sneak
7f75f2ee72
Fix every golangci-lint finding under the repo's standard .golangci.yml (from ~192 down to 0 under the pinned v2.10.1) without changing program behavior: - gochecknoglobals: replace the verbose/quiet/exclude* package globals with an options struct threaded through the command implementations. - err113: introduce package-level sentinel errors and wrap them with %w. - errcheck: check or explicitly discard every previously unchecked error (bar.Add/Finish, deferred Close, verbose writes). - forbidigo: route verbose output through os.Stdout instead of fmt.Print*. - noinlineerr / wsl_v5 / nlreturn / gofmt: split inline error checks and normalize whitespace. - complexity (cyclop/gocognit/nestif): extract small behavior-preserving helpers (runOverPaths, countAndBar, walkSkip, clearOne, checkOne, missingChecksum, reportCheck). - mnd/lll/nonamedreturns/revive/modernize/nilnil: named constants, wrapped lines, unnamed returns, doc comments, SplitSeq, non-(nil,nil) returns. - paralleltest/thelper: mark tests parallel (now race-safe with no shared globals) and add t.Helper(); probe the real xattr key so the guard is accurate. Also make the tests actually runnable in CI rather than skipping: - move the xattr keys into the user.* namespace (user.berlin.sneak.app.*), which Linux requires for regular-file xattrs; macOS treats the whole string as an opaque name, so behavior is unchanged there. - run the Docker builder's checks as an unprivileged user so the permission tests are meaningful (root bypasses file mode bits).
attrsum is a Go 1.22 command-line utility that adds, updates, verifies, and clears per-file file content checksums stored in extended attributes (xattrs) on macOS (APFS) and Linux, released under the WTFPL v2.
Original release 2025-05-08.
Current version 1.0 (2025-05-08).
Getting Started — Quick Build
# prerequisites: Go 1.22+
git clone https://git.eeqj.de/sneak/attrsum.git
cd attrsum
go build -o attrsum .
Install
go install git.eeqj.de/sneak/attrsum@latest # into GOPATH/bin or $(go env GOBIN)
Semantic Versioning 2.0.0 is used for tags.
Usage
# add checksum & timestamp xattrs to every regular file under one or more paths
attrsum sum add DIR1 DIR2 file.txt
# update checksum only when file mtime is newer than stored sumtime
attrsum sum update DIR1 DIR2
# verify checksums, stop on first error
attrsum check DIR1 DIR2
# verify every file, reporting each result, keep going after errors
attrsum -v check --continue DIR1 DIR2
# remove checksum & timestamp xattrs
attrsum clear DIR1 DIR2
# read paths from stdin (use - as argument)
find /data -name "*.jpg" | attrsum sum add -
# quiet mode (suppress progress bar and summary)
attrsum -q sum add DIR
| xattr key | meaning |
|---|---|
user.berlin.sneak.app.attrsum.checksum |
base-58 multihash (sha2-256) |
user.berlin.sneak.app.attrsum.sumtime |
RFC 3339 timestamp of checksum |
Flags:
-v, --verbose— per-file log output-q, --quiet— suppress all output except errors (no progress bar or summary)--exclude PATTERN— skip paths matching rsync/Doublestar glob--exclude-dotfiles— skip any path component that starts with.
All commands display a progress bar with ETA and print a summary report to stderr on completion (unless --quiet is specified).
attrsum never follows symlinks and skips non-regular files (sockets, devices, …).
Why?
Apple APFS and Linux ext3/ext4 store no per-file content checksums, so
silent data corruption can pass unnoticed. attrsum keeps a portable checksum inside each file’s xattrs, providing integrity
verification that travels with the file itself—no external database
required. Now you can trust a USB stick didn't eat your data.
TODO
Future improvements under consideration:
- Dry-run mode (
--dry-run,-n) — show what would be done without making changes - JSON output (
--json) — machine-readable output for scripting and integration - Parallel processing (
-j N) — use multiple goroutines for faster checksumming on large trees - Exit code documentation — formalize and document exit codes for scripting
Contributing
- Author & maintainer: sneak – sneak@sneak.berlin
- Issues / PRs: https://git.eeqj.de/sneak/attrsum/
- Code must pass
go vet,go test ./..., andgo fmt. - No CLA; contributions are under WTFPL v2.
Community & Support
Bug tracker and wiki are in the Gitea repo linked above.
No formal Code of Conduct; be excellent to each other.
License
Everything is permitted. See WTFPL v2.