Unix Command - compare files line by line - diff

Como comparar dois arquivos em servidores diferentes?
How you can compare two files in different servers?

 - *Unix:  utilize este comando:
 - *Unix:  you can do this command:

ssh login@remote_ip "cat ~/remote_filename"|diff ~/local_filename -
ssh guest@192.168.0.15 "cat ~/.profile" | diff ~/.profile -