├── setup.cfg ├── docker-entrypoint.sh ├── Dockerfile.pypy3 ├── examples ├── simple.py ├── function.py ├── arguments.py └── nested.py ├── Dockerfile.python3 ├── Dockerfile.python2.7 ├── runtests.sh ├── setup.py ├── .gitignore ├── README.md ├── test.py ├── sysdig_tracers.py └── LICENSE.txt /setup.cfg: -------------------------------------------------------------------------------- 1 | [metadata] 2 | description-file = README.md 3 | -------------------------------------------------------------------------------- /docker-entrypoint.sh: -------------------------------------------------------------------------------- 1 | #!/bin/sh 2 | rm -fr __pycache__/ 3 | py.test $* test.py 4 | -------------------------------------------------------------------------------- /Dockerfile.pypy3: -------------------------------------------------------------------------------- 1 | FROM pypy:3-slim 2 | RUN pip install pytest 3 | WORKDIR /tracer-py 4 | ADD docker-entrypoint.sh / 5 | ENTRYPOINT [ "/docker-entrypoint.sh" ] 6 | -------------------------------------------------------------------------------- /examples/simple.py: -------------------------------------------------------------------------------- 1 | from sysdig_tracers import Tracer 2 | import time 3 | 4 | while True: 5 | with Tracer(): 6 | print "Hello World" 7 | time.sleep(0.5) -------------------------------------------------------------------------------- /Dockerfile.python3: -------------------------------------------------------------------------------- 1 | FROM python:3-alpine 2 | RUN pip install pytest 3 | WORKDIR /tracer-py 4 | ADD docker-entrypoint.sh / 5 | ENTRYPOINT [ "/docker-entrypoint.sh" ] 6 | -------------------------------------------------------------------------------- /Dockerfile.python2.7: -------------------------------------------------------------------------------- 1 | FROM python:2.7-alpine 2 | RUN pip install pytest 3 | WORKDIR /tracer-py 4 | ADD docker-entrypoint.sh / 5 | ENTRYPOINT [ "/docker-entrypoint.sh" ] 6 | -------------------------------------------------------------------------------- /examples/function.py: -------------------------------------------------------------------------------- 1 | from sysdig_tracers import Tracer 2 | import time 3 | 4 | @Tracer 5 | def myprinter(): 6 | print "Hello World" 7 | 8 | while True: 9 | myprinter() 10 | time.sleep(0.5) -------------------------------------------------------------------------------- /runtests.sh: -------------------------------------------------------------------------------- 1 | #!/bin/bash 2 | set -ex 3 | for dockerfile in Dockerfile.*; do 4 | python_version=`echo $dockerfile|cut -d "." -f2` 5 | docker build -t tracer-py-${python_version} -f ${dockerfile} . 6 | docker run -it --rm -v $PWD:/tracer-py tracer-py-${python_version} $* 7 | done 8 | -------------------------------------------------------------------------------- /examples/arguments.py: -------------------------------------------------------------------------------- 1 | from sysdig_tracers import Tracer, Args, ReturnValue 2 | 3 | @Tracer(enter_args={"n": Args(0)}, exit_args={"ret": ReturnValue}) 4 | def factorial(n): 5 | if n == 1: 6 | return 1 7 | else: 8 | return n * factorial(n-1) 9 | 10 | print factorial(10) 11 | -------------------------------------------------------------------------------- /setup.py: -------------------------------------------------------------------------------- 1 | from setuptools import setup 2 | 3 | setup(name='sysdig-tracers', 4 | version='0.1.2', 5 | description='Python library to emit Sysdig tracers', 6 | url='http://github.com/draios/tracers-py', 7 | author='sysdig Inc.', 8 | author_email='info@sysdig.com', 9 | license='MIT', 10 | py_modules=['sysdig_tracers'], 11 | zip_safe=False) 12 | -------------------------------------------------------------------------------- /examples/nested.py: -------------------------------------------------------------------------------- 1 | from sysdig_tracers import Tracer 2 | import time 3 | import random 4 | 5 | def noiseSleep(base): 6 | return time.sleep(base + random.random() / 10) 7 | 8 | while True: 9 | with Tracer("worker") as t: 10 | print("Hello World") 11 | noiseSleep(0.1) 12 | with t.span("read"): 13 | noiseSleep(0.2) 14 | with t.span("parse"): 15 | noiseSleep(0.3) 16 | with t.span("write"): 17 | noiseSleep(0.4) 18 | -------------------------------------------------------------------------------- /.gitignore: -------------------------------------------------------------------------------- 1 | # Byte-compiled / optimized / DLL files 2 | __pycache__/ 3 | *.py[cod] 4 | *$py.class 5 | 6 | # C extensions 7 | *.so 8 | 9 | # Distribution / packaging 10 | .Python 11 | env/ 12 | build/ 13 | develop-eggs/ 14 | dist/ 15 | downloads/ 16 | eggs/ 17 | .eggs/ 18 | lib/ 19 | lib64/ 20 | parts/ 21 | sdist/ 22 | var/ 23 | *.egg-info/ 24 | .installed.cfg 25 | *.egg 26 | 27 | # PyInstaller 28 | # Usually these files are written by a python script from a template 29 | # before PyInstaller builds the exe, so as to inject date/other infos into it. 30 | *.manifest 31 | *.spec 32 | 33 | # Installer logs 34 | pip-log.txt 35 | pip-delete-this-directory.txt 36 | 37 | # Unit test / coverage reports 38 | htmlcov/ 39 | .tox/ 40 | .coverage 41 | .coverage.* 42 | .cache 43 | nosetests.xml 44 | coverage.xml 45 | *,cover 46 | .hypothesis/ 47 | 48 | # Translations 49 | *.mo 50 | *.pot 51 | 52 | # Django stuff: 53 | *.log 54 | 55 | # Sphinx documentation 56 | docs/_build/ 57 | 58 | # PyBuilder 59 | target/ 60 | 61 | #Ipython Notebook 62 | .ipynb_checkpoints 63 | -------------------------------------------------------------------------------- /README.md: -------------------------------------------------------------------------------- 1 | # tracers-py 2 | Python library to easy emit Sysdig tracers 3 | 4 | # Install 5 | 6 | This library supports python 2.7 and 3, it also works on pypy 3 as well. To install it, just type: 7 | 8 | ``` 9 | pip install sysdig-tracers 10 | ``` 11 | 12 | Install also [sysdig](https://github.com/draios/sysdig/wiki/How-to-Install-Sysdig-for-Linux) to read trace data and correlate them. 13 | 14 | # Usage 15 | 16 | Using this library is pretty easy, just wrap your code in a `with` statement: 17 | 18 | ```python 19 | from sysdig_tracers import Tracer 20 | import time 21 | 22 | while True: 23 | with Tracer(): 24 | print "Hello World" 25 | time.sleep(0.5) 26 | ``` 27 | 28 | then while your code is running, launch sysdig: 29 | 30 | ```sh 31 | $ sysdig evt.type=tracer 32 | 11132 12:58:56.203177473 0 python (11163) > tracer id=11163 tags=example/simple.py:5() args= 33 | 11136 12:58:56.203257412 0 python (11163) < tracer id=11163 tags=example/simple.py:5() args= 34 | 12570 12:58:56.705334633 2 python (11163) > tracer id=11163 tags=example/simple.py:5() args= 35 | 12615 12:58:56.705540522 2 python (11163) < tracer id=11163 tags=example/simple.py:5() args= 36 | 14202 12:58:57.207921927 2 python (11163) > tracer id=11163 tags=example/simple.py:5() args= 37 | 14245 12:58:57.208221298 2 python (11163) < tracer id=11163 tags=example/simple.py:5() args= 38 | 15672 12:58:57.710556623 3 python (11163) > tracer id=11163 tags=example/simple.py:5() args= 39 | 15680 12:58:57.710613724 3 python (11163) < tracer id=11163 tags=example/simple.py:5() args= 40 | 17325 12:58:58.213161095 3 python (11163) > tracer id=11163 tags=example/simple.py:5() args= 41 | 17333 12:58:58.213259041 3 python (11163) < tracer id=11163 tags=example/simple.py:5() args= 42 | ``` 43 | 44 | You can also use it as a decorator to automatically trace each function call: 45 | 46 | ```python 47 | from sysdig_tracers import Tracer 48 | import time 49 | 50 | @Tracer 51 | def myprinter(): 52 | print "Hello World" 53 | 54 | while True: 55 | myprinter() 56 | time.sleep(0.5) 57 | ``` 58 | 59 | And in sysdig you will see: 60 | 61 | ```sh 62 | $ sysdig evt.type=tracer 63 | 2542 13:01:25.798147410 1 python (11171) > tracer id=11171 tags=myprinter args= 64 | 2546 13:01:25.798198636 1 python (11171) < tracer id=11171 tags=myprinter args= 65 | 4176 13:01:26.298901248 1 python (11171) > tracer id=11171 tags=myprinter args= 66 | 4180 13:01:26.298988231 1 python (11171) < tracer id=11171 tags=myprinter args= 67 | 5550 13:01:26.799701837 1 python (11171) > tracer id=11171 tags=myprinter args= 68 | 5554 13:01:26.799757884 1 python (11171) < tracer id=11171 tags=myprinter args= 69 | 7150 13:01:27.300566452 1 python (11171) > tracer id=11171 tags=myprinter args= 70 | 7154 13:01:27.300669953 1 python (11171) < tracer id=11171 tags=myprinter args= 71 | 8502 13:01:27.801823005 1 python (11171) > tracer id=11171 tags=myprinter args= 72 | ``` 73 | 74 | For more advanced usages see the [examples](https://github.com/draios/tracers-py/tree/master/examples) directory or our [tests](https://github.com/draios/tracers-py/blob/master/test.py) 75 | -------------------------------------------------------------------------------- /test.py: -------------------------------------------------------------------------------- 1 | from sysdig_tracers import Tracer, Args, ReturnValue, Kwds 2 | import sysdig_tracers 3 | import os 4 | import fcntl 5 | import sys 6 | import pytest 7 | import re 8 | 9 | # hack to send tracers to a pipe and allow unit testing 10 | read_end, write_end = os.pipe() 11 | sysdig_tracers.NULL_FD = write_end 12 | fcntl.fcntl(read_end, fcntl.F_SETFL, os.O_NONBLOCK) 13 | 14 | def check_pipe_content(s): 15 | content = "" 16 | try: 17 | content = os.read(read_end, 1024) 18 | if sys.version_info[0] == 3: 19 | content = str(content, 'ascii') 20 | except: 21 | pass 22 | exp = re.compile(s) 23 | assert exp.match(content) 24 | 25 | def test_with(): 26 | with Tracer("myname"): 27 | x = 5 28 | y = 6 29 | check_pipe_content(">:t:myname::<:t:myname::") 30 | 31 | def test_with_and_args(): 32 | with Tracer("myname", {"x": "8"}): 33 | x = 5 34 | y = 6 35 | check_pipe_content(">:t:myname:x=8:<:t:myname::") 36 | 37 | def test_auto_naming(): 38 | with Tracer(): 39 | x = 5 40 | y = 6 41 | check_pipe_content(r">:t:[^:]*test\\\.py\\:[0-9]+\(test_auto_naming\)::<:t:[^:]*test\\\.py\\:[0-9]+\(test_auto_naming\)::") 42 | 43 | def test_decorator(): 44 | @Tracer 45 | def myfunction(): 46 | x = 5 47 | y = 6 48 | myfunction() 49 | check_pipe_content(">:t:myfunction::<:t:myfunction::") 50 | 51 | def test_start_stop(): 52 | t = Tracer() 53 | t.start() 54 | x = 8 55 | y = 5 56 | t.stop(args={"x": x}) 57 | check_pipe_content(r">:t:[^:]*test\\\.py\\:[0-9]+\(test_start_stop\)::<:t:[^:]*test\\\.py\\:[0-9]+\(test_start_stop\):x=8:") 58 | 59 | t.start("mytest") 60 | y = 6 61 | x = 7 62 | t.stop(args={"x": x}) 63 | check_pipe_content(">:t:mytest::<:t:mytest:x=7:") 64 | 65 | def test_auto_naming_in_nested_scope(): 66 | def f(): 67 | with Tracer(): 68 | x = 5 69 | y = 6 70 | def g(): 71 | f() 72 | g() 73 | check_pipe_content(r">:t:[^:]*test\\\.py\\:[0-9]+\(f\)::<:t:[^:]*test\\\.py\\:[0-9]+\(f\)::") 74 | 75 | def test_nested_tracer(): 76 | with Tracer("g") as g: 77 | x = 8 78 | with g.span("f"): 79 | y = 8 80 | with g.span("h") as h: 81 | p = 19 82 | with h.span("u"): 83 | u = 80 84 | check_pipe_content(">:t:g::>:t:g.f::<:t:g.f::>:t:g.h::>:t:g.h.u::<:t:g.h.u::<:t:g.h::<:t:g::") 85 | 86 | def test_nested_tracer_autonaming(): 87 | with Tracer() as g: 88 | x = 8 89 | with g.span(): 90 | y = 8 91 | with g.span() as h: 92 | p = 19 93 | with h.span(): 94 | u = 80 95 | 96 | func = r"[^:]*test\\\.py\\:[0-9]+\(test_nested_tracer_autonaming\)" 97 | check_pipe_content(r">:t:" + func + "::>:t:" + func + r"\." + func + "::<:t:" 98 | + func + r"\." + func + "::>:t:" + func + r"\." + func + "::>:t:" + func 99 | + r"\." + func + r"\." + func + "::<:t:" + func + r"\." + func + r"\." + 100 | func + "::<:t:" + func + r"\." + func + "::<:t:" + func + "::") 101 | 102 | def test_decorator_complex(): 103 | @Tracer 104 | def myfunction(x, y): 105 | return x*y 106 | assert myfunction(3, 4) == 12 107 | check_pipe_content(">:t:myfunction::<:t:myfunction::") 108 | 109 | def test_decorator_complex_args(): 110 | @Tracer(enter_args={"iterative": 1}) 111 | def myfunction(x, y): 112 | return x*y 113 | assert myfunction(3, 4) == 12 114 | check_pipe_content(">:t:myfunction::<:t:myfunction::") 115 | 116 | def test_exit_args(): 117 | @Tracer(enter_args={"n": Args(0)}, exit_args={"ret": ReturnValue}) 118 | def factorial(n): 119 | ret = 1 120 | while n > 0: 121 | ret *= n 122 | n -= 1 123 | return ret 124 | assert factorial(9) == 9*8*7*6*5*4*3*2*1 125 | check_pipe_content(">:t:factorial:n=9:<:t:factorial:ret=362880:") 126 | 127 | def test_exit_kwds(): 128 | @Tracer(enter_args={"n": Kwds("n")}, exit_args={"ret": ReturnValue}) 129 | def factorial(n): 130 | ret = 1 131 | while n > 0: 132 | ret *= n 133 | n -= 1 134 | return ret 135 | assert factorial(n=9) == 9*8*7*6*5*4*3*2*1 136 | check_pipe_content(">:t:factorial:n=9:<:t:factorial:ret=362880:") 137 | 138 | def test_decorator_as_method(): 139 | class MyTestClass(object): 140 | def __init__(self): 141 | self.x = 90 142 | 143 | @Tracer 144 | def doWork(self): 145 | y = self.x + 80 146 | 147 | inst = MyTestClass() 148 | inst.doWork() 149 | check_pipe_content(">:t:doWork::<:t:doWork::") 150 | 151 | def test_recursive_functions(): 152 | @Tracer(enter_args={"n": Args(0)}, exit_args={"ret": ReturnValue}) 153 | def factorial(n): 154 | if n == 1: 155 | return 1 156 | else: 157 | return n * factorial(n-1) 158 | assert factorial(9) == 9*8*7*6*5*4*3*2*1 159 | check_pipe_content(">:t:factorial:n=9:<:t:factorial:ret=362880:") 160 | -------------------------------------------------------------------------------- /sysdig_tracers.py: -------------------------------------------------------------------------------- 1 | # Copyright (C) 2016 Sysdig inc. 2 | # All rights reserved 3 | 4 | # Author: Luca Marturana (luca@sysdig.com) 5 | 6 | import os 7 | import traceback 8 | from inspect import isfunction 9 | import sys 10 | import functools 11 | 12 | # ensure file descriptor will be closed on execve 13 | O_CLOEXEC = 524288 # cannot use octal because they have different syntax on python2 and 3 14 | NULL_FD = os.open("/dev/null", os.O_WRONLY | os.O_NONBLOCK | O_CLOEXEC) 15 | 16 | class Args(object): 17 | """ 18 | Use this class to tell Tracer to extract positional function arguments 19 | and emit them to the trace: 20 | 21 | @Tracer(enter_args={"n": Args(0)}) 22 | def myfunction(n): 23 | pass 24 | 25 | myfunction(9) 26 | """ 27 | def __init__(self, i): 28 | self.i = i 29 | 30 | def __call__(self, args): 31 | return args[self.i] 32 | 33 | class Kwds(object): 34 | """ 35 | Use this class to tell Tracer to extract keyword function arguments 36 | and emit them to the trace: 37 | 38 | @Tracer(enter_args={"n": Kwds("n")}) 39 | def myfunction(n): 40 | pass 41 | 42 | myfunction(n=9) 43 | """ 44 | def __init__(self, key): 45 | self.key = key 46 | 47 | def __call__(self, kwds): 48 | return kwds[self.key] 49 | 50 | class ReturnValue(object): 51 | """ 52 | Use this class to tell Tracer to extract return value of a function 53 | and emit them to the trace: 54 | 55 | @Tracer(exit_args={"n": ReturnValue}) 56 | def myfunction(): 57 | return 8 58 | 59 | myfunction() 60 | """ 61 | pass 62 | 63 | class Tracer(object): 64 | """ 65 | This class allows you to add a tracer to a function, a method or 66 | to instrument specific part of code. Use it as decorator: 67 | 68 | @Tracer 69 | def myfuction(): 70 | pass 71 | 72 | or using `with` syntax: 73 | 74 | with Tracer(): 75 | pass 76 | 77 | """ 78 | 79 | def __init__(self, tag=None, enter_args=None, exit_args=None): 80 | """ 81 | Create a new Tracer, all arguments are optional: 82 | 83 | tag -- tag name, by default is auto-detected by the code line or function name 84 | enter_args -- dictionary of enter arguments for the trace, use Args, Kwds to extract function arguments 85 | exit_args -- dictionary of exit arguments for the trace, use ReturnValue to extract function return value 86 | """ 87 | self.__detect_tag(tag) 88 | self.enter_args = enter_args if not enter_args is None else {} 89 | self.exit_args = exit_args if not exit_args is None else {} 90 | 91 | def __detect_tag(self, tag): 92 | if isinstance(tag, str): 93 | self.tag = tag 94 | elif isfunction(tag): 95 | self.tag = tag.__name__ 96 | self.wrapped_func = tag 97 | self.function_calls = 0 98 | else: 99 | tb = traceback.extract_stack(None, 3)[0] 100 | filepath = tb[0] 101 | filepath = filepath[filepath.rfind("/",0, filepath.rfind("/"))+1:] 102 | filepath = filepath.replace(".", "\.") 103 | self.tag = "%s\:%d(%s)" % (filepath, tb[1], tb[2].replace("<","\<").replace(">","\>")) 104 | 105 | def __emit_trace(self, direction, args=None): 106 | if args is None: 107 | args = {} 108 | args_s = ",".join(["%s=%s" % item for item in args.items()]) 109 | tracer = "%s:t:%s:%s:" % (direction, self.tag, args_s) 110 | if sys.version_info[0] == 3: 111 | tracer = bytes(tracer, 'ascii') 112 | try: 113 | os.write(NULL_FD, tracer) 114 | except OSError: 115 | pass 116 | 117 | def __enter__(self): 118 | self.__emit_trace(">", self.enter_args) 119 | return self 120 | 121 | def __exit__(self, exc_type, exc_value, exc_traceback): 122 | self.__emit_trace("<") 123 | 124 | def __call__(self, *args, **kwds): 125 | if len(args) == 1 and callable(args[0]): 126 | # This happens when Tracer is used as: 127 | # 128 | # @Tracer(enter_args= ..) 129 | # def myf(): .... 130 | self.__detect_tag(args[0]) 131 | return self 132 | else: 133 | # This happens when Tracer is used as: 134 | # 135 | # @Tracer 136 | # def myf(): .... 137 | 138 | if self.function_calls == 0: 139 | enter_args = {} 140 | for key, value in self.enter_args.items(): 141 | if isinstance(value, Args): 142 | enter_args[key] = value(args) 143 | elif isinstance(value, Kwds): 144 | enter_args[key] = value(kwds) 145 | elif isinstance(value, str): 146 | enter_args[key] = value 147 | self.__emit_trace(">", enter_args) 148 | 149 | # function_calls counter helps to detect recursive calls 150 | # and print them only once 151 | self.function_calls += 1 152 | res = self.wrapped_func(*args, **kwds) 153 | self.function_calls -= 1 154 | 155 | if self.function_calls == 0: 156 | exit_args = {} 157 | for key, value in self.exit_args.items(): 158 | if value == ReturnValue: 159 | exit_args[key] = res 160 | elif isinstance(value, str): 161 | exit_args[key] = value 162 | self.__emit_trace("<", exit_args) 163 | return res 164 | 165 | def start(self, tag=None, args=None): 166 | """ 167 | Emit a tracer enter event. 168 | 169 | This method allows to fine control trace emission 170 | 171 | t = Tracer() 172 | t.start() 173 | [code] 174 | t.stop() 175 | 176 | is equal to: 177 | 178 | with Tracer(): 179 | [code] 180 | 181 | tag -- same as __init__ 182 | args -- dictionary of enter args 183 | """ 184 | self.__detect_tag(tag) 185 | self.__emit_trace(">", args) 186 | 187 | def stop(self, args=None): 188 | """ 189 | Emit an exit trace event 190 | 191 | See start() for further details 192 | """ 193 | self.__emit_trace("<", args) 194 | 195 | def span(self, tag=None, enter_args=None, exit_args=None): 196 | """ 197 | Create a nested span inside a tracer, 198 | the usage is the same of Tracer() itself: 199 | 200 | with Tracer() as t: 201 | [code] 202 | with t.span() as child: 203 | [othercode] 204 | 205 | """ 206 | t = Tracer("", enter_args, exit_args) 207 | t.__detect_tag(tag) 208 | t.tag = "%s.%s" % (self.tag, t.tag) 209 | return t 210 | 211 | def __get__(self, obj, objtype): 212 | # This is needed to support decorating methods 213 | # instead of spare functions 214 | return functools.partial(self.__call__, obj) 215 | -------------------------------------------------------------------------------- /LICENSE.txt: -------------------------------------------------------------------------------- 1 | GNU GENERAL PUBLIC LICENSE 2 | Version 2, June 1991 3 | 4 | Copyright (C) 1989, 1991 Free Software Foundation, Inc., 5 | 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 6 | Everyone is permitted to copy and distribute verbatim copies 7 | of this license document, but changing it is not allowed. 8 | 9 | Preamble 10 | 11 | The licenses for most software are designed to take away your 12 | freedom to share and change it. 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However, as a 160 | special exception, the source code distributed need not include 161 | anything that is normally distributed (in either source or binary 162 | form) with the major components (compiler, kernel, and so on) of the 163 | operating system on which the executable runs, unless that component 164 | itself accompanies the executable. 165 | 166 | If distribution of executable or object code is made by offering 167 | access to copy from a designated place, then offering equivalent 168 | access to copy the source code from the same place counts as 169 | distribution of the source code, even though third parties are not 170 | compelled to copy the source along with the object code. 171 | 172 | 4. You may not copy, modify, sublicense, or distribute the Program 173 | except as expressly provided under this License. Any attempt 174 | otherwise to copy, modify, sublicense or distribute the Program is 175 | void, and will automatically terminate your rights under this License. 176 | However, parties who have received copies, or rights, from you under 177 | this License will not have their licenses terminated so long as such 178 | parties remain in full compliance. 179 | 180 | 5. You are not required to accept this License, since you have not 181 | signed it. However, nothing else grants you permission to modify or 182 | distribute the Program or its derivative works. These actions are 183 | prohibited by law if you do not accept this License. Therefore, by 184 | modifying or distributing the Program (or any work based on the 185 | Program), you indicate your acceptance of this License to do so, and 186 | all its terms and conditions for copying, distributing or modifying 187 | the Program or works based on it. 188 | 189 | 6. Each time you redistribute the Program (or any work based on the 190 | Program), the recipient automatically receives a license from the 191 | original licensor to copy, distribute or modify the Program subject to 192 | these terms and conditions. You may not impose any further 193 | restrictions on the recipients' exercise of the rights granted herein. 194 | You are not responsible for enforcing compliance by third parties to 195 | this License. 196 | 197 | 7. If, as a consequence of a court judgment or allegation of patent 198 | infringement or for any other reason (not limited to patent issues), 199 | conditions are imposed on you (whether by court order, agreement or 200 | otherwise) that contradict the conditions of this License, they do not 201 | excuse you from the conditions of this License. If you cannot 202 | distribute so as to satisfy simultaneously your obligations under this 203 | License and any other pertinent obligations, then as a consequence you 204 | may not distribute the Program at all. For example, if a patent 205 | license would not permit royalty-free redistribution of the Program by 206 | all those who receive copies directly or indirectly through you, then 207 | the only way you could satisfy both it and this License would be to 208 | refrain entirely from distribution of the Program. 209 | 210 | If any portion of this section is held invalid or unenforceable under 211 | any particular circumstance, the balance of the section is intended to 212 | apply and the section as a whole is intended to apply in other 213 | circumstances. 214 | 215 | It is not the purpose of this section to induce you to infringe any 216 | patents or other property right claims or to contest validity of any 217 | such claims; this section has the sole purpose of protecting the 218 | integrity of the free software distribution system, which is 219 | implemented by public license practices. Many people have made 220 | generous contributions to the wide range of software distributed 221 | through that system in reliance on consistent application of that 222 | system; it is up to the author/donor to decide if he or she is willing 223 | to distribute software through any other system and a licensee cannot 224 | impose that choice. 225 | 226 | This section is intended to make thoroughly clear what is believed to 227 | be a consequence of the rest of this License. 228 | 229 | 8. If the distribution and/or use of the Program is restricted in 230 | certain countries either by patents or by copyrighted interfaces, the 231 | original copyright holder who places the Program under this License 232 | may add an explicit geographical distribution limitation excluding 233 | those countries, so that distribution is permitted only in or among 234 | countries not thus excluded. In such case, this License incorporates 235 | the limitation as if written in the body of this License. 236 | 237 | 9. The Free Software Foundation may publish revised and/or new versions 238 | of the General Public License from time to time. Such new versions will 239 | be similar in spirit to the present version, but may differ in detail to 240 | address new problems or concerns. 241 | 242 | Each version is given a distinguishing version number. If the Program 243 | specifies a version number of this License which applies to it and "any 244 | later version", you have the option of following the terms and conditions 245 | either of that version or of any later version published by the Free 246 | Software Foundation. If the Program does not specify a version number of 247 | this License, you may choose any version ever published by the Free Software 248 | Foundation. 249 | 250 | 10. If you wish to incorporate parts of the Program into other free 251 | programs whose distribution conditions are different, write to the author 252 | to ask for permission. For software which is copyrighted by the Free 253 | Software Foundation, write to the Free Software Foundation; we sometimes 254 | make exceptions for this. Our decision will be guided by the two goals 255 | of preserving the free status of all derivatives of our free software and 256 | of promoting the sharing and reuse of software generally. 257 | 258 | NO WARRANTY 259 | 260 | 11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY 261 | FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN 262 | OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES 263 | PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED 264 | OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 265 | MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS 266 | TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE 267 | PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, 268 | REPAIR OR CORRECTION. 269 | 270 | 12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING 271 | WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR 272 | REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, 273 | INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING 274 | OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED 275 | TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY 276 | YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER 277 | PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE 278 | POSSIBILITY OF SUCH DAMAGES. 279 | 280 | END OF TERMS AND CONDITIONS 281 | 282 | How to Apply These Terms to Your New Programs 283 | 284 | If you develop a new program, and you want it to be of the greatest 285 | possible use to the public, the best way to achieve this is to make it 286 | free software which everyone can redistribute and change under these terms. 287 | 288 | To do so, attach the following notices to the program. It is safest 289 | to attach them to the start of each source file to most effectively 290 | convey the exclusion of warranty; and each file should have at least 291 | the "copyright" line and a pointer to where the full notice is found. 292 | 293 | {description} 294 | Copyright (C) {year} {fullname} 295 | 296 | This program is free software; you can redistribute it and/or modify 297 | it under the terms of the GNU General Public License as published by 298 | the Free Software Foundation; either version 2 of the License, or 299 | (at your option) any later version. 300 | 301 | This program is distributed in the hope that it will be useful, 302 | but WITHOUT ANY WARRANTY; without even the implied warranty of 303 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 304 | GNU General Public License for more details. 305 | 306 | You should have received a copy of the GNU General Public License along 307 | with this program; if not, write to the Free Software Foundation, Inc., 308 | 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. 309 | 310 | Also add information on how to contact you by electronic and paper mail. 311 | 312 | If the program is interactive, make it output a short notice like this 313 | when it starts in an interactive mode: 314 | 315 | Gnomovision version 69, Copyright (C) year name of author 316 | Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'. 317 | This is free software, and you are welcome to redistribute it 318 | under certain conditions; type `show c' for details. 319 | 320 | The hypothetical commands `show w' and `show c' should show the appropriate 321 | parts of the General Public License. Of course, the commands you use may 322 | be called something other than `show w' and `show c'; they could even be 323 | mouse-clicks or menu items--whatever suits your program. 324 | 325 | You should also get your employer (if you work as a programmer) or your 326 | school, if any, to sign a "copyright disclaimer" for the program, if 327 | necessary. Here is a sample; alter the names: 328 | 329 | Yoyodyne, Inc., hereby disclaims all copyright interest in the program 330 | `Gnomovision' (which makes passes at compilers) written by James Hacker. 331 | 332 | {signature of Ty Coon}, 1 April 1989 333 | Ty Coon, President of Vice 334 | 335 | This General Public License does not permit incorporating your program into 336 | proprietary programs. If your program is a subroutine library, you may 337 | consider it more useful to permit linking proprietary applications with the 338 | library. If this is what you want to do, use the GNU Lesser General 339 | Public License instead of this License. 340 | --------------------------------------------------------------------------------