gopkg.in/ubuntu-core/snappy.v0@v0.0.0-20210902073436-25a8614f10a6/osutil/uname.go (about)

     1  // -*- Mode: Go; indent-tabs-mode: t -*-
     2  
     3  /*
     4   * Copyright (C) 2014-2018 Canonical Ltd
     5   *
     6   * This program is free software: you can redistribute it and/or modify
     7   * it under the terms of the GNU General Public License version 3 as
     8   * published by the Free Software Foundation.
     9   *
    10   * This program is distributed in the hope that it will be useful,
    11   * but WITHOUT ANY WARRANTY; without even the implied warranty of
    12   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    13   * GNU General Public License for more details.
    14   *
    15   * You should have received a copy of the GNU General Public License
    16   * along with this program.  If not, see <http://www.gnu.org/licenses/>.
    17   *
    18   */
    19  
    20  package osutil
    21  
    22  var KernelVersion = kernelVersion
    23  
    24  // We have to implement separate functions for the kernel version and the
    25  // machine name at the moment as the utsname struct is either using int8
    26  // or uint8 depending on the architecture the code is built for. As there
    27  // is no easy way to generalise this implements the same code twice (other
    28  // than going via unsafe.Pointer, or interfaces, which are overkill). The
    29  // way to get this solved is by using []byte inside the utsname struct
    30  // instead of []int8/[]uint8. See https://github.com/golang/go/issues/20753
    31  // for details.
    32  
    33  func kernelVersion() string {
    34  	u, err := uname()
    35  	if err != nil {
    36  		return "unknown"
    37  	}
    38  
    39  	// Release is more informative than Version.
    40  	buf := make([]byte, len(u.Release))
    41  	for i, c := range u.Release {
    42  		if c == 0 {
    43  			buf = buf[:i]
    44  			break
    45  		}
    46  		// c can be uint8 or int8 depending on arch (see comment above)
    47  		buf[i] = byte(c)
    48  	}
    49  
    50  	return string(buf)
    51  }
    52  
    53  func MachineName() string {
    54  	u, err := uname()
    55  	if err != nil {
    56  		return "unknown"
    57  	}
    58  
    59  	buf := make([]byte, len(u.Machine))
    60  	for i, c := range u.Machine {
    61  		if c == 0 {
    62  			buf = buf[:i]
    63  			break
    64  		}
    65  		// c can be uint8 or int8 depending on arch (see comment above)
    66  		buf[i] = byte(c)
    67  	}
    68  
    69  	return string(buf)
    70  }
    71  
    72  // MockKernelVersion replaces the function that returns the kernel version string.
    73  func MockKernelVersion(version string) (restore func()) {
    74  	old := KernelVersion
    75  	KernelVersion = func() string { return version }
    76  	return func() {
    77  		KernelVersion = old
    78  	}
    79  }