mackerelio/go-osstat

OS system statistics library for Go

Go

421

317 commits

updated Oct 6, 2026

See the code

README

OS system statistics library for Go

This is a library to get system metrics like cpu load and memory usage. The library is created for mackerel-agent.

GoDev Build Status

Example

package main

import (
	"fmt"
	"os"

	"github.com/mackerelio/go-osstat/memory"
)

func main() {
	memory, err := memory.Get()
	if err != nil {
		fmt.Fprintf(os.Stderr, "%s\n", err)
		return
	}
	fmt.Printf("memory total: %d bytes\n", memory.Total)
	fmt.Printf("memory used: %d bytes\n", memory.Used)
	fmt.Printf("memory cached: %d bytes\n", memory.Cached)
	fmt.Printf("memory free: %d bytes\n", memory.Free)
}

Supported OS

loadavguptimecpumemorynetworkdisk i/o
Linuxyesyesyesyesyesyes
Darwinyesyes*1yesyesno
FreeBSDyesyesnoyesyesno
NetBSDyesyesnonoyesno
OpenBSDyesyesnononono
Windowsnoyesnoyesnono

*1: unavailable without cgo

Note for counter values

This library returns the counter value for cpu, network and disk I/O statistics by design. To get the cpu usage in percent, network traffic in kB/s or disk IOPS, sleep for a while and calculate the difference.

package main

import (
	"fmt"
	"os"
	"time"

	"github.com/mackerelio/go-osstat/cpu"
)

func main() {
	before, err := cpu.Get()
	if err != nil {
		fmt.Fprintf(os.Stderr, "%s\n", err)
		return
	}
	time.Sleep(time.Duration(1) * time.Second)
	after, err := cpu.Get()
	if err != nil {
		fmt.Fprintf(os.Stderr, "%s\n", err)
		return
	}
	total := float64(after.Total - before.Total)
	fmt.Printf("cpu user: %f %%\n", float64(after.User-before.User)/total*100)
	fmt.Printf("cpu system: %f %%\n", float64(after.System-before.System)/total*100)
	fmt.Printf("cpu idle: %f %%\n", float64(after.Idle-before.Idle)/total*100)
}

LICENSE

Copyright 2017-2019 Hatena Co., Ltd.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    https://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
go
golang
golang-library
system-information

mackerelio/go-osstat

OS system statistics library for Go

Go

421

317 commits

updated Oct 6, 2026

See the code

README

OS system statistics library for Go

This is a library to get system metrics like cpu load and memory usage. The library is created for mackerel-agent.

GoDev Build Status

Example

package main

import (
	"fmt"
	"os"

	"github.com/mackerelio/go-osstat/memory"
)

func main() {
	memory, err := memory.Get()
	if err != nil {
		fmt.Fprintf(os.Stderr, "%s\n", err)
		return
	}
	fmt.Printf("memory total: %d bytes\n", memory.Total)
	fmt.Printf("memory used: %d bytes\n", memory.Used)
	fmt.Printf("memory cached: %d bytes\n", memory.Cached)
	fmt.Printf("memory free: %d bytes\n", memory.Free)
}

Supported OS

loadavguptimecpumemorynetworkdisk i/o
Linuxyesyesyesyesyesyes
Darwinyesyes*1yesyesno
FreeBSDyesyesnoyesyesno
NetBSDyesyesnonoyesno
OpenBSDyesyesnononono
Windowsnoyesnoyesnono

*1: unavailable without cgo

Note for counter values

This library returns the counter value for cpu, network and disk I/O statistics by design. To get the cpu usage in percent, network traffic in kB/s or disk IOPS, sleep for a while and calculate the difference.

package main

import (
	"fmt"
	"os"
	"time"

	"github.com/mackerelio/go-osstat/cpu"
)

func main() {
	before, err := cpu.Get()
	if err != nil {
		fmt.Fprintf(os.Stderr, "%s\n", err)
		return
	}
	time.Sleep(time.Duration(1) * time.Second)
	after, err := cpu.Get()
	if err != nil {
		fmt.Fprintf(os.Stderr, "%s\n", err)
		return
	}
	total := float64(after.Total - before.Total)
	fmt.Printf("cpu user: %f %%\n", float64(after.User-before.User)/total*100)
	fmt.Printf("cpu system: %f %%\n", float64(after.System-before.System)/total*100)
	fmt.Printf("cpu idle: %f %%\n", float64(after.Idle-before.Idle)/total*100)
}

LICENSE

Copyright 2017-2019 Hatena Co., Ltd.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    https://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
go
golang
golang-library
system-information

Project health

Overall

5.5/10

Maintained

4/10

Code review

10/10
OpenSSF Scorecard

Latest release

v0.2.8 · Jul 8, 2026

Releases this year

2

Significant stargazers

Arve Knudsen

267 followers · starred May 2023

Guoyu Hu

15 followers · starred Apr 2023

pj

98 followers · starred Dec 2020

Luke Thomas

36 followers · starred Dec 2024