github.com/bhameyie/otto@v0.2.1-0.20160406174117-16052efa52ec/command/version.go (about) 1 package command 2 3 import ( 4 "bytes" 5 "fmt" 6 ) 7 8 // VersionCommand is a Command implementation prints the version. 9 type VersionCommand struct { 10 Meta 11 12 Revision string 13 Version string 14 VersionPrerelease string 15 CheckFunc VersionCheckFunc 16 } 17 18 // VersionCheckFunc is the callback called by the Version command to 19 // check if there is a new version of Otto. 20 type VersionCheckFunc func() (VersionCheckInfo, error) 21 22 // VersionCheckInfo is the return value for the VersionCheckFunc callback 23 // and tells the Version command information about the latest version 24 // of Otto. 25 type VersionCheckInfo struct { 26 Outdated bool 27 Latest string 28 Alerts []string 29 } 30 31 func (c *VersionCommand) Help() string { 32 return "" 33 } 34 35 func (c *VersionCommand) Run(args []string) int { 36 var versionString bytes.Buffer 37 38 fmt.Fprintf(&versionString, "Otto v%s", c.Version) 39 if c.VersionPrerelease != "" { 40 fmt.Fprintf(&versionString, "-%s", c.VersionPrerelease) 41 42 if c.Revision != "" { 43 fmt.Fprintf(&versionString, " (%s)", c.Revision) 44 } 45 } 46 47 c.Ui.Output(versionString.String()) 48 49 // If we have a version check function, then let's check for 50 // the latest version as well. 51 if c.CheckFunc != nil { 52 // Separate the prior output with a newline 53 c.Ui.Output("") 54 55 // Check the latest version 56 info, err := c.CheckFunc() 57 if err != nil { 58 c.Ui.Error(fmt.Sprintf( 59 "Error checking latest version: %s", err)) 60 } 61 if info.Outdated { 62 c.Ui.Output(fmt.Sprintf( 63 "Your version of Otto is out of date! The latest version\n"+ 64 "is %s. You can update by downloading from www.ottoproject.io", 65 info.Latest)) 66 } 67 } 68 69 return 0 70 } 71 72 func (c *VersionCommand) Synopsis() string { 73 return "Prints the Otto version" 74 }