1// Protocol Buffers for Go with Gadgets
2//
3// Copyright (c) 2013, The GoGo Authors. All rights reserved.
4// http://github.com/gogo/protobuf
5//
6// Redistribution and use in source and binary forms, with or without
7// modification, are permitted provided that the following conditions are
8// met:
9//
10//     * Redistributions of source code must retain the above copyright
11// notice, this list of conditions and the following disclaimer.
12//     * Redistributions in binary form must reproduce the above
13// copyright notice, this list of conditions and the following disclaimer
14// in the documentation and/or other materials provided with the
15// distribution.
16//
17// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
20// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
21// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
22// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
23// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
27// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28
29package version
30
31import (
32	"fmt"
33	"os/exec"
34	"strconv"
35	"strings"
36)
37
38func Get() string {
39	versionBytes, _ := exec.Command("protoc", "--version").CombinedOutput()
40	version := strings.TrimSpace(string(versionBytes))
41	versions := strings.Split(version, " ")
42	if len(versions) != 2 {
43		panic("version string returned from protoc is separated with a space: " + version)
44	}
45	return versions[1]
46}
47
48func parseVersion(version string) (int, error) {
49	versions := strings.Split(version, ".")
50	if len(versions) != 3 {
51		return 0, fmt.Errorf("version does not have 3 numbers separated by dots: %s", version)
52	}
53	n := 0
54	for _, v := range versions {
55		i, err := strconv.Atoi(v)
56		if err != nil {
57			return 0, err
58		}
59		n = n*10 + i
60	}
61	return n, nil
62}
63
64func less(this, that string) bool {
65	thisNum, err := parseVersion(this)
66	if err != nil {
67		panic(err)
68	}
69	thatNum, err := parseVersion(that)
70	if err != nil {
71		panic(err)
72	}
73	return thisNum <= thatNum
74}
75
76func AtLeast(v string) bool {
77	return less(v, Get())
78}
79