engine

package
v0.0.12 Latest Latest
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 Go to latest Published: Jul 24, 2025 License: Apache-2.0 Imports: 17 Imported by: 0

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Index

Constants

This section is empty.

Variables

This section is empty.

Functions

func IsHelpRequested 

func IsHelpRequested(err error) bool

IsHelpRequested checks if the error is a HelpRequested sentinel.

func IsVersionRequested 

func IsVersionRequested(err error) bool

IsVersionRequested checks if the error is a VersionRequested sentinel

func RequestHelp 

func RequestHelp(msg string) error

RequestHelp returns an error with type HelpRequested and the given message.

func RequestVersion 

func RequestVersion(msg string) error

RequestVersion returns an error with type VersionRequested and the given message.

Types

type ErrorHandling 

type ErrorHandling int
const (
	// ContinueOnError will return an err from Parse() if an error is found
	ContinueOnError ErrorHandling = iota
	// ExitOnError will call os.Exit(2) if an error is found when parsing
	ExitOnError
	// PanicOnError will panic() if an error is found when parsing flags
	PanicOnError
)

type FlagPrintMode 

type FlagPrintMode int

FlagPrintMode defines how usage should be rendered. 

const (
	PrintShort FlagPrintMode = iota // Only short flags (e.g., -v)
	PrintLong                       // Only long flags (e.g., --verbose)
	PrintBoth                       // Combined short|long (e.g., -v|--verbose)
	PrintFlags                      // Just "Usage: [flags]"
	PrintNone                       // No usage tokens shown
)

type FlagSet 

type FlagSet struct {
	Usage func() // Usage is the customizable function for printing usage. Defaults to printing title, description, flags, and notes.
	// contains filtered or unexported fields
}

FlagSet manages the definition, parsing, and usage output of command-line flags.

func NewFlagSet 

func NewFlagSet(name string, errorHandling ErrorHandling) *FlagSet

NewFlagSet creates a new FlagSet with the given name and error handling policy.

func (*FlagSet) AddGroup 

func (f *FlagSet) AddGroup(name string, g *core.MutualGroup)

AddGroup manually adds a mutual group.

func (*FlagSet) Arg 

func (f *FlagSet) Arg(i int) (string, bool)

Arg returns the positional argument at index i.

func (*FlagSet) Args 

func (f *FlagSet) Args() []string

Args returns all remaining positional arguments.

func (*FlagSet) AttachToGroup 

func (f *FlagSet) AttachToGroup(bf *core.BaseFlag, group string)

AttachToGroup connects a flag to a mutual exclusion group.

func (*FlagSet) Authors 

func (f *FlagSet) Authors(s string)

func (*FlagSet) Bool 

func (f *FlagSet) Bool(name string, def bool, usage string) *scalar.BoolFlag

func (*FlagSet) BoolVar 

func (f *FlagSet) BoolVar(ptr *bool, name string, def bool, usage string) *scalar.BoolFlag

func (*FlagSet) BytesSliceVar 

func (f *FlagSet) BytesSliceVar(ptr *[]uint64, name string, def []uint64, usage string) *slice.SliceFlag[uint64]

BytesVar defines a uint64 “bytes” flag (e.g. "1GB", "512M").

func (*FlagSet) BytesVar 

func (f *FlagSet) BytesVar(ptr *uint64, name string, def uint64, usage string) *scalar.ScalarFlag[uint64]

BytesVar defines a uint64 “bytes” flag (e.g. "1GB", "512M").

func (*FlagSet) CounterVar 

func (f *FlagSet) CounterVar(ptr *int, name string, def int, usage string) *scalar.CounterFlag

func (*FlagSet) DefaultDelimiter 

func (f *FlagSet) DefaultDelimiter() string

DefaultDelimiter returns the current default delimiter.

func (*FlagSet) Description 

func (f *FlagSet) Description(s string)

Description sets the prolog text shown above the flags.

func (*FlagSet) DescriptionIndent 

func (f *FlagSet) DescriptionIndent(indent int)

DescriptionIndent sets the number of spaces before descriptions.

func (*FlagSet) DescriptionMaxLen 

func (f *FlagSet) DescriptionMaxLen(line int)

DescriptionMaxLen sets the maximum line width for wrapped descriptions.

func (*FlagSet) DisableHelp 

func (f *FlagSet) DisableHelp()

DisableHelp disables the automatic --help flag.

func (*FlagSet) DisableVersion 

func (f *FlagSet) DisableVersion()

DisableVersion disables the automatic --version flag.

func (*FlagSet) DurationSliceVar 

func (f *FlagSet) DurationSliceVar(ptr *[]time.Duration, name string, def []time.Duration, usage string) *slice.SliceFlag[time.Duration]

DurationVar defines a time.Duration flag.

func (*FlagSet) DurationVar 

func (f *FlagSet) DurationVar(ptr *time.Duration, name string, def time.Duration, usage string) *scalar.ScalarFlag[time.Duration]

DurationVar defines a time.Duration flag.

func (*FlagSet) DynamicGroup 

func (f *FlagSet) DynamicGroup(name string) *dynamic.Group

DynamicGroup creates a new dynamic group with the given prefix.

func (*FlagSet) DynamicGroups added in v0.0.9 

func (f *FlagSet) DynamicGroups() []*dynamic.Group

func (*FlagSet) EnvPrefix 

func (f *FlagSet) EnvPrefix(prefix string)

EnvPrefix sets a prefix to be prepended to all environment variables.

func (*FlagSet) FileSliceVar 

func (f *FlagSet) FileSliceVar(ptr *[]*os.File, name string, def []*os.File, usage string) *slice.SliceFlag[*os.File]

FileVar defines an *os.File flag (opened for reading).

func (*FlagSet) FileVar 

func (f *FlagSet) FileVar(ptr **os.File, name string, def *os.File, usage string) *scalar.ScalarFlag[*os.File]

FileVar defines an *os.File flag (opened for reading).

func (*FlagSet) Float32SliceVar 

func (f *FlagSet) Float32SliceVar(ptr *[]float32, name string, def []float32, usage string) *slice.SliceFlag[float32]

Float32Var defines a float32 flag.

func (*FlagSet) Float32Var 

func (f *FlagSet) Float32Var(ptr *float32, name string, def float32, usage string) *scalar.ScalarFlag[float32]

Float32Var defines a float32 flag.

func (*FlagSet) Float64SliceVar 

func (f *FlagSet) Float64SliceVar(ptr *[]float64, name string, def []float64, usage string) *slice.SliceFlag[float64]

Float64Var defines a float64 flag.

func (*FlagSet) Float64Var 

func (f *FlagSet) Float64Var(ptr *float64, name string, def float64, usage string) *scalar.ScalarFlag[float64]

Float64Var defines a float64 flag.

func (*FlagSet) GetGroup 

func (f *FlagSet) GetGroup(name string) *core.MutualGroup

GetGroup returns a mutual exclusion group by name (creating it if necessary).

func (*FlagSet) Globaldelimiter 

func (f *FlagSet) Globaldelimiter(s string)

Globaldelimiter sets the delimiter used for slice flags.

func (*FlagSet) Groups 

func (f *FlagSet) Groups() []*core.MutualGroup

Groups returns all mutual exclusion groups.

func (*FlagSet) HideEnvs 

func (f *FlagSet) HideEnvs()

func (*FlagSet) IPSliceVar 

func (f *FlagSet) IPSliceVar(ptr *[]net.IP, name string, def []net.IP, usage string) *slice.SliceFlag[net.IP]

IPVar defines a net.IP flag.

func (*FlagSet) IPVar 

func (f *FlagSet) IPVar(ptr *net.IP, name string, def net.IP, usage string) *scalar.ScalarFlag[net.IP]

IPVar defines a net.IP flag.

func (*FlagSet) IPv4MaskSliceVar 

func (f *FlagSet) IPv4MaskSliceVar(ptr *[]net.IPMask, name string, def []net.IPMask, usage string) *slice.SliceFlag[net.IPMask]

IPv4MaskVar defines a net.IPMask flag.

func (*FlagSet) IPv4MaskVar 

func (f *FlagSet) IPv4MaskVar(ptr *net.IPMask, name string, def net.IPMask, usage string) *scalar.ScalarFlag[net.IPMask]

IPv4MaskVar defines a net.IPMask flag.

func (*FlagSet) IgnoreInvalidEnv 

func (f *FlagSet) IgnoreInvalidEnv(enable bool)

IgnoreInvalidEnv controls whether unknown environment values cause errors.

func (*FlagSet) IntSliceVar 

func (f *FlagSet) IntSliceVar(ptr *[]int, name string, def []int, usage string) *slice.SliceFlag[int]

IntVar defines an int flag.

func (*FlagSet) IntVar 

func (f *FlagSet) IntVar(ptr *int, name string, def int, usage string) *scalar.ScalarFlag[int]

IntVar defines an int flag.

func (*FlagSet) Name 

func (f *FlagSet) Name() string

Name returns the name of the application.

func (*FlagSet) Note 

func (f *FlagSet) Note(s string)

Note sets the epilog text shown below the flags.

func (*FlagSet) Output 

func (f *FlagSet) Output() io.Writer

Output returns the configured help writer.

func (*FlagSet) Parse 

func (f *FlagSet) Parse(args []string) error

Parse parses CLI arguments, env vars, built-in help/version, and validations.

func (*FlagSet) PrintAuthors 

func (f *FlagSet) PrintAuthors(w io.Writer)

PrintAuthors writes the usage authors heading.

func (*FlagSet) PrintDefaults 

func (f *FlagSet) PrintDefaults()

PrintDefaults prints all visible flags with their descriptions.

func (*FlagSet) PrintDescription 

func (f *FlagSet) PrintDescription(w io.Writer, width int)

PrintDescription renders the prolog text above flags.

func (*FlagSet) PrintNotes 

func (f *FlagSet) PrintNotes(w io.Writer, width int)

PrintNotes renders the epilog text below flags.

func (*FlagSet) PrintTitle 

func (f *FlagSet) PrintTitle(w io.Writer)

PrintTitle writes the usage title heading.

func (*FlagSet) PrintUsage 

func (f *FlagSet) PrintUsage(w io.Writer, mode FlagPrintMode)

PrintUsage prints a usage line including flags depending on mode.

func (*FlagSet) RegisterFlag 

func (f *FlagSet) RegisterFlag(name string, bf *core.BaseFlag)

RegisterFlag registers a static flag.

func (*FlagSet) RequirePositional 

func (f *FlagSet) RequirePositional(n int)

RequirePositional sets how many positional arguments are required.

func (*FlagSet) SetGetEnvFn 

func (f *FlagSet) SetGetEnvFn(fn func(string) string)

SetGetEnvFn sets a custom environment lookup function.

func (*FlagSet) SetOutput 

func (f *FlagSet) SetOutput(w io.Writer)

SetOutput sets the writer for help output.

func (*FlagSet) Sorted 

func (f *FlagSet) Sorted(enable bool)

Sorted enables or disables sorted help output.

func (*FlagSet) StringSliceVar 

func (f *FlagSet) StringSliceVar(ptr *[]string, name string, def []string, usage string) *slice.SliceFlag[string]

StringVar defines a string flag.

func (*FlagSet) StringVar 

func (f *FlagSet) StringVar(ptr *string, name string, def string, usage string) *scalar.ScalarFlag[string]

StringVar defines a string flag.

func (*FlagSet) TCPAddrSliceVar 

func (f *FlagSet) TCPAddrSliceVar(ptr *[]*net.TCPAddr, name string, def []*net.TCPAddr, usage string) *slice.SliceFlag[*net.TCPAddr]

TCPAddrVar defines a *net.TCPAddr flag.

func (*FlagSet) TCPAddrVar 

func (f *FlagSet) TCPAddrVar(ptr **net.TCPAddr, name string, def *net.TCPAddr, usage string) *scalar.ScalarFlag[*net.TCPAddr]

TCPAddrVar defines a *net.TCPAddr flag.

func (*FlagSet) TimeSliceVar 

func (f *FlagSet) TimeSliceVar(ptr *[]time.Time, name string, def []time.Time, usage string) *slice.SliceFlag[time.Time]

TimeVar defines a time.Time flag (parsed as RFC3339).

func (*FlagSet) TimeVar 

func (f *FlagSet) TimeVar(ptr *time.Time, name string, def time.Time, usage string) *scalar.ScalarFlag[time.Time]

TimeVar defines a time.Time flag (parsed as RFC3339).

func (*FlagSet) Title 

func (f *FlagSet) Title(s string)

Title sets the usage section title.

func (*FlagSet) URLSliceVar 

func (f *FlagSet) URLSliceVar(ptr *[]*url.URL, name string, def []*url.URL, usage string) *slice.SliceFlag[*url.URL]

URLVar defines a url.URL flag.

func (*FlagSet) URLVar 

func (f *FlagSet) URLVar(ptr **url.URL, name string, def *url.URL, usage string) *scalar.ScalarFlag[*url.URL]

URLVar defines a url.URL flag.

func (*FlagSet) Version 

func (f *FlagSet) Version(s string)

Version sets the version string to enable the --version flag.

type HelpRequested 

type HelpRequested struct {
	Message string // The full help message to show the user
}

HelpRequested is returned when the built-in help flag (-h or --help) is triggered.

func (*HelpRequested) Error 

func (e *HelpRequested) Error() string

Error returns the help message, satisfying the error interface.

type VersionRequested 

type VersionRequested struct {
	Version string // The version string to show the user
}

VersionRequested is returned when the built-in version flag (--version) is triggered.

func (*VersionRequested) Error 

func (e *VersionRequested) Error() string

Error returns the version string, satisfying the error interface.

Source Files

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