package cli import ( "errors" "flag" "reflect" "strings" "syscall" ) // 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 setFlags map[string]bool 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) } // GlobalSet sets a context flag to a value on the global flagset func (c *Context) GlobalSet(name, value string) error { return globalContext(c).flagSet.Set(name, value) } // IsSet determines if the flag was actually set func (c *Context) IsSet(name string) bool { if c.setFlags == nil { c.setFlags = make(map[string]bool) c.flagSet.Visit(func(f *flag.Flag) { c.setFlags[f.Name] = true }) c.flagSet.VisitAll(func(f *flag.Flag) { if _, ok := c.setFlags[f.Name]; ok { return } c.setFlags[f.Name] = false }) // 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 flags := c.Command.Flags if c.Command.Name == "" { // cannot == Command{} since it contains slice types if c.App != nil { flags = c.App.Flags } } for _, f := range flags { eachName(f.GetName(), func(name string) { if isSet, ok := c.setFlags[name]; isSet || !ok { return } val := reflect.ValueOf(f) if val.Kind() == reflect.Ptr { val = val.Elem() } envVarValue := val.FieldByName("EnvVar") if !envVarValue.IsValid() { return } eachName(envVarValue.String(), func(envVar string) { envVar = strings.TrimSpace(envVar) if _, ok := syscall.Getenv(envVar); ok { c.setFlags[name] = true return } }) }) } } return c.setFlags[name] } // GlobalIsSet determines if the global flag was actually set func (c *Context) GlobalIsSet(name string) bool { ctx := c if ctx.parentContext != nil { ctx = ctx.parentContext } for ; ctx != nil; ctx = ctx.parentContext { if ctx.IsSet(name) { return true } } return false } // FlagNames returns a slice of flag names used in this context. func (c *Context) FlagNames() (names []string) { for _, flag := range c.Command.Flags { name := strings.Split(flag.GetName(), ",")[0] if name == "help" { continue } names = append(names, name) } return } // GlobalFlagNames returns a slice of global flag names used by the app. func (c *Context) GlobalFlagNames() (names []string) { for _, flag := range c.App.Flags { name := strings.Split(flag.GetName(), ",")[0] if name == "help" || name == "version" { continue } names = append(names, name) } return } // Parent returns the parent context, if any func (c *Context) Parent() *Context { return c.parentContext } // value returns the value of the flag coressponding to `name` func (c *Context) value(name string) interface{} { return c.flagSet.Lookup(name).Value.(flag.Getter).Get() } // Args contains apps console arguments type Args []string // Args returns the command line arguments associated with the context. func (c *Context) Args() Args { args := Args(c.flagSet.Args()) return args } // NArg returns the number of the command line arguments. func (c *Context) NArg() int { return len(c.Args()) } // Get returns the nth argument, or else a blank string func (a Args) Get(n int) string { if len(a) > n { return a[n] } return "" } // First returns the first argument, or else a blank string func (a Args) First() string { return a.Get(0) } // Last - Return the last argument, or else a blank string func (a Args) Last() string { return a.Get(len(a) - 1) } // Head - Return the rest of the arguments (not the last one) // or else an empty string slice func (a Args) Head() Args { if len(a) == 1 { return a } return []string(a)[:len(a)-1] } // Tail returns the rest of the arguments (not the first one) // or else an empty string slice func (a Args) Tail() Args { if len(a) >= 2 { return []string(a)[1:] } return []string{} } // Present checks if there are any arguments present func (a Args) Present() bool { return len(a) != 0 } // Swap swaps arguments at the given indexes func (a Args) Swap(from, to int) error { if from >= len(a) || to >= len(a) { return errors.New("index out of range") } a[from], a[to] = a[to], a[from] return nil } func globalContext(ctx *Context) *Context { if ctx == nil { return nil } for { if ctx.parentContext == nil { return ctx } ctx = ctx.parentContext } } func lookupGlobalFlagSet(name string, ctx *Context) *flag.FlagSet { if ctx.parentContext != nil { ctx = ctx.parentContext } for ; ctx != nil; ctx = ctx.parentContext { if f := ctx.flagSet.Lookup(name); f != nil { return ctx.flagSet } } return nil } func copyFlag(name string, ff *flag.Flag, set *flag.FlagSet) { switch ff.Value.(type) { case *StringSlice: 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 := strings.Split(f.GetName(), ",") 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 }