urfave-cli/flag_int.go
Mostyn Bramley-Moore 500d6b04e6 Report the source of a value when we cannot parse it
If you allow a flag to be set from environment variables or files and
a parse error occurs from one of them, it is very useful for the error
message to mention where the value came from.

Without this, it can be difficult to notice an error caused by an
unexpected environment variable being set.

Implements #1167.
2020-11-03 23:57:00 +01:00

107 lines
2.2 KiB
Go

package cli
import (
"flag"
"fmt"
"strconv"
)
// IntFlag is a flag with type int
type IntFlag struct {
Name string
Aliases []string
Usage string
EnvVars []string
FilePath string
Required bool
Hidden bool
Value int
DefaultText string
Destination *int
HasBeenSet bool
}
// IsSet returns whether or not the flag has been set through env or file
func (f *IntFlag) IsSet() bool {
return f.HasBeenSet
}
// String returns a readable representation of this value
// (for usage defaults)
func (f *IntFlag) String() string {
return FlagStringer(f)
}
// Names returns the names of the flag
func (f *IntFlag) Names() []string {
return flagNames(f.Name, f.Aliases)
}
// IsRequired returns whether or not the flag is required
func (f *IntFlag) IsRequired() bool {
return f.Required
}
// TakesValue returns true of the flag takes a value, otherwise false
func (f *IntFlag) TakesValue() bool {
return true
}
// GetUsage returns the usage string for the flag
func (f *IntFlag) GetUsage() string {
return f.Usage
}
// GetValue returns the flags value as string representation and an empty
// string if the flag takes no value at all.
func (f *IntFlag) GetValue() string {
return fmt.Sprintf("%d", f.Value)
}
// Apply populates the flag given the flag set and environment
func (f *IntFlag) Apply(set *flag.FlagSet) error {
if val, ok, source := flagFromEnvOrFile(f.EnvVars, f.FilePath); ok {
if val != "" {
valInt, err := strconv.ParseInt(val, 0, 64)
if err != nil {
return fmt.Errorf("could not parse %q as int value %s for flag %s: %s", val, source, f.Name, err)
}
f.Value = int(valInt)
f.HasBeenSet = true
}
}
for _, name := range f.Names() {
if f.Destination != nil {
set.IntVar(f.Destination, name, f.Value, f.Usage)
continue
}
set.Int(name, f.Value, f.Usage)
}
return nil
}
// Int looks up the value of a local IntFlag, returns
// 0 if not found
func (c *Context) Int(name string) int {
if fs := lookupFlagSet(name, c); fs != nil {
return lookupInt(name, fs)
}
return 0
}
func lookupInt(name string, set *flag.FlagSet) int {
f := set.Lookup(name)
if f != nil {
parsed, err := strconv.ParseInt(f.Value.String(), 0, 64)
if err != nil {
return 0
}
return int(parsed)
}
return 0
}