cloudflared-mirror/vendor/gopkg.in/urfave/cli.v2/context.go

237 lines
5.2 KiB
Go

package cli
import (
"errors"
"flag"
"os"
"reflect"
"strings"
)
// Context is a type that is passed through to
// each Handler action in a cli application. Context
// can be used to retrieve context-specific args and
// parsed command-line options.
type Context struct {
App *App
Command *Command
shellComplete bool
flagSet *flag.FlagSet
parentContext *Context
}
// NewContext creates a new context. For use in when invoking an App or Command action.
func NewContext(app *App, set *flag.FlagSet, parentCtx *Context) *Context {
c := &Context{App: app, flagSet: set, parentContext: parentCtx}
if parentCtx != nil {
c.shellComplete = parentCtx.shellComplete
}
return c
}
// NumFlags returns the number of flags set
func (c *Context) NumFlags() int {
return c.flagSet.NFlag()
}
// Set sets a context flag to a value.
func (c *Context) Set(name, value string) error {
return c.flagSet.Set(name, value)
}
// IsSet determines if the flag was actually set
func (c *Context) IsSet(name string) bool {
if fs := lookupFlagSet(name, c); fs != nil {
isSet := false
fs.Visit(func(f *flag.Flag) {
if f.Name == name {
isSet = true
}
})
if isSet {
return true
}
}
// XXX hack to support IsSet for flags with EnvVar
//
// There isn't an easy way to do this with the current implementation since
// whether a flag was set via an environment variable is very difficult to
// determine here. Instead, we intend to introduce a backwards incompatible
// change in version 2 to add `IsSet` to the Flag interface to push the
// responsibility closer to where the information required to determine
// whether a flag is set by non-standard means such as environment
// variables is avaliable.
//
// See https://github.com/urfave/cli/issues/294 for additional discussion
f := lookupFlag(name, c)
if f == nil {
return false
}
val := reflect.ValueOf(f)
if val.Kind() == reflect.Ptr {
val = val.Elem()
}
envVarValues := val.FieldByName("EnvVars")
if !envVarValues.IsValid() {
return false
}
for _, envVar := range envVarValues.Interface().([]string) {
envVar = strings.TrimSpace(envVar)
if envVal := os.Getenv(envVar); envVal != "" {
return true
}
}
return false
}
// LocalFlagNames returns a slice of flag names used in this context.
func (c *Context) LocalFlagNames() []string {
names := []string{}
c.flagSet.Visit(makeFlagNameVisitor(&names))
return names
}
// FlagNames returns a slice of flag names used by the this context and all of
// its parent contexts.
func (c *Context) FlagNames() []string {
names := []string{}
for _, ctx := range c.Lineage() {
ctx.flagSet.Visit(makeFlagNameVisitor(&names))
}
return names
}
// Lineage returns *this* context and all of its ancestor contexts in order from
// child to parent
func (c *Context) Lineage() []*Context {
lineage := []*Context{}
for cur := c; cur != nil; cur = cur.parentContext {
lineage = append(lineage, cur)
}
return lineage
}
// value returns the value of the flag corresponding to `name`
func (c *Context) value(name string) interface{} {
return c.flagSet.Lookup(name).Value.(flag.Getter).Get()
}
// Args returns the command line arguments associated with the context.
func (c *Context) Args() Args {
ret := args(c.flagSet.Args())
return &ret
}
// NArg returns the number of the command line arguments.
func (c *Context) NArg() int {
return c.Args().Len()
}
func lookupFlag(name string, ctx *Context) Flag {
for _, c := range ctx.Lineage() {
if c.Command == nil {
continue
}
for _, f := range c.Command.Flags {
for _, n := range f.Names() {
if n == name {
return f
}
}
}
}
if ctx.App != nil {
for _, f := range ctx.App.Flags {
for _, n := range f.Names() {
if n == name {
return f
}
}
}
}
return nil
}
func lookupFlagSet(name string, ctx *Context) *flag.FlagSet {
for _, c := range ctx.Lineage() {
if f := c.flagSet.Lookup(name); f != nil {
return c.flagSet
}
}
return nil
}
func copyFlag(name string, ff *flag.Flag, set *flag.FlagSet) {
switch ff.Value.(type) {
case Serializeder:
set.Set(name, ff.Value.(Serializeder).Serialized())
default:
set.Set(name, ff.Value.String())
}
}
func normalizeFlags(flags []Flag, set *flag.FlagSet) error {
visited := make(map[string]bool)
set.Visit(func(f *flag.Flag) {
visited[f.Name] = true
})
for _, f := range flags {
parts := f.Names()
if len(parts) == 1 {
continue
}
var ff *flag.Flag
for _, name := range parts {
name = strings.Trim(name, " ")
if visited[name] {
if ff != nil {
return errors.New("Cannot use two forms of the same flag: " + name + " " + ff.Name)
}
ff = set.Lookup(name)
}
}
if ff == nil {
continue
}
for _, name := range parts {
name = strings.Trim(name, " ")
if !visited[name] {
copyFlag(name, ff, set)
}
}
}
return nil
}
func makeFlagNameVisitor(names *[]string) func(*flag.Flag) {
return func(f *flag.Flag) {
nameParts := strings.Split(f.Name, ",")
name := strings.TrimSpace(nameParts[0])
for _, part := range nameParts {
part = strings.TrimSpace(part)
if len(part) > len(name) {
name = part
}
}
if name != "" {
(*names) = append(*names, name)
}
}
}