1  // Copyright (c) 2013 The btcsuite developers
 2  // Use of this source code is governed by an ISC
 3  // license that can be found in the LICENSE file.
 4  
 5  package main
 6  
 7  import (
 8  	"bytes"
 9  	"fmt"
10  	"strings"
11  )
12  
13  // semanticAlphabet
14  const semanticAlphabet = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz-"
15  
16  // These constants define the application version and follow the semantic
17  // versioning 2.0.0 spec (http://semver.org/).
18  const (
19  	appMajor uint = 0
20  	appMinor uint = 12
21  	appPatch uint = 0
22  
23  	// appPreRelease MUST only contain characters from semanticAlphabet
24  	// per the semantic versioning spec.
25  	appPreRelease = "beta"
26  )
27  
28  // appBuild is defined as a variable so it can be overridden during the build
29  // process with '-ldflags "-X main.appBuild foo' if needed.  It MUST only
30  // contain characters from semanticAlphabet per the semantic versioning spec.
31  var appBuild string
32  
33  // version returns the application version as a properly formed string per the
34  // semantic versioning 2.0.0 spec (http://semver.org/).
35  func version() string {
36  	// Start with the major, minor, and patch versions.
37  	version := fmt.Sprintf("%d.%d.%d", appMajor, appMinor, appPatch)
38  
39  	// Append pre-release version if there is one.  The hyphen called for
40  	// by the semantic versioning spec is automatically appended and should
41  	// not be contained in the pre-release string.  The pre-release version
42  	// is not appended if it contains invalid characters.
43  	preRelease := normalizeVerString(appPreRelease)
44  	if preRelease != "" {
45  		version = fmt.Sprintf("%s-%s", version, preRelease)
46  	}
47  
48  	// Append build metadata if there is any.  The plus called for
49  	// by the semantic versioning spec is automatically appended and should
50  	// not be contained in the build metadata string.  The build metadata
51  	// string is not appended if it contains invalid characters.
52  	build := normalizeVerString(appBuild)
53  	if build != "" {
54  		version = fmt.Sprintf("%s+%s", version, build)
55  	}
56  
57  	return version
58  }
59  
60  // normalizeVerString returns the passed string stripped of all characters which
61  // are not valid according to the semantic versioning guidelines for pre-release
62  // version and build metadata strings.  In particular they MUST only contain
63  // characters in semanticAlphabet.
64  func normalizeVerString(str string) string {
65  	var result bytes.Buffer
66  	for _, r := range str {
67  		if strings.ContainsRune(semanticAlphabet, r) {
68  			// Ignoring the error here since it can only fail if
69  			// the the system is out of memory and there are much
70  			// bigger issues at that point.
71  			_, _ = result.WriteRune(r)
72  		}
73  	}
74  	return result.String()
75  }