# How Holehe's Update Checker Compares Local and PyPI Versions

> Learn how Holehe's update checker compares local and PyPI versions. It reads your local version, queries PyPI for the latest release, and uses packaging to detect updates.

- Repository: [Palenath/holehe](https://github.com/megadose/holehe)
- Tags: internals
- Published: 2026-08-15

---

**Holehe compares versions by reading `__version__` from [`holehe/__init__.py`](https://github.com/megadose/holehe/blob/main/holehe/__init__.py), querying the PyPI JSON API for the latest release, and using `packaging.version.parse` to determine if an update is available.**

Holehe is an OSINT tool for finding accounts by email address across multiple platforms. According to the megadose/holehe source code, the tool includes a lightweight update checker that runs automatically on startup to ensure users operate the latest version. This article explains exactly how the version comparison works, where the logic lives, and how you can inspect or customize it.

## Where the Update Checker Lives

The update checking mechanism is implemented in **[`holehe/core.py`](https://github.com/megadose/holehe/blob/main/holehe/core.py)** within the `check_update` function (lines 65-87). The checker performs a **blocking HTTP request** to PyPI every time the CLI initializes, which can add latency but guarantees users receive timely upgrade notifications.

The function sits near the CLI entry point:

```python

# holehe/core.py

if __name__ == "__main__":
    # ... argument parsing ...

    check_update()          # <-- version comparison triggers here

    # ... main program execution ...

```

When `check_update()` detects a newer release, it prints an upgrade message and **exits the program immediately** rather than allowing outdated code to run.

## Step-by-Step Version Comparison Process

### Step 1: Read the Local Version

The local version string is defined in **[`holehe/__init__.py`](https://github.com/megadose/holehe/blob/main/holehe/__init__.py)** as a module-level constant:

```python

# holehe/__init__.py line 1

__version__ = "1.61"

```

This value is hardcoded during the release process and imported by [`core.py`](https://github.com/megadose/holehe/blob/main/core.py) for comparison.

### Step 2: Fetch the Latest Version from PyPI

The checker queries the public PyPI JSON API endpoint:

```python
import requests

url = "https://pypi.org/pypi/holehe/json"
response = requests.get(url)
pypi_data = response.json()
latest_version = pypi_data["info"]["version"]  # e.g., "1.62"

```

The `info.version` field contains the string of the most recently published release.

### Step 3: Parse and Compare Versions

Both version strings are converted to comparable objects using **`packaging.version.parse`**:

```python
from packaging.version import parse
from holehe import __version__

local = parse(__version__)
remote = parse(latest_version)

if remote > local:
    print(f"A new version of holehe is available ({latest_version}). Run:")
    print("    pip install -U holehe")
    exit(0)  # Exit to force upgrade

```

The `packaging` library handles complex versioning schemes (e.g., `1.61`, `1.61.post1`, `2.0.dev0`) correctly, making simple string comparison unnecessary.

## What Users See

### When an Update is Available

```bash
$ holehe -u alice@example.com
Holehe has just been updated, you can restart it.
Run: pip install -U holehe

```

The program terminates after displaying this message.

### When Running the Latest Version

No output appears; the CLI proceeds immediately to email checking.

## Manually Triggering the Update Check

You can invoke the checker independently in scripts:

```python
from holehe.core import check_update

check_update()  # Exits if update needed, returns silently if current

```

Or simulate the PyPI query yourself:

```python
import json
import urllib.request
from packaging.version import parse
from holehe import __version__

url = "https://pypi.org/pypi/holehe/json"
with urllib.request.urlopen(url) as resp:
    data = json.load(resp)

remote = parse(data["info"]["version"])
local = parse(__version__)

print(f"Local: {local}")
print(f"PyPI:  {remote}")
print(f"Update needed: {remote > local}")

```

## Key Source Files

| File | Purpose | Location |
|------|---------|----------|
| [`holehe/__init__.py`](https://github.com/megadose/holehe/blob/main/holehe/__init__.py) | Defines `__version__` constant | Line 1 |
| [`holehe/core.py`](https://github.com/megadose/holehe/blob/main/holehe/core.py) | Implements `check_update()` and CLI entry point | Lines 65-87 |
| [`setup.py`](https://github.com/megadose/holehe/blob/main/setup.py) | Declares package metadata for PyPI publication | Version must match [`__init__.py`](https://github.com/megadose/holehe/blob/main/__init__.py) |

These three files form the complete update notification pipeline: [`__init__.py`](https://github.com/megadose/holehe/blob/main/__init__.py) provides the source of truth, [`core.py`](https://github.com/megadose/holehe/blob/main/core.py) performs the comparison, and [`setup.py`](https://github.com/megadose/holehe/blob/main/setup.py) ensures PyPI publishes the correct version string.

## Configuration and Limitations

The current implementation has several characteristics worth noting:

- **No disable option** — the check runs unconditionally on every CLI startup
- **Blocking I/O** — slow or unavailable network connections delay tool execution
- **Hard exit on mismatch** — the program terminates rather than warn-and-continue
- **No caching** — PyPI is queried every time, not just once per day

Users requiring offline operation or custom behavior must modify [`holehe/core.py`](https://github.com/megadose/holehe/blob/main/holehe/core.py) directly or patch the `check_update` import.

## Summary

- Holehe's update checker is implemented in **[`holehe/core.py`](https://github.com/megadose/holehe/blob/main/holehe/core.py)** as the `check_update()` function
- The **local version** originates from **[`holehe/__init__.py`](https://github.com/megadose/holehe/blob/main/holehe/__init__.py)** (`__version__`)
- The **PyPI version** is retrieved from `https://pypi.org/pypi/holehe/json`
- **`packaging.version.parse`** enables semantically correct version comparison
- The program **exits immediately** when a newer version is detected, forcing the user to upgrade

## Frequently Asked Questions

### How can I skip the update check in holehe?

The current megadose/holehe source code does not provide a command-line flag to disable the update check. To bypass it, you must either modify [`holehe/core.py`](https://github.com/megadose/holehe/blob/main/holehe/core.py) to comment out the `check_update()` call or run holehe as a library import rather than through the CLI entry point.

### Why does holehe exit instead of warning about updates?

According to the implementation in [`holehe/core.py`](https://github.com/megadose/holehe/blob/main/holehe/core.py), the `exit(0)` call ensures users do not accidentally run outdated code that may contain broken modules or missing features. This enforcement approach prioritizes consistency over convenience.

### What happens if PyPI is unreachable when holehe starts?

The `check_update()` function performs a blocking HTTP request without explicit timeout handling or fallback logic. Network failures will likely raise an exception and prevent the tool from starting until connectivity is restored or the code is patched.

### Does holehe respect semantic versioning in its update checks?

Yes. The use of `packaging.version.parse` in [`holehe/core.py`](https://github.com/megadose/holehe/blob/main/holehe/core.py) ensures proper handling of semantic versions including pre-releases, post-releases, and development versions. This allows accurate comparison of version strings beyond simple lexical ordering.