README: updated

A production-ready Python CLI tool for analyzing log files, summarizing errors, warnings, and key metrics. Designed for DevOps, SRE, and developers who need to quickly understand what's happening in their log files.

README: updated# Features

• Multi-format Log Parsing: Automatic detection and parsing of:
  • Syslog (RFC 3164/5424)
  • JSON structured logs (cloud-native formats)
  • Apache/Nginx access logs
  • Generic timestamp-based logs
• Intelligent Analysis:
  • Log level distribution (ERROR, WARNING, INFO, DEBUG, CRITICAL)
  • Error grouping with pattern normalization
  • Time-based distribution analysis
  • Source/component counting
• Flexible Output:
  • Text (human-readable)
  • JSON (machine-readable, perfect for automation)
  • Table (ASCII formatted)
• Powerful Filtering:
  • Filter by log level
  • Regex pattern matching
  • Time range filtering
• Performance:
  • Streaming for large files
  • Gzip compressed file support
  • Auto-detection of log format

README: updated# Installation

README: updated## From PyPI (Recommended)

pip install log-analyzer-cli

README: updated## From Source

git clone https://github.com/HrachShah/log-analyzer-cli.git
cd log-analyzer-cli
pip install -e .

README: updated## Development Installation

pip install -e ".[dev]"

README: updated# Quick Start

Analyze a log file with default settings:

log-analyzer-cli analyze /var/log/syslog

Output to JSON format:

log-analyzer-cli analyze /var/log/syslog -o json

Filter by log level:

log-analyzer-cli analyze /var/log/syslog -l ERROR,WARNING

README: updated# Usage

README: updated## Commands

README: updated### analyze

Analyze a log file and summarize errors, warnings, and metrics.

log-analyzer-cli analyze [OPTIONS] FILE

Options:

Option	Description
-f, --format	Log format (auto, json, syslog, apache, generic)
-o, --output	Output format (text, json, table)
-v, --verbose	Include detailed output
--no-group	Disable error grouping
-l, --levels	Comma-separated list of log levels to include
-p, --pattern	Regex pattern to filter log lines
--start-time	Filter entries after this timestamp (YYYY-MM-DD HH:MM:SS)
--end-time	Filter entries before this timestamp (YYYY-MM-DD HH:MM:SS)

Examples:

README: updated
log-analyzer-cli analyze /var/log/syslog

README: updated
log-analyzer-cli analyze /var/log/app.log -o json

README: updated warnings only
log-analyzer-cli analyze /var/log/app.log -l ERROR,WARNING

README: updated pattern
log-analyzer-cli analyze /var/log/app.log -p "database.*failed"

README: updated-based filtering
log-analyzer-cli analyze /var/log/app.log --start-time "2025-03-20 10:00:00" --end-time "2025-03-20 12:00:00"

README: updated error details
log-analyzer-cli analyze /var/log/app.log -v

README: updated### formats

List supported log formats.

log-analyzer-cli formats

README: updated## Examples

README: updated### Analyzing a Syslog File

$ log-analyzer-cli analyze examples/syslog-sample.log

============================================================
LOG ANALYSIS REPORT
============================================================

Total Lines:     32
Parsed Entries:  32

----------------------------------------
LOG LEVEL DISTRIBUTION
----------------------------------------
  CRITICAL   :      1 (  3.1%)
  ERROR      :     10 ( 31.2%)
  WARNING    :      5 ( 15.6%)
  INFO       :     16 ( 50.0%)

----------------------------------------
TOP ERROR GROUPS
----------------------------------------

1. Pattern: <NUM><NUM> kernel: <NUM><NUM><NUM> Out of memory
   Count: 1
   Time Range: 2025-03-20 10:30:00 to 2025-03-20 10:30:00

2. Pattern: systemd<NUM>: Failed to start Application Service
   Count: 1
...

============================================================

README: updated### Analyzing JSON Logs

$ log-analyzer-cli analyze examples/app-json.log -o json
{
  "summary": {
    "total_lines": 32,
    "parsed_entries": 32,
    "parse_errors": 0
  },
  "level_counts": {
    "INFO": 14,
    "DEBUG": 5,
    "WARNING": 4,
    "ERROR": 8,
    "CRITICAL": 1
  },
  "error_groups": [...]
}

README: updated### Analyzing Apache Access Logs

$ log-analyzer-cli analyze examples/apache-sample.log -o table
+------------------------------------------------------------+
|                     LOG ANALYSIS SUMMARY                   |
+------------------------------------------------------------+
| Metric                          |                     Value |
+------------------------------------------------------------+
| Total Lines                    |                        32 |
| Parsed Entries                 |                        32 |
+------------------------------------------------------------+
...

README: updated# Configuration

README: updated## Log Format Detection

Log Analyzer CLI automatically detects the log format based on the content. You can also manually specify the format using the --format option:

• auto - Automatically detect format (default)
• json - JSON structured logs
• syslog - Syslog format
• apache - Apache/Nginx access logs
• generic - Generic timestamp-based logs

README: updated## Environment Variables

No environment variables are required. All configuration is done via command-line options.

README: updated# Project Structure

log-analyzer-cli/
├── src/log_analyzer_cli/          README: updated
│   ├── __init__.py               README: updated
│   ├── cli.py                    README: updated
│   ├── analyzer.py               README: updated
│   ├── utils.py                  README: updated
│   ├── parsers/                  README: updated
│   │   ├── base.py              README: updated
│   │   ├── syslog.py           README: updated
│   │   ├── json_log.py         README: updated
│   │   ├── apache.py           README: updated/Nginx parser
│   │   └── generic.py          README: updated
│   └── formatters/              README: updated
│       ├── text.py              README: updated
│       ├── json.py              README: updated
│       └── table.py             README: updated
├── tests/                        README: updated
│   ├── test_parsers.py
│   ├── test_analyzer.py
│   └── test_cli.py
├── examples/                      README: updated
│   ├── syslog-sample.log
│   ├── app-json.log
│   ├── apache-sample.log
│   ├── mixed.log
│   └── error-heavy.log
├── .github/                       README: updated
│   ├── workflows/                README: updated/CD workflows
│   └── ISSUE_TEMPLATE/           README: updated
├── pyproject.toml                README: updated
├── README.md                      README: updated
├── CHANGELOG.md                   README: updated
├── CONTRIBUTING.md                README: updated
├── LICENSE                        README: updated
└── SECURITY.md                   README: updated

README: updated# Development

README: updated## Requirements

• Python 3.10+
• click>=8.0.0

README: updated## Development Requirements

• pytest>=7.0.0
• pytest-cov>=4.0.0
• black>=23.0.0
• mypy>=1.0.0
• flake8>=6.0.0

README: updated## Running Tests

pytest tests/

README: updated## Code Formatting

black src/ tests/

README: updated## Type Checking

mypy src/

README: updated# Contributing

Contributions are welcome! Please see CONTRIBUTING.md for detailed guidelines.

README: updated# License

MIT License - see LICENSE file for details.

README: updated# Related Projects

• lnav - Advanced log file viewer
• goaccess - Real-time web log analyzer
• flog - Fake log generator

README: updated# Keywords

log analyzer, log parser, cli tool, syslog, json logs, apache logs, error analysis, log metrics, devops, sre, logging fix README: updated