Diff of remote files

a) Process substitution (bash)

_$: diff <(ssh host1.com 'cat /tmp/file-dev') <(ssh host2.com 'cat /tmp/file-prod') > file-diff

b) vimdiff

_$: vimdiff scp://host1.com/tmp/file-dev scp://host2.com/tmp/file-prod
_$: vimdiff <(ssh host1.com 'cat /tmp/file-dev') <(ssh host2.com 'cat /tmp/file-prod')