pushpop

Easily send files from one computer to another.

Repository layout (new idiomatic Go structure)

• cmd/push: push binary that shares a file via TCP + mDNS (zeroconf).
• cmd/pop: pop binary that discovers an mDNS announcement and downloads the file.
• pkg/discovery: helpers for mDNS discovery (extracting the user and matching IP).
• pkg/transfer: transfer logic (accepting connections, sending files, progress bar).

Quick Usage

1. Build. Both binaries land at the repository root:

./build.sh
# or, by hand:
go build -o push ./cmd/push
go build -o pop ./cmd/pop

Note that go build ./cmd/pop needs the package directory, not cmd/pop/main.go: the command is split across main.go and tui.go.

2. Send a file from machine A:

./push /path/to/file

3. On machine B, receive the file (optionally provide the sender's username):

./pop <username>
# without an argument it looks for a file shared by yourself
./pop --force <username>   # overwrite an existing file without asking

Notes

• The old push/main.go and pop/main.go files have been removed from the repository (their functionalities have been migrated under cmd/).

TODO

• Be able to push a directory.
• Be able to resume an interrupted download.
  • Use a .part suffix for partial downloads.
  • Resume only if the server supports HTTP Range requests; otherwise, restart from the beginning and warn the user.
  • Add a --force option to overwrite existing files without confirmation.
  • Do not handle checksums for now (see below).
• Implement using multiple progress bars (e.g., mpb).
• (Optional) Implement a mechanism to preallocate the final file size for downloads (file reservation).
• (Optional) Add checksum/integrity verification after download (BLAKE3).
• Add IP and username of the user downloading the file (when available) on the push side.
  • Client (pop) now sends the X-PushPop-User header.
  • Server (push) logs start/end of downloads with IP & username, and hash requests.
• Add a TUI (Terminal User Interface) to manage file sharing:
  • Allow the user to stop sharing a file manually.
  • Display active downloads and connections.
  • Blacklist users based on their IP address or username (when available).
• Add daemon mode for push:
  • Implement --daemon or -d flag to run push in the background (not default).
  • Create a control socket (e.g., /tmp/pushpop.sock) for daemon management.
  • Implement push --control to attach a TUI to a running daemon.
  • Implement push --stop to gracefully stop a running daemon.
  • Implement push --status to display information about active daemons.
• Display the user requesting a BLAKE3 in the push output.
• Fix display of the effective user in push (when pop is run from another machine, push should show the real user, not just the requested name).
  • pop now sends its own local user in X-PushPop-User, instead of the name it was asked to look for.
• Update push to use Bubble Tea (TUI on the server side).
• Add a progress bar for downloading the BLAKE3 verification file.
• Add a progress bar for computing the BLAKE3 checksum (file parsing).
• It should be possible to bind to a list of interfaces on the push command. And on the pop command?
• Remove blake package if not used anymore.
• Pop: Move the Init()/Update()/View() functions into a tui.go file.
• Pop: adapt the UI to the current window size.
• Use socket unix when downloading on the same machine.
• Provide multiple signature files: sha256/Blake3/etc.
• Better processing when the file exists and/or the part file exists.
• Use IPV6 addresses eventually.
• Implement TUI (with altScreen?) in push.
• Push should be able to provide multiple files in parrallel.
• Push should launch blake3 signature computation asap.
• Log should not appear in the standard output when DEBUG env var is undefined.

Known (unresolved) Issues:

• When you change the current window size, then the title line gets duplicated.
• Downloading a file through a socket is really slow. (Maybe we should have a longer chunk downloading buffer?)
  • Likely culprit: the .part file is reopened and closed for every 128 KiB chunk, and each chunk makes a full round trip through the Bubble Tea event loop.
• Sometimes the blake verification progress bar keeps staying a 0%, while the actual processing is progressing.
  • The speed tick stopped rescheduling itself in the done && !verifying window, killing the ticker before the verification started.
• The BLAKE3 bar lags well behind the byte counter on fast disks: the spring animation cannot keep up with hashing.