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Someone's set up a proxy on my machine and I want to know what it is. Is there a way to find the proxy server using the command line and not the GUI?

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  • Does echo $HTTP_PROXY do anything? Sep 29, 2016 at 17:14
  • I notice you had mentioned you were using 15.04 in your original post. Please consider upgrading to 16.04 because 15.04 has gone EOL.
    – edwinksl
    Sep 29, 2016 at 17:18
  • Does the command gsettings get org.gnome.system.proxy host return anything?
    – Terrance
    Sep 29, 2016 at 17:32
  • seems to be a duplicate of: serverfault.com/questions/278189/… Mar 4, 2022 at 7:58

5 Answers 5

20

For any system-wide proxy for HTTP, you can check the value of http_proxy environment variable:

echo "$http_proxy"

For HTTPS:

echo "$https_proxy"

Similarly, there are ftp_proxy, socks_proxy for serving the exact purpose of their names. There is also all_proxy for setting proxy for all these protocols at once. Just to note, no_proxy unsets proxy for any specific addresses of any (or all) given protocol. Just for sake of completeness, you might want to check the uppercase version of these variables too, although the lowercases are standard for *_proxy environment variables (only environment variables i am aware of that are lowercased).

Note that, these will show any system-wide proxy setting, not application-specific. For example, firefox, or apt can have their own proxy settings irrespective of any global one. Some applications do not honor these variables too (e.g. specific gnome apps use gsettings), so YMMV.

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  • 1
    After I run 'echo "$http_proxy" ' it shows yust one blank row, is that mean that I don't have proxy on my server? Sep 29, 2016 at 17:22
  • @SkulaSadam Check my edits.
    – heemayl
    Sep 29, 2016 at 17:24
12

Attempt an http connection to the outside:

wget http://google.com

You'll see something like this as a result:

--2017-06-12 13:02:53--  http://google.com/
Resolving google.com (google.com)... 172.217.11.142, 2607:f8b0:4002:810::200e
Connecting to google.com (google.com)|172.217.11.142|:80... connected.
HTTP request sent, awaiting response... 302 authenticationrequired
Location: http://192.168.254.99:9090/mwg-internal/de5fs23hu73ds/plugin?target=Auth&reason=Auth&ClientID=3130909038&ttl=600&url=aHR0cDovL2dvb2dsZS5jb20v&rnd=1497286973 [following]
--2017-06-12 13:02:53--  http://192.168.254.99:9090/mwg-internal/de5fs23hu73ds/plugin?target=Auth&reason=Auth&ClientID=3130909038&ttl=600&url=aHR0cDovL2dvb2dsZS5jb20v&rnd=1497286973
Connecting to 192.168.254.99:9090... connected.
HTTP request sent, awaiting response... 401 authenticationrequired

Your proxy server in this case is found after the 302 authentication required. http://192.168.254.99:9090/

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In Linux, you can use this to check the proxies defined in the system

env | grep proxy
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  • 2
    env | grep -i proxy
    – nixmind
    Mar 8, 2020 at 0:36
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check the file :

cat /etc/apt/apt.conf
cat /etc/environment

To Modify contents of file (remove everything from apt.conf for no proxy and only proxy sentences from environment)!

sudo nano /etc/apt/apt.conf
sudo nano /etc/environment
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  • gedit is a GUI program. How does this avoid using the GUI? Sep 29, 2016 at 17:38
  • use cat then @Zacharee1.. i said gedit so OP can also edit it.
    – minigeek
    Sep 29, 2016 at 17:40
  • gedit might not even be installed, as this could be a server installation. nano and vim are both command line text editors. Sep 29, 2016 at 17:41
  • @Zacharee1 hmm ..they r universal.I will edit solution thanx
    – minigeek
    Sep 29, 2016 at 17:42
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    Removing everything in /etc/environment will break PATH and possibly other configurations. Please don't do that. Sep 29, 2016 at 17:46
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# netstat -na

OR, if you think/guess any proxy server then grep it to confirm, e.g.

# netstat -na |grep <ProxyGuess IP>
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  • these your answer does not tell what to look for exactly in the first half. and it does not answer the central part of the question of "i want to know what it is" because you are assuming something central must already know in order to get the answer. Mar 4, 2022 at 7:46

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