You can make a alias in your ~/.bashrc file :

alias curl="curl -x <proxy_host>:<proxy_port>" 

Another solution is to use (maybe the better solution) the ~/.curlrc file (create it if it does not exist) :

proxy = <proxy_host>:<proxy_port> 

You can make a alias in your ~/.bashrc file :

alias curl="curl -x <proxy_host>:<proxy_port>" 

Another solution is to use (maybe the better solution) the ~/.curlrc file (create it if it does not exist) :

proxy = <proxy_host>:<proxy_port>