hashit

A tiny, dependency-free Go CLI to hash a file or an entire directory tree with excludes.

• Default algorithm: SHA-256
• Algorithms: sha256, sha512, sha1, md5
• Exclude files/folders with simple patterns
• Deterministic directory digest (stable fingerprint)
• Optional compact output and hash-only mode

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Install

From source (recommended)

# Inside repo root
go mod tidy
go build -o hashit
# or install to $GOBIN (on your PATH)
go install .

Cross-compile (example)

GOOS=linux GOARCH=amd64 go build -o hashit

Using the Makefile

make           # build ./hashit
make install   # go install
make tidy      # go mod tidy
make clean     # remove ./hashit

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Usage

hashit [flags] <path>

<path> can be a file or a directory. If it’s a directory, hashit recursively walks all subfolders (unless excluded), produces per-file hashes when --list is enabled, and always prints a final directory digest (a single hash that represents the entire directory state).

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CLI Options

Flag	Type	Default	Description
--algo	string	sha256	Hash algorithm: sha256, sha512, sha1, md5.
--exclude	string (repeatable)	–	Exclusion patterns. Use dir/** to skip a whole subtree, *.ext to skip files by glob, or exact relative paths.
--list	bool	false	When hashing a directory, also print each file’s hash on its own line.
--follow-symlinks	bool	false	Follow file symlinks (directory symlinks are never followed).
--no-name	bool	false	Print only the hash (omit file/dir name).
--short	int	0	Print only the first N hex characters of the hash (0 = full length).
-h, --help	–	–	Show help.

Notes on excludes

• Folder subtree: .git/**, build/**, node_modules/**
• File glob (by basename): *.log, *.tmp
• Full relative path: path/to/file.txt
• Matching is case-sensitive, uses / as separator internally.
• Exclusions apply to both files and directories during the walk.

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Examples

Hash a single file (default SHA-256)

./hashit ./README.md
# 9b1a...c0d1  README.md

Hash a directory (recursive) with directory digest only

./hashit .
# b0e5...7f2c  your-dir-name

Hash a directory and show per-file hashes too

./hashit --list .
# 1a2b... fileA.txt
# 3c4d... sub/fileB.bin
# ...
# e5f6... your-dir-name   <-- directory digest (always printed)

Exclude .git and log files

./hashit --list --exclude ".git/**" --exclude "*.log" .

Choose SHA-512

./hashit --algo sha512 .

Follow file symlinks

./hashit --follow-symlinks .

Print only the hash (omit the name)

./hashit --no-name ./hashit
# 4c33ae55de4760fe9bb4...2276fad36

Compact hashes (first N chars)

./hashit --short 12 ./hashit
# 4c33ae55de47  hashit

./hashit --short 12 --no-name ./hashit
# 4c33ae55de47

Common exclude recipes

# Node / JS projects
./hashit --list   --exclude ".git/**"   --exclude "node_modules/**"   --exclude "*.log"   .

# Go projects
./hashit --list   --exclude ".git/**"   --exclude "bin/**"   --exclude "*.test"   .

# Large repos (skip vendor + build outputs)
./hashit --list   --exclude "vendor/**"   --exclude "build/**"   --exclude "dist/**"   .

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How the directory digest works

When hashing a directory:

1. hashit walks files recursively (deterministically, sorted).
2. It computes each file’s hash using the chosen algorithm.
3. It builds a manifest: lines of "filehash␠␠relative/path ".
4. It hashes that manifest with the same algorithm.
   The result is a stable fingerprint of the directory contents and structure (ignoring excluded files).

This makes it ideal for:

• detecting changes between builds,
• caching, CI invalidation,
• quick integrity checks.

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Tips

• On Windows, use hashit.exe.
• To get the digest only (useful for scripts), add --no-name.
• To emulate “git short hashes,” use --short 12 (or your preferred length).

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Development

# Format and tidy
go fmt ./...
go mod tidy

# Build
go build -o hashit

# Run ad-hoc
go run . --list --exclude ".git/**" .

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License

MIT