logFuse – because errors are beautiful

Making mistakes is beautiful. Learning from them even more so. logFuse turns your messy, screaming error logs into clean, structured output – HTML for humans, JSON for machines.

⚡ Not just a pretty printer – logFuse parses, groups, and structures your logs so you can use them anywhere: on screen, in APIs, or in your data pipeline.

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Quick Example

use e2\logFuse;

$log = new logFuse();
$log->addFile('/var/log/apache/error.log')
    ->setLanguage('en')
    ->setOrder('desc')
    ->setPagination(1, 50);

echo $log->getOutput('html');   // beautiful, themed HTML
echo $log->getOutput('json');   // structured JSON for APIs

One class. Two outputs. Your choice.

🚀 High‑Performance Index Mode (for huge log files)

When working with multi‑gigabyte log files, logFuse automatically builds a persistent byte‑offset index – so it only reads the entries you actually need for the current page.

• No full file scan – Index stores entry start positions.
• Perfect for DESC pagination – Newest page is read directly from the end of the file.
• Index is cached – Reused as long as the log file does not change (size / mtime).
• Custom cache directory – Use setIndexDirectory() to control where indexes are stored.

$log = new logFuse();
$log->setIndexDirectory('/tmp/logfuse_cache')   // optional, default: sys_get_temp_dir()
    ->addFile('/var/log/huge-error.log')
    ->setPagination(1, 100)
    ->setOrder('desc');

// Only the 100 entries of page 1 are read from disk – memory usage stays low
echo $log->getOutput('html');

To force a rebuild of the index (e.g., after manual log file manipulation):

$log->clearIndexCache();

When using addFileContent() with dynamic content, you can provide a stable ID to keep the index cached across requests:

$log->addFileContent($dynamicLog, 'my_custom_id_v1');

HTML MODE – for humans

When you need to see, understand, and debug – right in your browser

🎨 4 built‑in themes

Theme	Vibe
peachy	warm, soft, friendly
light	clean, bright, clinical
dark	night mode, easy on eyes
e2	original techno style

echo logFuse::getCss('dark');

✨ Full CSS customisation

Don't like the colours? Override CSS variables:

:root {
  --lf-rgb-level-error: 255, 80, 80;
  --lf-rgb-datetime-color: 0, 200, 180;
  --lf-rgb-bg-base: 20, 20, 30;
}

Want complete control? The HTML uses clean, semantic .lf-* classes – write your own CSS from scratch.

<ul class="lf-list">
  <li class="lf-entry error">
    <div class="lf-header">...</div>
    <div class="lf-message">...</div>
    <div class="lf-stacktrace">...</div>
  </li>
</ul>

🧠 What you get in HTML

• Coloured log levels (error, warning, info)
• Human‑readable, localised dates (en, de, tr)
• File names and line numbers highlighted
• Stack traces with progress indicators
• Responsive layout – works on desktop and mobile

JSON MODE – for machines

When you need to feed logs into APIs, databases, or monitoring systems.

📦 Structured output

Each log entry becomes a clean, predictable object:

[
  {
    "datetime": "2025-04-18 14:32:11",
    "level": "error",
    "message": "Uncaught Exception: PDOException...",
    "file": "/var/www/app.php",
    "line": 42,
    "stacktrace": [
      "#0 /var/www/db.php(23): PDO->prepare()",
      "#1 /var/www/index.php(12): require_once()"
    ]
  }
]

No regex. No guesswork. Just ready-to-use JSON.

🚀 Real‑world use cases

Use case	How logFuse helps
REST API	Return parsed error logs as JSON endpoint
Database storage	INSERT structured logs into PostgreSQL, MySQL, MongoDB
Centralised logging	Forward JSON to ELK, Datadog, Loki, or Splunk
Alerting	Count errors per hour, trigger alerts on fatal issues
Automated analysis	Find most common stack traces, error frequencies

💡 “JSON output turns logFuse into a data pipeline component – not just a viewer.”

Tabular Data Sources (CSV, SQLite, MySQL)

logFuse can read logs directly from databases and CSV files – perfect for existing log tables.

// From a SQLite table with columns: log_time, log_level, log_message
$log->addTabularSource('sqlite:/var/log/app.db:logs', ['log_time', 'log_level', 'log_message']);

// From a CSV file with header row
$log->addTabularSource('/var/log/export.csv', ['datetime', 'level', 'message'], ['csv_header' => true]);

// From any iterable data (e.g. PDO statement, array) with custom formatter
$log->addTabularData($myRows, fn($row) => "[{$row['date']}] {$row['severity']}: {$row['text']}");

The same parsing, grouping, and formatting applies – your database logs become instantly readable.

🐛 Debug Mode

Enable debug mode to see exactly how logFuse parses your logs, builds the index, and applies pagination.

$log = new logFuse(['debug' => true]);
$log->addFile('/var/log/error.log');
// ... set pagination, order, etc.
echo $log->getOutput('html');

// Output debug log as HTML comment (in HTML mode) or as extra "_debug" key (in JSON mode)
$log->getDebug('output');   // prints to screen
$log->getDebug('log');      // writes to error_log

In the Playground, append ?debug=1 to the URL to see the internal debug output.

Timezone Support

Log timestamps without timezone info? No problem. Set the default timezone in the constructor:

$log = new logFuse(['timezone' => 'Europe/Berlin']);

All dates will be parsed and displayed consistently.

Playground – learn by doing

The playground/ folder contains a live demo that showcases all logFuse features.

Note about Magic Dates: The demo logs use special timestamps like 2111-01-01 11:11:XX (XX = second). These are static placeholders that the playground replaces with relative terms (today, yesterday, …) at display time. This keeps the demo evergreen – you always see “today”, “yesterday”, etc., no matter when you run it. The real logFuse class works with any real timestamp; the magic date trick is only for the playground.

What the playground demonstrates:

• Parsing of Apache, PHP, MySQL, and custom logs
• Switching between HTML and JSON output
• Changing themes, language (en/de/tr), timezone, and order
• Pagination (page size and page number)
• Reading from SQLite (standard 3‑column table) and CSV files
• Automatic replacement of magic dates with relative terms
• Debug mode – add ?debug=1 to see logFuse internals

Open playground/index.php and try it yourself.

No database. No setup. Just beautiful errors.

Installation

No Composer required – copy src/logFuse.php into your project.

Requirements

• PHP ≥ 8.1

Making mistakes is beautiful – really

Every error log is a story. Something went wrong, and now you get to fix it. logFuse helps you read that story with clarity, colour, and structure – whether on screen or in your data pipeline.

💡 “Errors are not failures. They are lessons dressed in red – and JSON.”