Initial commit

vendor/github.com/hyperhq/hypercli/pkg/parsers/kernel/kernel.go

@@ -0,0 +1,100 @@
+// +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
+}