verisync 1.3.0

Interactive directory/file transfer with SHA-256 checksum verification over SSH

verisync — Interactive Directory Transfer with Checksum Verification

A general-purpose interactive file/directory transfer utility with end-to-end SHA-256 checksum verification over SSH.
Transfer files or directories to a remote server via rsync or tar.gz, then automatically verify every file's integrity — all from a single command.

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Table of Contents

• Features
• Requirements
• Installation
  • Via pip (recommended)
  • Via pipx (isolated)
  • Manual install
• Usage
  • Arguments
  • Examples
• Transfer Steps
• Modes: rsync vs zip
• Contributing
• License

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Features

• 📁 File and directory — transfer a single file or an entire directory tree
• 📦 Batch mode — transfer multiple sources in one run with flexible destination mapping
• ✅ End-to-end SHA-256 verification — a checksum manifest is generated locally and re-verified remotely after transfer
• ♻️ rsync mode (default) — incremental, resumable, and bandwidth-efficient
• 🗜️ Zip mode (--zip) — packs each source into a .tar.gz, uploads, and auto-extracts on the remote
• 🔌 SSH multiplexing — a single SSH control socket is reused across all remote operations, including 2FA/password auth flows
• 📏 Space checks — remote free disk space is measured before transfer; warns if total exceeds 100 GiB
• 🖥️ Interactive + CLI — all parameters can be supplied as CLI flags or entered interactively at runtime
• 🤖 Auto-confirm (-y) — skip prompts for scripted/non-interactive usage
• 🛡️ Disconnect guard — auto-wraps in screen (or tmux) so SSH drops don't kill the transfer
• 🔍 Cross-node session discovery — verisync ls and verisync -r find and reattach to active sessions across login nodes (one-step SSH + screen -r, with shell fallback if the session is gone)
• 🚫 Duplicate-transfer detection — per (source → destination) pair check across active sessions on the same remote; abort, kill the conflicting session, or ignore. Runs before the screen wrap when full config is on the CLI so abort messages reach the terminal
• 🕒 Elapsed time — reports total transfer and verification duration

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Requirements

Requirement	Notes
Bash >= 4.0	Required for string manipulations and set -euo pipefail
rsync	Used for incremental file transfer in default mode
ssh	SSH client with multiplexing (ControlMaster) support
sha256sum	Standard coreutils tool, available on all Linux/macOS systems
bc	Used for human-readable size arithmetic
tar	Only required when using --zip mode

Note: verisync only needs to be installed on the source machine. The remote side requires only sha256sum and standard POSIX shell tools — no remote installation needed.

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Installation

Via pip (recommended)

pip install verisync

This places the verisync command on your PATH.

Via pipx (isolated)

pipx install verisync

Manual install

git clone https://github.com/whats2000/verisync.git
cd verisync
bash verisync.sh --help

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Usage

verisync [OPTIONS]            Start a new transfer
verisync ls                   List active verisync sessions across login nodes
verisync -r | --reattach      Pick an active session and reattach
                              (cross-node sessions: SSH + auto screen -r)

Arguments

Flag	Description
-s, --src <path>	Local source file or directory to transfer (repeat for batch)
-u, --user <user>	Remote SSH username
-H, --host <host>	Remote SSH hostname or IP address
-d, --dest <path>	Remote destination (1 shared dest OR one per --src)
--zip	Pack each source into tar.gz before transferring
-y, --yes	Auto-confirm all prompts (non-interactive mode)
-h, --help	Show usage and exit

Any flag not supplied on the command line will be prompted interactively.

Examples

Interactive mode (prompts for all parameters):

verisync

Fully specified via CLI:

verisync --src /data/project --user alice --host hpc.example.com --dest /scratch/alice/

Batch mode (multiple sources to shared destination):

verisync -s /data/file1.txt -s /data/dir2 -d /remote/shared/ -u alice -H hpc.example.com

Batch mode (1:1 source-to-destination mapping):

verisync -s /local/a -s /local/b -d /remote/x -d /remote/y -u alice -H hpc.example.com

Use zip mode for compressed uploads:

verisync -s /data/project -u alice -H hpc.example.com -d /scratch/alice/ --zip

Non-interactive mode (auto-confirm all prompts):

verisync -s /data/project -u alice -H hpc.example.com -d /scratch/alice/ -y

List active sessions across login nodes:

verisync ls

Reattach to an active session (auto-SSH + screen -r for cross-node):

verisync -r

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Transfer Steps

Step	Description
1	Collect source(s), destination(s), remote user, and host
2	Measure total local size; warn if > 100 GiB
3	Test SSH connectivity; check remote free disk space for each destination
4	For each source: generate SHA-256 checksum manifest
5	For each source: transfer files + manifest via rsync (or tar.gz)
6	For each source: verify checksums remotely
7	Print batch summary (pass/fail per source)

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Modes: rsync vs zip

Feature	rsync (default)	--zip mode
Resumable?	Yes	No
Incremental?	Yes	No
Single archive?	No	Yes (per source)
Compression	-z (inline)	gzip (pre-compressed)
Remote extraction	Not needed	Auto-extracted via tar

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Contributing

Bug reports and pull requests are welcome at github.com/whats2000/verisync.

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License

MIT — see LICENSE for details.