>npm config set proxy http://proxyhost:proxyport
>npm config set https-proxy http://proxyhost:proxyport

>npm config set proxy null
>npm config set https-proxy null

npm config set registry=http://registry.npmjs.org/
npm config set strict-ssl false

npm config set proxy false
npm cache clean

npm config rm proxy
npm config rm https-proxy

npm config set proxy http://proxyhostname:proxyport
npm config set https-proxy http://proxyhostname:proxyport

npm config set proxy http://USERNAME:passwd@proxyserver.co.uk:8080

env|grep -i proxy

http_proxy=http://192.168.X.X:8080/
ftp_proxy=ftp://192.168.X.X:8080/
socks_proxy=socks://192.168.X.X:8080/
https_proxy=https://192.168.X.X:8080/

unset(http_proxy)

rm ~/.npmrc

registry=https://registry.npmjs.org/
proxy=http://username:password@127.0.0.1:8888
https-proxy=http://username:password@127.0.0.1:8888
http-proxy=http://username:password@127.0.0.1:8888
strict-ssl=false
ca=null

env|grep -i proxy

HTTP-PROXY = "http://localhost:3128"
HTTPS-PROXY = "https://localhost:3128"
HTTPS_PROXY = "http://localhost:3128"
HTTP_PROXY = "http://localhost:3128"
PROXY = "http://localhost:3128"
http-proxy = "http://localhost:3128"
http_proxy = "http://localhost:3128"
https-proxy = "https://localhost:3128/"
https_proxy = "https://localhost:3128"
proxy = "http://localhost:3128/"

➜ gconftool-2 -a /system/http_proxy
 host = http://localhost/
 port = 2000
 use_http_proxy = false
 use_authentication = false
 authentication_password =
 authentication_user =
 ignore_hosts = [localhost,127.0.0.0/8]

gconftool-2 -t string -s /system/http_proxy/host ""
gconftool-2 -u /system/http_proxy/port
gconftool-2 -u /system/http_proxy/host
unset http_proxy

npm install -g @angular/cli@1.7.3 --proxy "http://username:password@proxy_server:proxy_port" --registry http://registry.npmjs.org