#install unison

$ sudo apt install unison

# synchronizing from local folder "/home/user/sync/" with remote "ssh://user@remotehost.com/" folder "/home/user/sync/" (ssh port 22000)


$ unison -silent -auto -batch /home/user/sync/ ssh://user@remotehost.com//home/user/sync/ \
  -nodeletion ssh://user@remotehost.com//home/user/sync/ \
  -sshargs '-p22000' -logfile /tmp/mylog.txt