Re: Making Python Script Exit Completely with One Ctrl+C

From: Ray Satiro via curl-users <curl-users_at_lists.haxx.se>
Date: Fri, 8 Dec 2023 22:40:06 -0500

On 12/8/2023 8:49 PM, Hongyi Zhao via curl-users wrote:
> On Sat, Dec 9, 2023 at 9:37 AM Hongyi Zhao<hongyi.zhao_at_gmail.com> wrote:
>> On Fri, Dec 8, 2023 at 10:44 AM Dan Fandrich via curl-users
>> <curl-users_at_lists.haxx.se> wrote:
>>> On Fri, Dec 08, 2023 at 09:56:44AM +0800, Hongyi Zhao via curl-users wrote:
>>>> I tried the following method but in vain:
>>> [...]
>>>> try:
>>>> pass
>>>> except KeyboardInterrupt:
>>>> kb_interrupt = True
>>> This won't accomplish anything because "pass" will never raise an exception.
>>> I have a feeling that even putting the entire contents of the progress callback
>>> into a try/except block won't even help; I suspect the exception is raised the
>>> moment the Python interpreter is returned to by pycurl while calling that
>>> callback, which is before even that point.
>>>
>>> You'll probably have to block SIGINT before calling calling into pycurl, then
>>> unblocking in the progress callback to check it, e.g.
>>>
>>> ...
>>> signal.pthread_sigmask(signal.SIG_BLOCK, [signal.SIGINT])
>>> c.perform()
>>> signal.pthread_sigmask(signal.SIG_UNBLOCK, [signal.SIGINT])
>>> ...
>>>
>>> def progress(...):
>>> try:
>>> signal.pthread_sigmask(signal.SIG_UNBLOCK, [signal.SIGINT])
>>> except KeyboardInterrupt:
>>> print('interrupted!')
>>> return 1
>>> finally:
>>> signal.pthread_sigmask(signal.SIG_BLOCK, [signal.SIGINT])
>>>
>>> or just set your own SIGINT handler that sets a flag (kb_interrupt), then check
>>> that flag in the progress callback and return an error if it's set.
>> I tried using the first method of your tips. It works, but the
>> calculated*Average Speed* is too high, as shown below:
>>
>> (datasci) werner_at_X10DAi:~/Desktop$ python callback-SIGINT.py
>> Proxy: SG_ssr_futeapbquf5m.nodelist.club_1453_018d83c677e05e71f172014fc3f45e39
>> Current Speed: 1371.74 kB/s
>> Current Speed: 6565.90 kB/s
>> Average Speed: 7552.72 kB/s
>> Proxy: HK_ssr_wo8o8npg4fny.nodelist.club_1303_b5bf85111d0f51c517ec7302d3f33ce1
>> Current Speed: 1252.55 kB/s
>> Current Speed: 7461.93 kB/s
>> Average Speed: 8807.27 kB/s
>> Proxy: SG_ssr_futeapbquf5m.nodelist.club_1354_ddfba110eddfdb7037f389e9b5917477
>> Current Speed: 3081.76 kB/s
>> Current Speed: 9351.58 kB/s
>> Average Speed: 10745.23 kB/s
>> Proxy: HK_ssr_fwqvvo60u1mj.nodelist.club_1423_dba3b0996744e7b82eae7634626a5ba9
>> ^Cinterrupted!
>> Average Speed: 156.74 kB/s
>> Proxy: SG_ssr_futeapbquf5m.nodelist.club_1356_8ce27b1301fcbcb77cc5abb28cb127a6
>> Script terminated by user. Exiting.
>>
>> I'm not sure how to fix this problem. Attached please find the test script.
> I tried another method which also had the same problem:
>
> (datasci) werner_at_X10DAi:~/Desktop$ python rev-2.py
> Proxy: SG_ssr_futeapbquf5m.nodelist.club_1453_018d83c677e05e71f172014fc3f45e39
> Current Speed: 664.56 kB/s
> Current Speed: 7691.08 kB/s
> Average Speed: 9403.12 kB/s
> Proxy: HK_ssr_wo8o8npg4fny.nodelist.club_1303_b5bf85111d0f51c517ec7302d3f33ce1
> Current Speed: 950.39 kB/s
> Current Speed: 6146.08 kB/s
> Average Speed: 7297.46 kB/s
> Proxy: SG_ssr_futeapbquf5m.nodelist.club_1354_ddfba110eddfdb7037f389e9b5917477
> ^CTraceback (most recent call last):
> File "/home/werner/Desktop/rev-2.py", line 60, in progress
> def progress(download_t, download_d, upload_t, upload_d):
>
> KeyboardInterrupt


As far as I can tell you have some issues using Python and have been
receiving help in a Python discussion thread [1]. How does curl factor
into this except that the average speed looks wrong to you?

Your code does:

average_speed = c.getinfo(pycurl.SPEED_DOWNLOAD) / 1024

That should be ok. You are calculating the speed in KiB (though a lot of
people will abbreviate it as KB), and not kB (notice the lowercase 'k').
If you suspect that average speed pycurl is giving you is wrong then you
could compare against the curl tool.

For example  (based off your python code):

curl --max-time 5 --proxy
socks5h://SG_ssr_futeapbquf5m.nodelist.club_1453_018d83c677e05e71f172014fc3f45e39
-o /dev/null http://ipv4.download.thinkbroadband.com/1GB.zip

that would show progress information as the file is being downloaded (to
/dev/null) and the average speed.


[1]:
https://discuss.python.org/t/making-python-script-exit-completely-with-one-ctrl-c/40529/1

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Received on 2023-12-09