How to download a certificate from a HTTPS website by OpenSSL

To download a certificate from a HTTPS website by OpenSSL,

use the following command:

openssl s_client -connect www.izeye.com:443

and copy from the following line:

-----BEGIN CERTIFICATE-----

to the following line:

-----END CERTIFICATE-----

and save it as a file like test.pem.

By 'man s_client', you can find the meanings of the options:

s_client - SSL/TLS client program

       -connect host:port
           This specifies the host and optional port to connect to. If not
           specified then an attempt is made to connect to the local host on
           port 4433.

Reference:
http://superuser.com/questions/97201/how-to-save-a-remote-server-ssl-certificate-locally-as-a-file