github.com/ssdev-go/moby@v17.12.1-ce-rc2+incompatible/pkg/parsers/kernel/kernel.go (about)

     1  // +build !windows
     2  
     3  // Package kernel provides helper function to get, parse and compare kernel
     4  // versions for different platforms.
     5  package kernel
     6  
     7  import (
     8  	"errors"
     9  	"fmt"
    10  )
    11  
    12  // VersionInfo holds information about the kernel.
    13  type VersionInfo struct {
    14  	Kernel int    // Version of the kernel (e.g. 4.1.2-generic -> 4)
    15  	Major  int    // Major part of the kernel version (e.g. 4.1.2-generic -> 1)
    16  	Minor  int    // Minor part of the kernel version (e.g. 4.1.2-generic -> 2)
    17  	Flavor string // Flavor of the kernel version (e.g. 4.1.2-generic -> generic)
    18  }
    19  
    20  func (k *VersionInfo) String() string {
    21  	return fmt.Sprintf("%d.%d.%d%s", k.Kernel, k.Major, k.Minor, k.Flavor)
    22  }
    23  
    24  // CompareKernelVersion compares two kernel.VersionInfo structs.
    25  // Returns -1 if a < b, 0 if a == b, 1 it a > b
    26  func CompareKernelVersion(a, b VersionInfo) int {
    27  	if a.Kernel < b.Kernel {
    28  		return -1
    29  	} else if a.Kernel > b.Kernel {
    30  		return 1
    31  	}
    32  
    33  	if a.Major < b.Major {
    34  		return -1
    35  	} else if a.Major > b.Major {
    36  		return 1
    37  	}
    38  
    39  	if a.Minor < b.Minor {
    40  		return -1
    41  	} else if a.Minor > b.Minor {
    42  		return 1
    43  	}
    44  
    45  	return 0
    46  }
    47  
    48  // ParseRelease parses a string and creates a VersionInfo based on it.
    49  func ParseRelease(release string) (*VersionInfo, error) {
    50  	var (
    51  		kernel, major, minor, parsed int
    52  		flavor, partial              string
    53  	)
    54  
    55  	// Ignore error from Sscanf to allow an empty flavor.  Instead, just
    56  	// make sure we got all the version numbers.
    57  	parsed, _ = fmt.Sscanf(release, "%d.%d%s", &kernel, &major, &partial)
    58  	if parsed < 2 {
    59  		return nil, errors.New("Can't parse kernel version " + release)
    60  	}
    61  
    62  	// sometimes we have 3.12.25-gentoo, but sometimes we just have 3.12-1-amd64
    63  	parsed, _ = fmt.Sscanf(partial, ".%d%s", &minor, &flavor)
    64  	if parsed < 1 {
    65  		flavor = partial
    66  	}
    67  
    68  	return &VersionInfo{
    69  		Kernel: kernel,
    70  		Major:  major,
    71  		Minor:  minor,
    72  		Flavor: flavor,
    73  	}, nil
    74  }