Describe("args.ParseArgs(nil)", func() {
parser := args.Parser()
It("Should return error if Opt() was never called", func() {
_, err := parser.ParseArgs(nil)
Expect(err).ToNot(BeNil())
Expect(err.Error()).To(Equal("Must create some options to match with args.Opt() before calling arg.ParseArgs()"))
})
})
Describe("args.Opt()", func() {
cmdLine := []string{"--one", "-two", "++three", "+four", "--power-level"}
It("Should create optional rule --one", func() {
parser := args.Parser()
parser.Opt("--one", args.Count())
rule := parser.GetRules()[0]
Expect(rule.Name).To(Equal("one"))
Expect(rule.IsPos).To(Equal(0))
})
It("Should create optional rule ++one", func() {
parser := args.Parser()
parser.Opt("++one", args.Count())
rule := parser.GetRules()[0]
Expect(rule.Name).To(Equal("one"))
Expect(rule.IsPos).To(Equal(0))
})
It("Should create optional rule -one", func() {
parser := args.Parser()
func main() {
var conf Config
//parser := args.Parser(args.WarnUnknownArgs(), args.UsageName("my-program"))
parser := args.Parser()
// Positional Argument, there can be more than one argument and the result will be an array
parser.Pos("count", args.Append(), args.IsInt(), args.Help("Count the numbers provided"))
// Optional Positional Argument, the order the positional arguments are
// defined is the order they are expected on the command line
parser.Pos("infile", args.Optional(), args.IsString(), args.Help("Output file, If none supplied reads from stdin"))
parser.Pos("outfile", args.Optional(), args.IsString(), args.Help("Input file, If none supplied writes to stdout"))
// Counts the number of instances a flag is seen and stores the count as an integer
parser.Opt("--verbose", args.Alias("-v"), args.Count(),
args.Help("Prints Stuff and things"))
// String with default option and Environment option (VarName defines the help message value name)
parser.Opt("--bind", args.Alias("-b"), args.IsString(), args.VarName("ADDRESS"), args.Default("localhost:8080"),
args.Env("BIND_ADDRESS"), args.Store(&conf.Bind), args.Help("The network interface to bind too"))
// Unusual option indicators
parser.Opt("++unusual", args.Alias("+u"), args.IsBool(), args.Default(false),
args.Help("Unusual option indicator"))
parser.Opt("-short", args.Alias("-s"), args.IsBool(), args.Default(false),
args.Help("Short option indicator"))
// Booleans
parser.Opt("--debug", args.Alias("-d"), args.IsBool(), args.Default(false),
args.Help("Turns on debug messages"))
// Append stores an array, and appends each argument value to the array. This allows an option to be specified multiple times.
parser.Opt("--endpoint", args.Alias("-e"), args.Append(), args.IsString(),
args.Default([]string{"http://google.com"}), args.Help("The endpoints to proxy for"))
// Take an option and split the arguments IE: --terms one,two,three
parser.Opt("--terms", args.Alias("-t"), args.Array(), args.IsString(),
args.Default([]string{"foo", "bar"}), args.Help("The terms used to search google with"))
// Give the user choices
parser.Opt("--choice", args.Alias("-c"), args.Choice(), args.IsInt(),
args.Default([]int{1, 2, 3}), args.Help("You can only choose 1,2 or 3"))
// Give the option is required (Required options can not have defaults)
parser.Opt("--required", args.Alias("-r"), args.Required(), args.IsString(),
args.Help("This option is required"))
// Display Help
parser.Opt("--help", args.Alias("-h"), args.IsBool(), args.Help("Display this help message"))
//opts, err := parser.ParseArgs([]string{"-p", "-vvv"})
opts, err := parser.Parse()
if err != nil {
fmt.Println("-- %s", err.Error())
opts.PrintUsage()
os.Exit(-1)
}
// If user asked for --help or there were no options passed
if opts.NoArgs() && opts.Bool("help") {
opts.PrintHelp()
os.Exit(-1)
}
fmt.Printf("Bind Address from opts: %s", opts.String("bind"))
fmt.Printf("Bind Address from Config struct: %s", conf.Bind)
fmt.Printf("Verbose Count: %d", opts.Int("verbose"))
fmt.Printf("Debug Boolean: %b", opts.Bool("debug"))
for _, endpoint := range opts.Array("endpoint").([]string) {
fmt.Println("Endpoint: %s", endpoint)
}
// Parent that provides shared options
parent := args.Parser()
parent.Opt("verbose", args.Alias("-v"), args.Count(), args.Help("Be verbose"))
// Sub Parser, Any arguments past the positional arg 'sub1' will be considered by this sub
sub := parser.SubParser("volume")
// parser and will inherit all the opts from the parent parser
list := sub.SubParser("list", args.Inherit(parent))
list.Opt("filter", args.Alias("-f"), args.IsBool(), args.Help("Filter the list by this thingy"))
}
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)
}
}