小编Dan*_*lez的帖子

我有这个makefile：

echo:
    echo "PASS=$(PASS)"

我调用：

PASS='MYPA$$' make

这显示了我：

echo "PASS=MYPA$"
PASS=MYPA$

有人在评估$$->$。

这是壳吗？不是在输入值时，因为我使用单引号，防止外壳对其进行评估。

也许 make 调用的 shell 正在执行此操作...

或者是不是 make本身？

我怎样才能避免它？

docker-compose exec从读取时失败stdin：

$ echo "use mydb; show measurements;" | docker-compose exec influxdb influx
Connected to http://localhost:8086 version 1.2.4
InfluxDB shell version: 1.2.4
> Traceback (most recent call last):
  File "/usr/local/bin/docker-compose", line 9, in <module>
    load_entry_point('docker-compose==1.9.0', 'console_scripts', 'docker-compose')()
  File "/usr/local/lib/python2.7/dist-packages/compose/cli/main.py", line 65, in main
    command()
  File "/usr/local/lib/python2.7/dist-packages/compose/cli/main.py", line 117, in perform_command
    handler(command, command_options)
  File "/usr/local/lib/python2.7/dist-packages/compose/cli/main.py", line 462, in exec_command
    pty.start()
  File "/usr/local/lib/python2.7/dist-packages/dockerpty/pty.py", line 338, in start
    io.set_blocking(pump, flag)
  File "/usr/local/lib/python2.7/dist-packages/dockerpty/io.py", line 32, in set_blocking
    old_flag = fcntl.fcntl(fd, fcntl.F_GETFL) …

似乎保留字不能在python中用作属性：

$ python
Python 3.6.2 |Continuum Analytics, Inc.| (default, Jul 20 2017, 13:51:32) 
[GCC 4.4.7 20120313 (Red Hat 4.4.7-1)] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> class A:
>>>     global = 3
  File "<stdin>", line 2
    global = 3
           ^
SyntaxError: invalid syntax

这似乎是明智的，因为它是模棱两可的：我在global这里使用关键字吗？很难说。

但这不是明智的恕我直言：

>>> class A: pass
>>> a = A()
>>> a.global = 3
  File "<stdin>", line 1
    a.global = 3
           ^
SyntaxError: invalid syntax
>>> a.def = 4
  File …