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 29 package version 30 31 import ( 32 "fmt" 33 "os/exec" 34 "strconv" 35 "strings" 36 ) 37 38 func 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 48 func 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 64 func 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 76 func AtLeast(v string) bool { 77 return less(v, Get()) 78 } 79