files.fopen(filename, 'r') as cur_file:
            for line in cur_file:
                if regex.match(salt.utils.stringutils.to_unicode(line)):
                    ret_val.append(filename)
                else:
                    write_buff.append(line)
        if rewrite and filename in ret_val:
            if len(write_buff) > 0:
                with salt.utils.files.fopen(filename, 'w') as rewrite_file:
                    rewrite_file.writelines(write_buff)
            else:  # Prune empty files
                os.remove(filename)

    return ret_val