Zabbix

//go:build linux

// +build linux

​

/*

** Zabbix

** Copyright (C) 2001-2023 Zabbix SIA

**

** This program is free software; you can redistribute it and/or modify

** it under the terms of the GNU General Public License as published by

** the Free Software Foundation; either version 2 of the License, or

** (at your option) any later version.

**

** This program is distributed in the hope that it will be useful,

** but WITHOUT ANY WARRANTY; without even the implied warranty of

** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

** GNU General Public License for more details.

**

** You should have received a copy of the GNU General Public License

** along with this program; if not, write to the Free Software

** Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

**/

​

package procfs

​

import (

    "bytes"

    "errors"

    "fmt"

    "strconv"

    "strings"

    "syscall"

)

​

const (

    kB = 1024

    mB = kB * 1024

    gB = mB * 1024

    tB = gB * 1024

)

​

// GetMemory reads /proc/meminfo file and returns and returns the value in bytes for the

// specific memory type. Returns an error if the value was not found, or if there is an issue

// with reading the file or parsing the value.

func GetMemory(memType string) (mem uint64, err error) {

    meminfo, err := ReadAll("/proc/meminfo")

    if err != nil {

        return mem, fmt.Errorf("cannot read meminfo file: %s", err.Error())

    }

​

    var found bool

    mem, found, err = ByteFromProcFileData(meminfo, memType)

    if err != nil {

        return mem, fmt.Errorf("cannot get the memory amount for %s: %s", memType, err.Error())

    }

​

    if !found {

        return mem, fmt.Errorf("cannot get the memory amount for %s", memType)

    }

​

    return

}

​

// ReadAll reads all data from a file. Returns an error if there is an issue with reading the file or

// writing the output.

func ReadAll(filename string) (data []byte, err error) {

    fd, err := syscall.Open(filename, syscall.O_RDONLY, 0)

    if err != nil {

        return

    }

    defer syscall.Close(fd)

    var buf bytes.Buffer

    b := make([]byte, 2048)

    for {

        var n int

        if n, err = syscall.Read(fd, b); err != nil {

            if errors.Is(err, syscall.EINTR) {

                continue

            }

            return

        }

​

        if n == 0 {

            return buf.Bytes(), nil

        }

        if _, err = buf.Write(b[:n]); err != nil {

            return

        }

    }

}

​

// ByteFromProcFileData returns the value in bytes of the provided value name from the provided