github.com/bigcommerce/nomad@v0.9.3-bc/drivers/java/utils.go (about) 1 package java 2 3 import ( 4 "bytes" 5 "fmt" 6 "os/exec" 7 "regexp" 8 "strings" 9 ) 10 11 var javaVersionCommand = []string{"java", "-version"} 12 13 func javaVersionInfo() (version, runtime, vm string, err error) { 14 var out bytes.Buffer 15 16 cmd := exec.Command(javaVersionCommand[0], javaVersionCommand[1:]...) 17 cmd.Stdout = &out 18 cmd.Stderr = &out 19 err = cmd.Run() 20 if err != nil { 21 err = fmt.Errorf("failed to check java version: %v", err) 22 return 23 } 24 25 version, runtime, vm = parseJavaVersionOutput(out.String()) 26 return 27 } 28 29 func parseJavaVersionOutput(infoString string) (version, runtime, vm string) { 30 infoString = strings.TrimSpace(infoString) 31 32 lines := strings.Split(infoString, "\n") 33 if strings.Contains(lines[0], "Picked up _JAVA_OPTIONS") { 34 lines = lines[1:] 35 } 36 37 if len(lines) < 3 { 38 // unexpected output format, don't attempt to parse output for version 39 return "", "", "" 40 } 41 42 versionString := strings.TrimSpace(lines[0]) 43 44 re := regexp.MustCompile(`version "([^"]*)"`) 45 if match := re.FindStringSubmatch(lines[0]); len(match) == 2 { 46 versionString = match[1] 47 } 48 49 return versionString, strings.TrimSpace(lines[1]), strings.TrimSpace(lines[2]) 50 }