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

Hongyi Zhao via curl-users <[email protected]> Sat, 9 Dec 2023 09:37:18 +0800

Newsgroups	gmane.comp.web.curl.general
Message-ID	<CAGP6POLcrg8Cayi=OAKsfNtL6NDZaER1bFf77+WWDx_BqZFvCg@mail.gmail.com>

On Fri, Dec 8, 2023 at 10:44 AM Dan Fandrich via curl-users
<[email protected]> 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@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.

Regards,
Zhao

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callback-SIGINT.py (text/x-python, 2.6 KB)

import subprocess
import time
import pycurl
import signal
from io import BytesIO
import sys


def fetch_proxies():
    command = 'echo "show stat" | sudo socat stdio /var/run/haproxy.sock 2>/dev/null | awk -F, \'$1=="socks5" && !($2~/^(FRONTEND|BACKEND)$/) {print $2,$74}\''
    process = subprocess.Popen(command, stdout=subprocess.PIPE, shell=True)
    output, error = process.communicate()

    result_dict = {}

    if error is not None:
        return result_dict

    lines = output.decode('utf-8').split('\n')

    for line in lines:
        if line != "":
            key_value = line.split(' ')
            result_dict[key_value[0]] = key_value[1]

    return result_dict


def test_proxy(proxy, url):
    global last_calc_time, download_start_time, kb_interrupt

    kb_interrupt = False

    buffer = BytesIO()

    c = pycurl.Curl()
    c.setopt(pycurl.URL, url)
    c.setopt(pycurl.WRITEDATA, buffer)
    c.setopt(pycurl.PROXY, proxy)
    c.setopt(pycurl.PROXYTYPE, pycurl.PROXYTYPE_SOCKS5_HOSTNAME)
    c.setopt(pycurl.NOPROGRESS, False)
    c.setopt(pycurl.XFERINFOFUNCTION, progress)
    c.setopt(pycurl.TIMEOUT, 5)

    download_start_time = time.time()
    last_calc_time = download_start_time

    signal.pthread_sigmask(signal.SIG_BLOCK, [signal.SIGINT])

    try:
        c.perform()
    except pycurl.error as e:
        pass

    signal.pthread_sigmask(signal.SIG_UNBLOCK, [signal.SIGINT])

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


def progress(download_t, download_d, upload_t, upload_d):
    global last_calc_time, download_start_time, kb_interrupt
    current_time = time.time()

    if current_time - last_calc_time >= 2:
        elapsed_time = current_time - download_start_time
        current_speed = download_d / elapsed_time / 1024
        print(f"Current Speed: {current_speed:.2f} kB/s")
        last_calc_time = current_time

    try:
        signal.pthread_sigmask(signal.SIG_UNBLOCK, [signal.SIGINT])
    except KeyboardInterrupt:
        kb_interrupt = True
        print('interrupted!')
        return 1
    finally:
        signal.pthread_sigmask(signal.SIG_BLOCK, [signal.SIGINT])

proxy_data = fetch_proxies()
url = "http://ipv4.download.thinkbroadband.com/1GB.zip"

kb_interrupt = False

for key, value in proxy_data.items():
    print(f"Proxy: {key}")

    if kb_interrupt:
        print("Script terminated by user. Exiting.")
        sys.exit(0)

    try:
        average_speed = test_proxy(value, url)
        print(f"Average Speed: {average_speed:.2f} kB/s")
    except KeyboardInterrupt:
        print("Keyboard interrupt encountered during proxy testing. Exiting.")
        break