jsonhash

A command-line tool to compute hash of file content and filepath, returning the result as JSON.

Supported hashing algorithms

• SHA256: Recommended to avoid collision. By default.
• MD5: Fast (but unsafe) - suitable for files - provided for compatibility/legacy purposes

Features

• Supports both SHA256 and MD5 hash algorithms
• Computes hash of file content
• Computes hash of absolute filepath
• Computes hash of short path (relative to current directory). Useful to create bucket/file ids.
• Returns all information in JSON format. Output and Error messages in JSON format.
• Adopted a request/response style output (>= version 0.2.0)

Usage

• The -a|--alg flag is optional. SHA256 by default

Compute SHA256 hash (default)

jsonhash <filepath>

Compute MD5 hash

jsonhash -a md5 <filepath>

jsonhash --alg md5 <filepath>

Compute SHA256 hash (explicit)

jsonhash -a sha256 <filepath>

jsonhash -alg sha256 <filepath>

Response

The tool returns a JSON object with the following fields:

• request: the request object
• response: the response object
• error: the error object

Notes

request always is present. response and error are mutually exclusive.

Request object

• method: the name of this tool. 'jsonhash'
• version: the version of this tool
• ts: timestamp in nanoseconds when the request was received
• params : contains the parameters as "key":value
  • filepath: filepath you provided in your request
  • alg: Algorithm used (sha256 or md5)
  • id: value provided with --id, else null

Response object

• ts: timestamp in nanoseconds when the request was responded
• absfilepath: Absolute path of the file
• hash: Hash of the file content
• filename: Name of the file
• shortpath: Short path relative to current directory
• pathid: Hash of the absolute filepath
• shortpathid: Hash of the short path

Example

jsonhash test.txt

Returns:

{
  "request": {
    "method": "jsonhash",
    "params": {
      "filepath": "test.txt",
      "id": "1",
      "alg": "md5"
    },
    "ts": 1760367864236976611,
    "version": "0.2.0"
  },
  "response": {
    "ts": 1760367864237186637,
    "absfilepath": "/tmp/jsonhash/test.txt",
    "hash": "9458edef495a29ee98b40a63ed80e9b7",
    "filename": "test.txt",
    "shortpath": "jsonhash/test.txt",
    "pathid": "50b53521888c464428cbb6189ef50602",
    "shortpathid": "d746f98d3344150895a94a752349ce82"
  }
}

Error messages

• Error messages are provided in json format

error message will contain: code: code at integer message: error message as String

Code	Value	Description
3	HASH-ALGORITHM-INVALID	incorrect / unsupported hash algorithm
5	NOT-A-FILE	The filepath is not a file (Directories are not supported)
6	FILE-DOES-NOT-EXIST	The filepath does not exist. No such address: The specified address is unavailable.
66	FILE-OPENING-ERROR	file cannot be opened
70	HASH-DIGEST-COMPUTATION-ERROR	An error occured during the computation of the hash digest

{
  "request": {
    "method": "jsonhash",
    "params": {
      "filepath": "/temp/non-existing-file",
      "id": null,
      "alg": "sha256"
    },
    "ts": 1760368083128138305,
    "version": "0.2.0"
  },
  "error": {
    "code": 6,
    "message": "FILE-DOES-NOT-EXIST"
  }
}

Dependencies

• Rust
• sha2 crate for SHA256 hashing
• md5 crate for MD5 hashing
• clap for command-line argument parsing
• serde for JSON serialization
• tempfile for testing

Building

cargo build --release

Testing

cargo test

• A test.txt sample file is included: test.txt
• A bash test script that uses the sample file is included: test.sh

License

MIT or Apache2

Author

David HEURTEVENT - frua.fr

Changelog

• Version 0.2.0 : Breaking compatibility with v.0.1.x : New JSON request-reponse style with versioning and timestamps (consistent with the jfsm library).