func main() {
parser := args.NewParser(args.Name("http-client"),
args.Desc("Example http client client"))
parser.AddOption("--verbose").Alias("-v").Count().
Help("Be verbose")
parser.AddOption("--endpoint").Default("http://localhost:1234").Env("API_ENDPOINT").
Help("The HTTP endpoint our client will talk too")
parser.AddCommand("super-chickens", func(subParser *args.ArgParser, data interface{}) int {
subParser.AddCommand("create", createChickens)
subParser.AddCommand("list", listChickens)
subParser.AddCommand("delete", deleteChickens)
// Apply our super metadata =)
shared := data.(*SharedStruct)
shared.Metadata = "super"
// Run the sub-commands
retCode, err := subParser.ParseAndRun(nil, data)
if err != nil {
fmt.Println(err.Error())
return 1
}
return retCode
})
// Add our non super chicken actions
parser.AddCommand("create", createChickens)
parser.AddCommand("list", listChickens)
parser.AddCommand("delete", deleteChickens)
// Parse the command line
opts, err := parser.ParseArgs(nil)
if err != nil {
fmt.Fprintln(os.Stderr, err.Error())
os.Exit(1)
}
// Build our url from what the user passed in
parts, err := url.Parse(opts.String("endpoint"))
if err != nil {
fmt.Fprint(os.Stderr, "url endpoint '%s' is invalid", opts.String("endpoint"), err.Error())
os.Exit(1)
}
// This is a shows how you can pass in arbitrary struct
// data to your sub-commands allows you to share data and resources
// with sub-commands with out resorting to global variables
super := &SharedStruct{Metadata: "", Url: parts}
// Run the command chosen by the user
retCode, err := parser.RunCommand(super)
if err != nil {
fmt.Fprintln(os.Stderr, err.Error())
os.Exit(1)
}
os.Exit(retCode)
}
func main() {
var conf Config
// Create the parser with program name 'example'
// and environment variables prefixed with APP_
parser := args.NewParser(args.Name("demo"), args.EnvPrefix("APP_"),
args.Desc("This is a demo app to showcase some features of args"))
// Store Integers directly into a struct with a default value
parser.AddOption("--power-level").Alias("-p").StoreInt(&conf.PowerLevel).
Env("POWER_LEVEL").Default("10000").Help("set our power level")
// Command line options can begin with -name, --name or even ++name
// Most non word characters are supported
parser.AddOption("++config-file").Alias("+c").IsString().
Default("/path/to/config").Help("path to config file")
// Use the args.Env() function to define an environment variable
// NOTE: Since the parser was passed args.EnvPrefix("APP_") the actual
// environment variable name is 'APP_MESSAGE'
parser.AddOption("--message").Alias("-m").StoreStr(&conf.Message).
Env("MESSAGE").Default("over-ten-thousand").Help("send a message")
// Pass a comma separated list of strings and get a []string slice
parser.AddOption("--slice").Alias("-s").StoreStringSlice(&conf.StringSlice).Env("LIST").
Default("one,two,three").Help("list of messages")
// Count the number of times an option is seen
parser.AddOption("--verbose").Alias("-v").Count().StoreInt(&conf.Verbose).Help("be verbose")
// Set bool to true if the option is present on the command line
parser.AddOption("--debug").Alias("-d").IsTrue().Help("turn on Debug")
// Specify the type of the arg with IsInt(), IsString(), IsBool() or IsTrue()
parser.AddOption("--help").Alias("-h").IsTrue().Help("show this help message")
// Add Required arguments
parser.AddArgument("the-question").Required().
StoreStr(&conf.TheQuestion).Help("Before you have an answer")
// Add Optional arguments
parser.AddArgument("the-answer").IsInt().Default("42").
StoreInt(&conf.TheAnswer).Help("It must be 42")
// 'Conf' options are not set via the command line but can be set
// via a config file or an environment variable
parser.AddConfig("twelve-factor").Env("TWELVE_FACTOR").Help("Demo of config options")
// Define a 'database' subgroup
db := parser.InGroup("database")
// Add command line options to the subgroup
db.AddOption("--host").Alias("-dH").StoreStr(&conf.DbHost).
Default("localhost").Help("database hostname")
// Add subgroup specific config. 'Conf' options are not set via the
// command line but can be set via a config file or anything that calls parser.Apply()
db.AddConfig("debug").IsTrue().Help("enable database debug")
// 'Conf' option names are not allowed to start with a non word character like
// '--' or '++' so they can not be confused with command line options
db.AddConfig("database").IsString().Default("myDatabase").Help("name of database to use")
// If no type is specified, defaults to 'IsString'
db.AddConfig("user").Help("database user")
db.AddConfig("pass").Help("database password")
// Pass our own argument list, or nil to parse os.Args[]
opt := parser.ParseArgsSimple(nil)
// NOTE: ParseArgsSimple() is just a convenience, you can call
// parser.ParseArgs(nil) directly and handle the errors
// yourself if you have more complicated use case
// Demo default variables in a struct
fmt.Printf("Power '%d'\n", conf.PowerLevel)
fmt.Printf("Message '%s'\n", conf.Message)
fmt.Printf("String Slice '%s'\n", conf.StringSlice)
fmt.Printf("DbHost '%s'\n", conf.DbHost)
fmt.Printf("TheAnswer '%d'\n", conf.TheAnswer)
fmt.Println("")
// If user asked for --help or there were no options
// passed and none where required
if opt.NoArgs() || opt.Bool("help") {
parser.PrintHelp()
os.Exit(-1)
}
fmt.Println("")
fmt.Println("==================")
fmt.Println(" Direct Cast")
fmt.Println("==================")
// Fetch values by using the Cast functions
fmt.Printf("Power '%d'\n", opt.Int("power-level"))
fmt.Printf("Message '%s'\n", opt.String("message"))
fmt.Printf("String Slice '%s'\n", opt.StringSlice("slice"))
fmt.Printf("Verbose '%d'\n", opt.Int("verbose"))
fmt.Printf("Debug '%t'\n", opt.Bool("debug"))
fmt.Printf("TheAnswer '%d'\n", opt.Int("the-answer"))
fmt.Printf("TheAnswer as String '%s'\n", opt.String("the-answer"))
fmt.Println("")
fmt.Println("==================")
fmt.Println(" Database Group")
fmt.Println("==================")
// Fetch Group values
dbAddOption := opt.Group("database")
fmt.Printf("CAST DB Host '%s'\n", dbAddOption.String("host"))
fmt.Printf("CAST DB Debug '%t'\n", dbAddOption.Bool("debug"))
fmt.Printf("CAST DB User '%s'\n", dbAddOption.String("user"))
fmt.Printf("CAST DB Pass '%s'\n", dbAddOption.String("pass"))
fmt.Println("")
iniFile := []byte(`
power-level=20000
message=OVER-TEN-THOUSAND!
slice=three,four,five,six
verbose=5
debug=true
[database]
debug=false
host=mysql.thrawn01.org
user=my-username
pass=my-password
`)
// Make configuration simple by reading arguments from an INI file
opts, err := parser.FromINI(iniFile)
if err != nil {
fmt.Println(err.Error())
os.Exit(-1)
}
fmt.Println("")
fmt.Println("==================")
fmt.Println("From INI file")
fmt.Println("==================")
// Values from the config file are used only if the argument is not present
// on the commandline
fmt.Printf("INI Power '%d'\n", conf.PowerLevel)
fmt.Printf("INI Message '%s'\n", conf.Message)
fmt.Printf("INI Slice '%s'\n", conf.StringSlice)
fmt.Printf("INI Verbose '%d'\n", conf.Verbose)
fmt.Printf("INI Debug '%t'\n", opts.Bool("debug"))
fmt.Println("")
// Create an Options object from a map
opts = parser.NewOptionsFromMap(
map[string]interface{}{
"int": 1,
"bool": true,
"string": "one",
"endpoints": map[string]interface{}{
"endpoint1": "host1",
"endpoint2": "host2",
"endpoint3": "host3",
},
"deeply": map[string]interface{}{
"nested": map[string]interface{}{
"thing": "foo",
},
"foo": "bar",
},
},
)
// Small demo of how Group() works with options
opts.String("string") // == "one"
opts.Group("endpoints") // == *args.Options
opts.Group("endpoints").String("endpoint1") // == "host1"
opts.Group("endpoints").ToMap() // map[string]interface{} {"endpoint1": "host1", ...}
opts.StringMap("endpoints") // map[string]string {"endpoint1": "host1", ...}
opts.KeySlice("endpoints") // [ "endpoint1", "endpoint2", ]
opts.StringSlice("endpoints") // [ "host1", "host2", "host3" ]
// Leaves the door open for IntSlice(), IntMap(), etc....
}
func main() {
parser := args.NewParser(args.Name("watch"))
parser.AddOption("--bind").Alias("-b").Default("localhost:8080").
Help("Interface to bind the server too")
parser.AddOption("--complex-example").Alias("-ce").IsBool().
Help("Run the more complex example")
parser.AddOption("--config-file").Alias("-c").
Help("The Config file to load and watch our config from")
// Add a connection string to the database group
parser.AddOption("--connection-string").InGroup("database").Alias("-cS").
Default("mysql://username@hostname:MyDB").
Help("Connection string used to connect to the database")
// Store the password in the config and not passed via the command line
parser.AddConfig("password").InGroup("database").Help("database password")
// Specify a config file version, when this version number is updated, the user is signaling to the application
// that all edits are complete and the application can reload the config
parser.AddConfig("version").IsInt().Default("0").Help("config file version")
appConf, err := parser.ParseArgs(nil)
if err != nil {
fmt.Println(err.Error())
os.Exit(-1)
}
// Simple handler that prints out our config information
http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
conf := appConf.GetOpts()
db := conf.Group("database")
payload, err := json.Marshal(map[string]string{
"bind": conf.String("bind"),
"mysql": db.String("connection-string"),
"password": conf.Group("database").String("password"),
})
if err != nil {
fmt.Println("error:", err)
}
w.Header().Set("Content-Type", "application/json")
w.Write(payload)
})
var cancelWatch args.WatchCancelFunc
if appConf.Bool("complex-example") {
cancelWatch = complex(parser)
} else {
cancelWatch = simple(parser)
}
// Shut down the watcher when done
defer cancelWatch()
// Listen and serve requests
log.Printf("Listening for requests on %s", appConf.String("bind"))
err = http.ListenAndServe(appConf.String("bind"), nil)
if err != nil {
log.Println(err)
os.Exit(-1)
}
}
func main() {
var conf Config
// Create the parser
parser := args.Parser(args.Name("example"))
// Store Integers directly into a struct with a default value
parser.Opt("--power-level", args.Alias("-p"), args.StoreInt(&conf.PowerLevel),
args.Env("POWER_LEVEL"), args.Default("10000"), args.Help("set our power level"))
// Options can begin with -name, --name or even ++name. Most alpha non word character are supported
parser.Opt("++power", args.Alias("+p"), args.IsString(), args.Default("11,000"),
args.Help("prefix demo"))
// Use the args.Env() function to define an environment variable
parser.Opt("--message", args.Alias("-m"), args.StoreStr(&conf.Message),
args.Env("MESSAGE"), args.Default("over-ten-thousand"), args.Help("send a message"))
// Pass a comma seperated list of strings and get a []string
parser.Opt("--slice", args.Alias("-s"), args.StoreSlice(&conf.Slice),
args.Env("LIST"), args.Default("one,two,three"), args.Help("list of messages"))
// Count the number of times an argument is seen
parser.Opt("--verbose", args.Alias("-v"), args.Count(), args.StoreInt(&conf.Verbose),
args.Help("be verbose"))
// Set bool to true if the argument is present on the command line
parser.Opt("--debug", args.Alias("-d"), args.IsTrue(), args.Help("turn on Debug"))
// Specify the type of the arg with IsInt(), IsString(), IsBool() or IsTrue()
parser.Opt("--help", args.Alias("-h"), args.IsTrue(), args.Help("show this help message"))
// Pass our own argument list, or nil to parse os.Args[]
opt, err := parser.ParseArgs(nil)
if err != nil {
fmt.Println(err.Error())
os.Exit(-1)
}
// Fetch values by using the Cast functions
fmt.Printf("CAST Power '%d'\n", opt.Int("power-level"))
fmt.Printf("CAST Message '%s'\n", opt.String("message"))
fmt.Printf("CAST Slice '%s'\n", opt.Slice("slice"))
fmt.Printf("CAST Verbose '%d'\n", opt.Int("verbose"))
fmt.Printf("CAST Debug '%t'\n", opt.Bool("debug"))
fmt.Println("")
// Values can also be stored in a struct
fmt.Printf("STRUCT Power '%d'\n", conf.PowerLevel)
fmt.Printf("STRUCT Message '%s'\n", conf.Message)
fmt.Printf("STRUCT Slice '%s'\n", conf.Slice)
fmt.Printf("STRUCT Verbose '%d'\n", conf.Verbose)
fmt.Printf("STRUCT Debug '%t'\n", opt.Bool("debug"))
fmt.Println("")
iniFile := []byte(`
power-level=20000
message=OVER-THEN-THOUSAND!
slice=three,four,five,six
verbose=5
debug=true
`)
// Make configuration simply by reading arguments from an INI file
opt, err = parser.ParseIni(iniFile)
if err != nil {
fmt.Println(err.Error())
os.Exit(-1)
}
// Values from the config file are used only if the argument is not present
// on the commandline
fmt.Printf("INI Power '%d'\n", conf.PowerLevel)
fmt.Printf("INI Message '%s'\n", conf.Message)
fmt.Printf("INI Slice '%s'\n", conf.Slice)
fmt.Printf("INI Verbose '%d'\n", conf.Verbose)
fmt.Printf("INI Debug '%t'\n", opt.Bool("debug"))
fmt.Println("")
// If user asked for --help or there were no options passed
if opt.NoArgs() || opt.Bool("help") {
parser.PrintHelp()
os.Exit(-1)
}
}
parser := args.NewParser(args.WrapLen(80))
parser.AddOption("--power-level").Alias("-p").Help("Specify our power level")
parser.AddOption("--cat-level").
Alias("-c").
Help(`Lorem ipsum dolor sit amet, consectetur
mollit anim id est laborum.`)
msg := parser.GenerateHelpSection(args.IsOption)
Expect(msg).To(Equal(" -p, --power-level Specify our power level" +
"\n -c, --cat-level Lorem ipsum dolor sit amet, consecteturmollit anim id est" +
"\n laborum.\n"))
})
})
Describe("ArgParser.GenerateHelp()", func() {
It("Should generate help messages given a set of rules", func() {
parser := args.NewParser(args.EnvPrefix("APP_"), args.Desc("Small Description"),
args.Name("dragon-ball"), args.WrapLen(80))
parser.AddOption("--environ").Default("1").Alias("-e").Env("ENV").Help("Default thing")
parser.AddOption("--default").Default("0").Alias("-d").Help("Default thing")
parser.AddOption("--power-level").Alias("-p").Help("Specify our power level")
parser.AddOption("--cat-level").Alias("-c").Help(`Lorem ipsum dolor sit amet, consectetur
adipiscing elit, sed do eiusmod tempor incididunt ut labore et
mollit anim id est laborum.`)
msg := parser.GenerateHelp()
Expect(msg).To(ContainSubstring("Usage: dragon-ball [OPTIONS]"))
Expect(msg).To(ContainSubstring("-e, --environ Default thing (Default=1, Env=APP_ENV)"))
Expect(msg).To(ContainSubstring("-d, --default Default thing (Default=0)"))
Expect(msg).To(ContainSubstring("-p, --power-level Specify our power level"))
Expect(msg).To(ContainSubstring("Small Description"))
})
It("Should generate formated description if flag is set", func() {
desc := `
