mirror of
https://github.com/searxng/searxng.git
synced 2025-10-31 18:47:07 -04:00
89 lines
2.3 KiB
Python
89 lines
2.3 KiB
Python
# SPDX-License-Identifier: AGPL-3.0-or-later
|
|
"""Calculate mathematical expressions using ack#eval
|
|
"""
|
|
|
|
import ast
|
|
import operator
|
|
|
|
from flask_babel import gettext
|
|
from searx import settings
|
|
|
|
name = "Basic Calculator"
|
|
description = gettext("Calculate mathematical expressions via the search bar")
|
|
default_on = False
|
|
|
|
preference_section = 'general'
|
|
plugin_id = 'calculator'
|
|
|
|
operators = {
|
|
ast.Add: operator.add,
|
|
ast.Sub: operator.sub,
|
|
ast.Mult: operator.mul,
|
|
ast.Div: operator.truediv,
|
|
ast.Pow: operator.pow,
|
|
ast.BitXor: operator.xor,
|
|
ast.USub: operator.neg,
|
|
}
|
|
|
|
|
|
def _eval_expr(expr):
|
|
"""
|
|
>>> _eval_expr('2^6')
|
|
4
|
|
>>> _eval_expr('2**6')
|
|
64
|
|
>>> _eval_expr('1 + 2*3**(4^5) / (6 + -7)')
|
|
-5.0
|
|
"""
|
|
return _eval(ast.parse(expr, mode='eval').body)
|
|
|
|
|
|
def _eval(node):
|
|
if isinstance(node, ast.Constant) and isinstance(node.value, int):
|
|
return node.value
|
|
|
|
if isinstance(node, ast.BinOp):
|
|
return operators[type(node.op)](_eval(node.left), _eval(node.right))
|
|
|
|
if isinstance(node, ast.UnaryOp):
|
|
return operators[type(node.op)](_eval(node.operand))
|
|
|
|
raise TypeError(node)
|
|
|
|
|
|
def post_search(_request, search):
|
|
# don't run on public instances due to possible attack surfaces
|
|
if settings['server']['public_instance']:
|
|
return True
|
|
|
|
# only show the result of the expression on the first page
|
|
if search.search_query.pageno > 1:
|
|
return True
|
|
|
|
query = search.search_query.query
|
|
# in order to avoid DoS attacks with long expressions, ignore long expressions
|
|
if len(query) > 100:
|
|
return True
|
|
|
|
# replace commonly used math operators with their proper Python operator
|
|
query = query.replace("x", "*").replace(":", "/")
|
|
|
|
# only numbers and math operators are accepted
|
|
if any(str.isalpha(c) for c in query):
|
|
return True
|
|
|
|
# in python, powers are calculated via **
|
|
query_py_formatted = query.replace("^", "**")
|
|
try:
|
|
result = str(_eval_expr(query_py_formatted))
|
|
if result != query:
|
|
search.result_container.answers['calculate'] = {'answer': f"{query} = {result}"}
|
|
except (TypeError, SyntaxError, ArithmeticError):
|
|
pass
|
|
|
|
return True
|
|
|
|
|
|
def is_allowed():
|
|
return not settings['server']['public_instance']
|