# -*- coding: utf-8 -*-
"""Text parser plugin for ZSH extended_history files.
References:
https://zsh.sourceforge.io/Doc/Release/Options.html#index-EXTENDEDHISTORY
"""
import pyparsing
from dfdatetime import posix_time as dfdatetime_posix_time
from plaso.containers import events
from plaso.lib import errors
from plaso.parsers import text_parser
from plaso.parsers.text_plugins import interface
[docs]
class ZshHistoryEventData(events.EventData):
"""ZSH history event data.
Attributes:
command (str): command that was run.
elapsed_seconds (int): number of seconds that the command took to execute.
last_written_time (dfdatetime.DateTimeValues): entry last written date and
time.
"""
DATA_TYPE = 'shell:zsh:history'
[docs]
def __init__(self):
"""Initializes event data."""
super(ZshHistoryEventData, self).__init__(data_type=self.DATA_TYPE)
self.command = None
self.elapsed_seconds = None
self.last_written_time = None
[docs]
class ZshExtendedHistoryTextPlugin(interface.TextPluginWithLineContinuation):
"""Text parser plugin for ZSH extended history files."""
NAME = 'zsh_extended_history'
DATA_FORMAT = 'ZSH extended history file'
ENCODING = 'utf-8'
_INTEGER = pyparsing.Word(pyparsing.nums).set_parse_action(
lambda tokens: int(tokens[0], 10))
_END_OF_LINE = pyparsing.Suppress(pyparsing.LineEnd())
_LOG_LINE_START = (
pyparsing.Literal(':') + _INTEGER.set_results_name('timestamp') +
pyparsing.Literal(':') + _INTEGER.set_results_name('elapsed_seconds') +
pyparsing.Literal(';'))
_LOG_LINE = (
_LOG_LINE_START + pyparsing.restOfLine().set_results_name('command') +
_END_OF_LINE)
_LINE_STRUCTURES = [('log_line', _LOG_LINE)]
# Using a regular expression here to ensure whitespace is matched accordingly.
VERIFICATION_GRAMMAR = (
pyparsing.Regex(r': [0-9]+:[0-9]+;\S') + pyparsing.restOfLine() +
_END_OF_LINE)
[docs]
def __init__(self):
"""Initializes a text parser plugin."""
super(ZshExtendedHistoryTextPlugin, self).__init__()
self._command_lines = None
self._event_data = None
def _ParseFinalize(self, parser_mediator):
"""Finalizes parsing.
Args:
parser_mediator (ParserMediator): mediates interactions between parsers
and other components, such as storage and dfVFS.
"""
if self._event_data:
self._event_data.command = ' '.join(self._command_lines)
self._command_lines = []
parser_mediator.ProduceEventData(self._event_data)
self._event_data = None
def _ParseLogline(self, structure):
"""Parses a log line.
Args:
structure (pyparsing.ParseResults): structure of tokens derived from
a line of a text file.
"""
timestamp = self._GetValueFromStructure(structure, 'timestamp')
command = self._GetValueFromStructure(structure, 'command')
event_data = ZshHistoryEventData()
event_data.elapsed_seconds = self._GetValueFromStructure(
structure, 'elapsed_seconds')
event_data.last_written_time = dfdatetime_posix_time.PosixTime(
timestamp=timestamp)
self._event_data = event_data
self._command_lines = [command]
def _ParseRecord(self, parser_mediator, key, structure):
"""Parses a pyparsing structure.
Args:
parser_mediator (ParserMediator): mediates interactions between parsers
and other components, such as storage and dfVFS.
key (str): name of the parsed structure.
structure (pyparsing.ParseResults): tokens from a parsed log line.
Raises:
ParseError: if the structure cannot be parsed.
"""
if key == '_line_continuation':
command = structure.replace('\n', ' ').strip()
self._command_lines.append(command)
else:
if self._event_data:
self._event_data.command = ' '.join(self._command_lines)
parser_mediator.ProduceEventData(self._event_data)
self._ParseLogline(structure)
def _ResetState(self):
"""Resets stored values."""
self._command_lines = []
self._event_data = None
[docs]
def CheckRequiredFormat(self, parser_mediator, text_reader):
"""Check if the log record has the minimal structure required by the parser.
Args:
parser_mediator (ParserMediator): mediates interactions between parsers
and other components, such as storage and dfVFS.
text_reader (EncodedTextReader): text reader.
Returns:
bool: True if this is the correct plugin, False otherwise.
"""
try:
self._VerifyString(text_reader.lines)
except errors.ParseError:
return False
self._ResetState()
return True
text_parser.TextLogParser.RegisterPlugin(ZshExtendedHistoryTextPlugin)