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package cli
import (
"errors"
"flag"
"strconv"
"strings"
"time"
)
// 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
flagSet *flag.FlagSet
setFlags map[string]bool
globalSetFlags map[string]bool
}
// Creates a new context. For use in when invoking an App or Command action.
func NewContext(app *App, set *flag.FlagSet, parentCtx *Context) *Context {
return &Context{App: app, flagSet: set, parentContext: parentCtx}
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}
// Looks up the value of a local int flag, returns 0 if no int flag exists
func (c *Context) Int(name string) int {
return lookupInt(name, c.flagSet)
}
// Looks up the value of a local time.Duration flag, returns 0 if no time.Duration flag exists
func (c *Context) Duration(name string) time.Duration {
return lookupDuration(name, c.flagSet)
}
// Looks up the value of a local float64 flag, returns 0 if no float64 flag exists
func (c *Context) Float64(name string) float64 {
return lookupFloat64(name, c.flagSet)
}
// Looks up the value of a local bool flag, returns false if no bool flag exists
func (c *Context) Bool(name string) bool {
return lookupBool(name, c.flagSet)
}
// Looks up the value of a local boolT flag, returns false if no bool flag exists
func (c *Context) BoolT(name string) bool {
return lookupBoolT(name, c.flagSet)
}
// Looks up the value of a local string flag, returns "" if no string flag exists
func (c *Context) String(name string) string {
return lookupString(name, c.flagSet)
}
// Looks up the value of a local string slice flag, returns nil if no string slice flag exists
func (c *Context) StringSlice(name string) []string {
return lookupStringSlice(name, c.flagSet)
}
// Looks up the value of a local int slice flag, returns nil if no int slice flag exists
func (c *Context) IntSlice(name string) []int {
return lookupIntSlice(name, c.flagSet)
}
// Looks up the value of a local generic flag, returns nil if no generic flag exists
func (c *Context) Generic(name string) interface{} {
return lookupGeneric(name, c.flagSet)
}
// Looks up the value of a global int flag, returns 0 if no int flag exists
func (c *Context) GlobalInt(name string) int {
if fs := lookupGlobalFlagSet(name, c); fs != nil {
return lookupInt(name, fs)
}
return 0
}
// Looks up the value of a global time.Duration flag, returns 0 if no time.Duration flag exists
func (c *Context) GlobalDuration(name string) time.Duration {
if fs := lookupGlobalFlagSet(name, c); fs != nil {
return lookupDuration(name, fs)
}
return 0
}
// Looks up the value of a global bool flag, returns false if no bool flag exists
func (c *Context) GlobalBool(name string) bool {
if fs := lookupGlobalFlagSet(name, c); fs != nil {
return lookupBool(name, fs)
}
return false
}
// Looks up the value of a global string flag, returns "" if no string flag exists
func (c *Context) GlobalString(name string) string {
if fs := lookupGlobalFlagSet(name, c); fs != nil {
return lookupString(name, fs)
}
return ""
}
// Looks up the value of a global string slice flag, returns nil if no string slice flag exists
func (c *Context) GlobalStringSlice(name string) []string {
if fs := lookupGlobalFlagSet(name, c); fs != nil {
return lookupStringSlice(name, fs)
}
return nil
}
// Looks up the value of a global int slice flag, returns nil if no int slice flag exists
func (c *Context) GlobalIntSlice(name string) []int {
if fs := lookupGlobalFlagSet(name, c); fs != nil {
return lookupIntSlice(name, fs)
}
return nil
}
// Looks up the value of a global generic flag, returns nil if no generic flag exists
func (c *Context) GlobalGeneric(name string) interface{} {
if fs := lookupGlobalFlagSet(name, c); fs != nil {
return lookupGeneric(name, fs)
}
return nil
}
// Returns the number of flags set
func (c *Context) NumFlags() int {
return c.flagSet.NFlag()
}
// 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
})
}
return c.setFlags[name] == true
}
// Determines if the global flag was actually set
func (c *Context) GlobalIsSet(name string) bool {
if c.globalSetFlags == nil {
c.globalSetFlags = make(map[string]bool)
ctx := c
if ctx.parentContext != nil {
ctx = ctx.parentContext
}
for ; ctx != nil && c.globalSetFlags[name] == false; ctx = ctx.parentContext {
ctx.flagSet.Visit(func(f *flag.Flag) {
c.globalSetFlags[f.Name] = true
})
}
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}
// 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
}
// 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
}
// Returns the parent context, if any
func (c *Context) Parent() *Context {
return c.parentContext
}
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type Args []string
// Returns the command line arguments associated with the context.
func (c *Context) Args() Args {
args := Args(c.flagSet.Args())
return args
}
// Returns the nth argument, or else a blank string
func (a Args) Get(n int) string {
if len(a) > n {
return a[n]
}
return ""
}
// Returns the first argument, or else a blank string
func (a Args) First() string {
return a.Get(0)
}
// Return the rest of the arguments (not the first one)
// or else an empty string slice
func (a Args) Tail() []string {
if len(a) >= 2 {
return []string(a)[1:]
}
return []string{}
}
// Checks if there are any arguments present
func (a Args) Present() bool {
return len(a) != 0
}
// 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 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
}
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func lookupInt(name string, set *flag.FlagSet) int {
f := set.Lookup(name)
if f != nil {
val, err := strconv.Atoi(f.Value.String())
if err != nil {
return 0
}
return val
}
return 0
}
func lookupDuration(name string, set *flag.FlagSet) time.Duration {
f := set.Lookup(name)
if f != nil {
val, err := time.ParseDuration(f.Value.String())
if err == nil {
return val
}
}
return 0
}
func lookupFloat64(name string, set *flag.FlagSet) float64 {
f := set.Lookup(name)
if f != nil {
val, err := strconv.ParseFloat(f.Value.String(), 64)
if err != nil {
return 0
}
return val
}
return 0
}
func lookupString(name string, set *flag.FlagSet) string {
f := set.Lookup(name)
if f != nil {
return f.Value.String()
}
return ""
}
func lookupStringSlice(name string, set *flag.FlagSet) []string {
f := set.Lookup(name)
if f != nil {
return (f.Value.(*StringSlice)).Value()
}
return nil
}
func lookupIntSlice(name string, set *flag.FlagSet) []int {
f := set.Lookup(name)
if f != nil {
return (f.Value.(*IntSlice)).Value()
}
return nil
}
func lookupGeneric(name string, set *flag.FlagSet) interface{} {
f := set.Lookup(name)
if f != nil {
return f.Value
}
return nil
}
func lookupBool(name string, set *flag.FlagSet) bool {
f := set.Lookup(name)
if f != nil {
val, err := strconv.ParseBool(f.Value.String())
if err != nil {
return false
}
return val
}
return false
}
func lookupBoolT(name string, set *flag.FlagSet) bool {
f := set.Lookup(name)
if f != nil {
val, err := strconv.ParseBool(f.Value.String())
if err != nil {
return true
}
return val
}
return false
}
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
}