cURL

$ curl https://bootstrap.pypa.io/get-pip.py -o get-pip.py
curl: (7) couldn't connect to host

-xを使う

 -x/--proxy <host[:port]> Use HTTP proxy on given port
    --proxy-anyauth Pick "any" proxy authentication method (H)
    --proxy-basic   Use Basic authentication on the proxy (H)
    --proxy-digest  Use Digest authentication on the proxy (H)
    --proxy-negotiate Use Negotiate authentication on the proxy (H)
    --proxy-ntlm    Use NTLM authentication on the proxy (H)

$ curl -x http://192.***.***.***:****/ https://bootstrap.pypa.io/get-pip.py -o get-
pip.py
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100 1488k  100 1488k    0     0  3381k      0 --:--:-- --:--:-- --:--:-- 5816k

Wget

$ wget --no-check-certificate https://access.redhat.com
--2016-07-15 19:13:54--  https://access.redhat.com/
access.redhat.com をDNSに問いあわせています... ***.***.***.***
access.redhat.com|***.***.***.***|:443 に接続しています... 失敗しました: 接続がタイムアウトしました.

/etc/wgetrcに明示的に有効と記述する

--- /etc/wgetrc.orig    2016-07-15 19:11:40.368050104 +0900
+++ /etc/wgetrc 2016-07-15 19:16:53.756649933 +0900
@@ -77,9 +77,11 @@
 # They will override the value in the environment.
 #https_proxy = http://proxy.yoyodyne.com:18023/
 #http_proxy = http://proxy.yoyodyne.com:18023/
+http_proxy = http://192.***.***.***:****/
+https_proxy = http://192.***.***.***:****/
 #ftp_proxy = http://proxy.yoyodyne.com:18023/
 # If you do not want to use proxy at all, set this to off.
-#use_proxy = on
+use_proxy = on
 
 # You can customize the retrieval outlook.  Valid options are default,
 # binary, mega and micro.

$ wget --no-check-certificate https://access.redhat.com
--2016-07-15 19:19:14--  https://access.redhat.com/
192.***.***.***:****/ に接続しています... 接続しました。
Proxy による接続要求を送信しました、応答を待っています... 200 OK
長さ: 89324 (87K) [text/html]
`index.html' に保存中

100%[===============================================================>] 89,324      --.-K/s 時間 0.07s   

2016-07-15 19:19:15 (1.29 MB/s) - `index.html' へ保存完了 [89324/89324]

環境変数

登録

$ export http_proxy=http://192.***.***.***:****/
$ export https_proxy=http://192.***.***.***:****/

削除

$ unset http_proxy
$ unset https_proxy