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Compare archives and SFTP folders ​

A side of a comparison does not have to be a folder on your disk. It can be a folder inside an archive, or a folder on a server you reach over SFTP. You can mix them: a local folder on the left and a server on the right, for example.

Both are chosen from the Other sources menu on a side's card on the home screen.

Compare inside an archive ​

  1. On the home screen, select Folders (or Files).

  2. On the Left or Right card, open Other sources and choose Archive….

  3. Pick the archive and select Open archive.

  4. Browse to the folder (or file) inside it and select Use this folder (or Use this file).

  5. Fill the other side and select Compare.

DeltaView opens zip archives and tar archives, plain or compressed with gzip, bzip2 or xz (.tar.gz, .tar.bz2, .tar.xz). Zip-based files such as .jar open too.

Things to know:

  • Archives are read-only. You can copy from an archive to the other side, but not into it. To change files in an archive, extract it first.
  • Password-protected entries cannot be read.
  • To read a compressed tar archive, DeltaView may unpack it into a temporary file, which it deletes when the archive is closed.

Compare a folder on a server ​

SFTP is file transfer over SSH, the same protocol you use to log in to a server remotely. You need the server's address, a user name, and either a password or a private key.

  1. On a side's card, open Other sources and choose Remote (SFTP)….

    The Connect to a server dialog opens.

  2. Enter the Host. You can type user@server:2222 to fill the user name and port at the same time.

  3. Check Port (22 unless your server uses another) and User name.

  4. Choose how to sign in:

    • Password: type your password.
    • Private key: select Choose… and pick your private key file (not the .pub file). Enter the Passphrase if the key has one.

  5. Leave Save this connection on if you want the server listed under Saved next time.

    Only the host, port, user name, sign-in method and key file path are saved. Passwords and passphrases are never saved.

  6. Select Connect.

  7. The first time you connect to a server, DeltaView asks Trust this host? and shows the server's key fingerprint. Check it, then select Trust and connect.

  8. Browse to the folder or file and select Use this folder or Use this file.

After that, the comparison works like a local one. Saving a file, copying entries or synchronizing writes to the server.

WARNING

Changes you make on a server side are real: saving overwrites the remote file, and deleting or mirroring removes remote files. They cannot be undone from DeltaView.

Why DeltaView asks about the host key ​

Every SSH server has a host key that identifies it. The fingerprint is a short form of that key. Confirming it the first time protects you from connecting to an impostor.

  • To verify a fingerprint, ask the server's administrator, or run ssh-keygen -lf on the server's host key file. Nothing is sent to the server until you confirm.
  • If your SSH client already trusts that key in ~/.ssh/known_hosts, the dialog says so. DeltaView only reads that file; it keeps its own list.
  • If a server you trusted later presents a different key, DeltaView refuses to connect and sends nothing: no password, no key. The dialog is titled "The identity of … has changed".

DANGER

A changed host key can mean the server was reinstalled, or that someone is intercepting the connection. Do not continue unless the server's administrator confirms the new fingerprint. If the change is legitimate, select Known hosts…, remove the old key, and connect again.

Manage saved servers and keys ​

  • In the connect dialog, each entry under Saved has Forget this connection.
  • Known hosts… lists the servers whose identity you confirmed, with fingerprint and date. Remove this key makes the next connection ask again.

Passwords and passphrases you type are kept in memory so that another comparison on the same server does not ask again. They are forgotten when DeltaView closes.

Private keys ​

DeltaView reads OpenSSH private keys, and PEM keys of type RSA or EC. If you installed the snap, pick the key with the file chooser: the snap cannot read ~/.ssh on its own.

Next steps ​