cli

func ContextWithOptions ¶

func ContextWithOptions(ctx context.Context, fs *FlagSet) context.Context

ContextWithOptions iterates over the options in fs and returns a context with the options defined as values.

Options parsed are propagated to sub-command CLI via context.Context and can be retrieved by using OptionFromContext.

func Exit ¶

func Exit(r CLI, code int)

Exit prints r's usage and exits the program exit code.

func OptionFromContext ¶

func OptionFromContext(ctx context.Context, name string) (
	v interface{}, ok bool,
)

OptionFromContext attempts to retrieve the value of an flag named `name` from this context.

func Parse ¶

func Parse(fs *FlagSet, expectedArgs int, args []string) (
	actualArgs []string, rest []string, err error,
)

Parse parses all flags in args and returns the remaining arguments as defined by expectedArgs. Note that options are expected to be passed first, then arguments: [options] <arg1> <arg2> ...

Example:

  var myBoolOpt
  fs := NewFlagSet("ie", []string{"my-mandatory-arg"})
  fs.BoolVar(&myBoolOpt, "bool-opt", false, "bool opt flag")

	 fs.Parse([]string{"-bool-opt"}) // returns nil, ErrInvalidArgs
	 fs.Parse([]string{"my-value"}) // returns []string{"my-value"}, nil
	 fs.Parse([]string{"-bool-opt", "my-value"}) // returns []string{"my-value"}, nil
	 fs.Parse([]string{"-bool-opt", "my-value", "other-values"}) // returns []string{"my-value"}, nil

Note that ErrHelp is returned if -h or --help flags are in args.

func ParseAndRunCommand ¶

func ParseAndRunCommand(
	ctx context.Context, c CLI, fs *FlagSet, cmds map[string]CLI, args []string,
) error

ParseAndRunCommand is a helper to run CLI implementations that expect no arguments and simply run a sub-command CLI.

Options parsed are propagated to sub-command CLI via context.Context and can be retrieved by using OptionFromContext.

func ParseUsage ¶

func ParseUsage(cli CLI, fs *FlagSet, expectedArgs int, args []string) (
	rargs, rest []string, ok bool, err error,
)

ParseUsage calls Parse and handles ErrHelp by returning false. If flags are parsed with no errors and usage flag is not passed, then this function returns true.

func Run ¶

func Run(ctx context.Context, cli CLI) error

Run runs cli with os.Args

func RunCommand ¶

func RunCommand(ctx context.Context, args []string, cmds map[string]CLI) error

RunCommand is a helper that attempts to find and run the next command in cmds.

func Usage ¶

func Usage(cli CLI)

Usage is the function called when an error occurs while parsing a CLI's arguments or when -h flag is passed.

func UsageError ¶

func UsageError(cli CLI, err error)

UsageError prints err and the cli Usage.