HashTo

Being a small forge-wrought tool of TheDevinLabs, for the turning of any file into a hash, and of any hash into a form the eye may read.

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I. Of Its Purpose

A hash, once struck, is a fine thing for a machine to compare — yet a poor thing for a person to inspect. HashTo remedies this. It strikes a hash from any file or stream of bytes and seals it in a compact binary vessel (a .hash file) — algorithm, digest, timestamp, locale, and the size and name of the source all bound together. From that vessel, HashTo can pour the contents out into JSON or YAML, plain and legible, and pour them back in again, restoring the original binary form bit for bit.

No third-party library is called upon. The tool is built entirely of the Go standard library, and answers to none but itself.

II. Of Its Commands

Flag	Short	Purpose
--hash		Strike a hash from a file or from stdin
--to-json		Pour a .hash file out into JSON
--to-yaml		Pour a .hash file out into YAML
--from-json		Pour JSON back into a .hash file
--from-yaml		Pour YAML back into a .hash file
--table-hash FILE		Lay every particular of a .hash file plain upon the table
--input	-i	The file to read
--output	-o	The file to write (- for stdout, on conversions)
--algo	-a	md5, sha1, sha256 (default), or sha512
--help	-h	Show usage
--version	-v	Show version

III. Of Its Use

Strike a hash from a file:

hashto --hash --input photo.png --algo sha256

Strike a hash from whatever comes down the pipe:

cat notes.txt | hashto --hash --output notes.hash

Pour a .hash file into YAML for reading, or JSON if that is your custom:

hashto --to-yaml --input notes.hash
hashto --to-json --input notes.hash --output notes.json

Pour it back into binary form, unchanged:

hashto --from-yaml --input notes.yaml --output rebuilt.hash

Lay every particular bare upon the table:

hashto --table-hash notes.hash

----------------------
File            : notes.hash
Source          : notes.txt
Source Size     : 8214 bytes
Algorithm       : sha256
Digest (hex)    : 9f86d081884c7d659a2feaa0c55ad015a3bf4f1b2b0b822cd15d6c15b0f00a08
Digest (base64) : n4bQgYhMfWWaL+qgxVrQFaO/TxsrCwiC0Y1sFbDwCgg=
Created         : 2026-07-02T09:14:03Z
Locale/Charset  : en_US.UTF-8
----------------------

IV. Of the .hash Format

A .hash file is a small binary vessel, laid out thus:

"HTOH" magic (4 bytes)
version byte
algorithm byte   (1=md5, 2=sha1, 3=sha256, 4=sha512)
digest length    (uint16) + digest bytes
timestamp        (int64, unix seconds)
locale length    (uint16) + locale bytes
source length    (uint16) + source filename bytes
source size      (int64, bytes read to produce the digest)

Nothing here is left to guesswork; the JSON and YAML forms carry the same fields under plain names, and either may be turned back into the binary form without loss.

V. Of Its Building

make build      # builds ./hashto for the host platform
make install     # installs to $PREFIX/bin (or /usr/local/bin)
make clean       # sweeps away build artifacts and scratch hashes

Cross-compilation needs no ceremony beyond the standard GOOS/GOARCH of Go itself:

GOOS=windows GOARCH=amd64 go build -o hashto.exe .

Team

• CoolyDucks (Abdullah)