Feature suggestion: checksums

[entangledloops]

I'd love to have the ability to do a quick checksum of two files (or folders) in the left/right pane, doesn't matter which algorithm.

I'm often working on servers where I FTP some medium-large size files (~5 gb) back-and-forth and it would be great to check a box at transfer time to verify sanity.
I know it can't be too much code to implement (*sigh*, nothing's ever easy, I realize that).

Seems like a perfect addition to the "Directory comparison" menu. Didn't see it suggested after briefly searching these forums, but I'll admit I didn't look too hard after a long day of build errors.

[boco]

FTP unfortunately doesn't support this as there's no direct/random access to files on FTP servers. That would mean,

- the FTP server software has to be told by the user to hash the file on the server directly. Unfortunately, such an official feature doesn't exist. There's a draft proposal to the IETF for a HASH command that would allow this - but don't hold your breath, yet.

or

- using one of the unofficial commands in existence (CRC/XCRC, MD5/XMD5, SHA/XSHA etc.). FileZilla software will not use these as their implementation is not standardized and thus ambiguous.

or

- re-download each and any file to check the hash. The burning of resources and the introduced level of uncertainty make that approach effectively useless.

or

- have the server software maintain hash-tables. Could be a viable option for servers with relatively static content, but not for a live, actively used one.


Yes, it's not easy at all, in this case.