package main import ( "flag" "fmt" "os" "strings" "text/template" ) var usagePrefix = ` warren is a tool for building, deploying and running multiple versions of a Go server Usage: warren command [args] ` var usageTmpl = template.Must(template.New("usage").Parse(` Commands:{{range .}} {{.Name | printf "%-10s"}} {{.Summary}}{{end}} `)) var commands = []*Command{ buildCmd, } func usage() { fmt.Print(usagePrefix) usageTmpl.Execute(os.Stdout, commands) } func main() { flag.Usage = usage flag.Parse() args := flag.Args() if len(args) == 0 || args[0] == "-h" { flag.Usage() return } var cmd *Command name := args[0] for _, c := range commands { if strings.HasPrefix(c.Name, name) { cmd = c break } } if cmd == nil { fmt.Printf("error: unknown command %q\n", name) flag.Usage() os.Exit(1) } cmd.Exec(args[1:]) }