Sys::Monitor::Lite

A lightweight system monitoring toolkit. Using the script/sys-monitor-lite script you can collect CPU, memory, disk capacity, disk I/O, network, and other Linux metrics in JSON format. It runs entirely on Perl with no external dependencies.

Features

• Lightweight implementation that simply reads data from /proc
• Collects CPU, load average, memory, disk capacity, disk I/O, network, and system information
• Allows you to choose which metrics to collect from the CLI
• Supports JSON / JSON Lines output, with --pretty for formatted JSON
• Reusable as a module (Sys::Monitor::Lite) so scripts can integrate it easily

Installation

To install from CPAN:

cpanm Sys::Monitor::Lite

To use it directly from the repository:

git clone https://github.com/yourname/sys-monitor-lite.git
cd sys-monitor-lite
perl Makefile.PL && make install

You can also run the scripts in the repository directly without installing.

Usage (Command Line)

Collect metrics once

script/sys-monitor-lite --once

Collect continuously at 5-second intervals (default)

script/sys-monitor-lite --interval 5

Limit the metrics collected and output as JSON Lines

script/sys-monitor-lite --interval 10 --collect cpu,mem,disk --output jsonl

Key options

| Option | Description | | ----------- | ---- | | --interval <seconds> | Interval for repeated collection. Defaults to 5 seconds. Values ≤ 0 collect only once. | | --once | Collects metrics once. Equivalent to omitting --interval. | | --collect <list> | Comma-separated list selecting from system,cpu,load,mem,disk,disk_io,net. | | --output <format> | Choose json (default) or jsonl. | | --pretty | Format JSON output (jsonl ignores this). | | --help | Show help (POD). |

The JSON output can be combined with tools such as jq or jq-lite.

script/sys-monitor-lite --once | jq '.mem.used_pct'

Using as a Perl Module

use Sys::Monitor::Lite qw(collect_all to_json);

my $metrics = collect_all();
print to_json($metrics, pretty => 1);

Instead of collect_all, you can pass an array reference like collect(["cpu", "mem"]) to specify which metrics to gather.

Available Data

• system: OS name, kernel version, hostname, architecture, uptime (seconds)
• cpu: Number of cores and aggregate CPU utilization (difference over ~100 ms)
• load: Load average over 1, 5, and 15 minutes
• mem: Total, used, and free memory, plus swap usage
• disk: Total capacity, used capacity, and utilization for each mount point
• disk_io: Block device read/write I/O counters (bytes, sectors, operations)
• net: Received/sent bytes and packets per interface

License

MIT License

Author

Shingo Kawamura (@kawamurashingo)