sftp -oPort= -oIdentityFile=/root/.ssh/user.priv user@39.39.100.100

-o ssh_option

         Can be used to pass options to ssh in the format used in ssh_config().  This is useful for specifying options for which there is no separate sftp command-line flag.  For exam-

         ple, to specify an alternate port use: sftp -oPort=.  For full details of the options listed below, and their possible values, see ssh_config().

              AddressFamily

               BatchMode

               BindAddress

               ChallengeResponseAuthentication

               CheckHostIP

               Cipher

               Ciphers

               Compression

               CompressionLevel

               ConnectionAttempts

               ConnectTimeout

               ControlMaster

               ControlPath

               GlobalKnownHostsFile

               GSSAPIAuthentication

               GSSAPIDelegateCredentials

               HashKnownHosts

               Host

               HostbasedAuthentication

               HostKeyAlgorithms

               HostKeyAlias

               HostName

               IdentityFile

               IdentitiesOnly

               KbdInteractiveDevices

               LogLevel

               MACs

               NoHostAuthenticationForLocalhost

               NumberOfPasswordPrompts

               PasswordAuthentication

               PKCS11Provider

               Port

               PreferredAuthentications

               Protocol

               ProxyCommand

               PubkeyAuthentication

               RekeyLimit

               RhostsRSAAuthentication

               RSAAuthentication

               SendEnv

               ServerAliveInterval

               ServerAliveCountMax

               StrictHostKeyChecking

               TCPKeepAlive

               UsePrivilegedPort

               User

               UserKnownHostsFile

               VerifyHostKeyDNS