80 lines
2.4 KiB
Python
80 lines
2.4 KiB
Python
import bashlex
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from . import bashlex_eval
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class EnvironmentParseError(Exception):
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pass
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def parse_environment(env_string):
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env_items = split_env_items(env_string)
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assignments = [EnvironmentAssignment(item) for item in env_items]
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return ParsedEnvironment(assignments=assignments)
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def split_env_items(env_string):
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'''Splits space-separated variable assignments into a list of individual assignments.
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>>> split_env_items('VAR=abc')
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['VAR=abc']
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>>> split_env_items('VAR="a string" THING=3')
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['VAR="a string"', 'THING=3']
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>>> split_env_items('VAR="a string" THING=\\'single "quotes"\\'')
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['VAR="a string"', 'THING=\\'single "quotes"\\'']
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>>> split_env_items('VAR="dont \\\\"forget\\\\" about backslashes"')
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['VAR="dont \\\\"forget\\\\" about backslashes"']
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'''
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return list(bashlex.split(env_string))
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class EnvironmentAssignment(object):
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def __init__(self, assignment):
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name, equals, value = assignment.partition('=')
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if not equals:
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raise EnvironmentParseError(assignment)
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self.name = name
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self.value = value
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if value:
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command_node = bashlex.parsesingle(value)
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if len(command_node.parts) != 1:
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raise ValueError('"%s" has too many parts' % value)
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self.value_word_node = command_node.parts[0]
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else:
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self.value_word_node = None
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def evaluated_value(self, environment):
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'''Returns the value of this assignment, as evaluated in the environment'''
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if self.value_word_node:
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return bashlex_eval.evaluate_node(self.value_word_node, environment=environment)
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else:
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return ''
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def as_shell_assignment(self):
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return 'export %s=%s' % (self.name, self.value)
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def __repr__(self):
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return '%s=%s' % (self.name, self.value)
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class ParsedEnvironment(object):
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def __init__(self, assignments):
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self.assignments = assignments
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def as_dictionary(self, prev_environment):
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environment = prev_environment.copy()
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for assignment in self.assignments:
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value = assignment.evaluated_value(environment=environment)
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environment[assignment.name] = value
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return environment
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def as_shell_commands(self):
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return [a.as_shell_assignment() for a in self.assignments]
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def __repr__(self):
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return 'ParsedEnvironment(%r)' % [repr(a) for a in self.assignments]
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