blob: a21ba137e39ea5dac3aa6fc0fae8495f822d529d [file] [log] [blame]
// +build !windows
// Package kernel provides helper function to get, parse and compare kernel
// versions for different platforms.
package kernel
import (
"bytes"
"errors"
"fmt"
)
// VersionInfo holds information about the kernel.
type VersionInfo struct {
Kernel int // Version of the kernel (e.g. 4.1.2-generic -> 4)
Major int // Major part of the kernel version (e.g. 4.1.2-generic -> 1)
Minor int // Minor part of the kernel version (e.g. 4.1.2-generic -> 2)
Flavor string // Flavor of the kernel version (e.g. 4.1.2-generic -> generic)
}
func (k *VersionInfo) String() string {
return fmt.Sprintf("%d.%d.%d%s", k.Kernel, k.Major, k.Minor, k.Flavor)
}
// CompareKernelVersion compares two kernel.VersionInfo structs.
// Returns -1 if a < b, 0 if a == b, 1 it a > b
func CompareKernelVersion(a, b VersionInfo) int {
if a.Kernel < b.Kernel {
return -1
} else if a.Kernel > b.Kernel {
return 1
}
if a.Major < b.Major {
return -1
} else if a.Major > b.Major {
return 1
}
if a.Minor < b.Minor {
return -1
} else if a.Minor > b.Minor {
return 1
}
return 0
}
// GetKernelVersion gets the current kernel version.
func GetKernelVersion() (*VersionInfo, error) {
var (
err error
)
uts, err := uname()
if err != nil {
return nil, err
}
release := make([]byte, len(uts.Release))
i := 0
for _, c := range uts.Release {
release[i] = byte(c)
i++
}
// Remove the \x00 from the release for Atoi to parse correctly
release = release[:bytes.IndexByte(release, 0)]
return ParseRelease(string(release))
}
// ParseRelease parses a string and creates a VersionInfo based on it.
func ParseRelease(release string) (*VersionInfo, error) {
var (
kernel, major, minor, parsed int
flavor, partial string
)
// Ignore error from Sscanf to allow an empty flavor. Instead, just
// make sure we got all the version numbers.
parsed, _ = fmt.Sscanf(release, "%d.%d%s", &kernel, &major, &partial)
if parsed < 2 {
return nil, errors.New("Can't parse kernel version " + release)
}
// sometimes we have 3.12.25-gentoo, but sometimes we just have 3.12-1-amd64
parsed, _ = fmt.Sscanf(partial, ".%d%s", &minor, &flavor)
if parsed < 1 {
flavor = partial
}
return &VersionInfo{
Kernel: kernel,
Major: major,
Minor: minor,
Flavor: flavor,
}, nil
}