aptly/cmd/string_or_file_flag.go

56 lines
1.2 KiB
Go

package cmd
import (
"io"
"os"
"strings"
"github.com/smira/flag"
)
// StringOrFileFlag is a custom flag type that can handle both string input and file input.
// If the input starts with '@', it is treated as a filename and the contents are read from the file.
// If the input is '@-', the contents are read from stdin.
type StringOrFileFlag struct {
value string
}
func (s *StringOrFileFlag) String() string {
return s.value
}
func (s *StringOrFileFlag) Set(value string) error {
var err error
s.value, err = GetStringOrFileContent(value)
return err
}
func (s *StringOrFileFlag) Get() any {
return s.value
}
func AddStringOrFileFlag(flagSet *flag.FlagSet, name string, value string, usage string) *StringOrFileFlag {
result := &StringOrFileFlag{value: value}
flagSet.Var(result, name, usage)
return result
}
func GetStringOrFileContent(value string) (string, error) {
if !strings.HasPrefix(value, "@") {
return value, nil
}
filename := strings.TrimPrefix(value, "@")
var data []byte
var err error
if filename == "-" { // Read from stdin
data, err = io.ReadAll(os.Stdin)
} else {
data, err = os.ReadFile(filename)
}
if err != nil {
return "", err
}
return string(data), nil
}