Sigar（全称System Information Gatherer And Reporter，即系统信息收集报表器），它提供了一个开源的跨平台的收集计算机硬件和操作系统信息的API（该API底层接口用C语言编写）.

Kamon Sigar Loader

Provides convenient self-contained Sigar classes with native library deployment and provisioning mechanism with JDK-only dependencies for the following common use cases:

• Java Agent: automatic extract/load at JVM start time
• Programmatically: embedded library extraction
• Framework Contract: OSGI bundle activation

To load as JVM java agent:

#
# Extract to default location: ${user.dir}/native
java -javaagent:/path/to/sigar-loader.jar ...

#
# Extract to provided library extract location.
java -javaagent:/path/to/sigar-loader.jar=kamon.sigar.folder=/path/to/library/extract/folder ...

Sigar loader agent can also be provided via JVM attach API

To load programmatically from your code:

// Required imports.
		import java.io.File;
		import org.hyperic.sigar.Sigar;
		import kamon.sigar.SigarProvisioner;

// Extract to default location: ${user.dir}/native 
		SigarProvisioner.provision();
		final Sigar sigar = new Sigar();

// Extract to user provided library extract location.
		final File location = new File("target/native");
		SigarProvisioner.provision(location);
		final Sigar sigar = new Sigar();

To load during OSGI bundle activation:

karaf@root()> bundle:install mvn:io.kamon/sigar-loader/1.6.5-rev001

Default extract location

Default library extract location used by

• java -javaagent:/path/to/sigar-loader.jar and
• SigarProvisioner.provision()

will be selected in the following priority order:

1. environment variable KAMON_SIGAR_FOLDER
2. system property kamon.sigar.folder
3. hard coded ${user.dir}/native

Extract location in OSGI

Bundle activator will use framework persistent bundle storage location.

Repeated provision attempts

Sigar loader ensures that native library is loaded exactly once.