What is the difference between HTTP_PROXY and https_proxy?

How to set HTTP_PROXY environment variable in Linux permanently?

I have set up a proxy server to forward my browser traffic through it, but when I close that browser window, the HTTPPROXY environment variable is not retained and I have to set it every time I launch a new browser window.

I'm running Ubuntu 12.04 and have tried everything, even set it as a startup script.

How do I set this permanently? When you close the window, you're not doing it from a terminal. As a result, the shell won't retain the environment variable. That's the problem, and there's nothing you can do about it.

What is the difference between HTTP_PROXY and All_proxy?

I'm using a proxy which supports ssl.

I want to use only a socks5 proxy, but I can't find the difference between HTTPPROXY and Allproxy.

HTTPPROXY allows you to specify any proxy address.0.1:8080

However, if we had an environment variable called HTTPPROXY, it would only accept a URL, which is not allowed to specify a specific address. The short answer is that HTTPPROXY is just a synonym for ALLPROXY, which is defined in the Proxy Auto Discovery protocol. In other words, "Allproxy" isn't actually defined anywhere.

There's no technical reason why you wouldn't be able to use httpproxy as a stand-in for all proxies, or any proxy that supports TCP proxying, but there's nothing you can really count on with HTTPPROXY. It can break on some hosts. It can ignore settings passed in from the command line. It will always honor some setting in the systemwide configuration. In the past, it hasn't honored proxy port numbers.

What is the difference between HTTP_PROXY and https_proxy?

On many linux distros, httpproxy and httpsproxy are linked together.

Both points to the same place: /etc/environment, but it seems to have been the way in the past, but not nowadays.

Httpproxy is a environment variable which does some tricks to make sure that only specific sites are visible to clients. For instance, to be able to have more than one proxy server on the same server, httpproxy needs to be set to the name of a file containing all of those proxies, and this file has to be called /etc/httpproxy. This file needs to contain entries with a format such as this:

:port. Where site is the domain and port is the proxy server port. (httpsproxy can be used without httpproxy).

Httpproxy requires sudo, while httpsproxy does not. When both httpproxy and httpsproxy exist, what should I use? I have just encountered this problem on a RedHat 5.8 box. The following worked for me:
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