1package input
 2
 3import (
 4	"bufio"
 5	"fmt"
 6	"os"
 7	"strings"
 8)
 9
10func PromptValue(name string, preValue string) (string, error) {
11	return promptValue(name, preValue, false)
12}
13
14func PromptValueRequired(name string, preValue string) (string, error) {
15	return promptValue(name, preValue, true)
16}
17
18func promptValue(name string, preValue string, required bool) (string, error) {
19	for {
20		if preValue != "" {
21			_, _ = fmt.Fprintf(os.Stderr, "%s [%s]: ", name, preValue)
22		} else {
23			_, _ = fmt.Fprintf(os.Stderr, "%s: ", name)
24		}
25
26		line, err := bufio.NewReader(os.Stdin).ReadString('\n')
27		if err != nil {
28			return "", err
29		}
30
31		line = strings.TrimSpace(line)
32
33		if preValue != "" && line == "" {
34			return preValue, nil
35		}
36
37		if required && line == "" {
38			_, _ = fmt.Fprintf(os.Stderr, "%s is empty\n", name)
39			continue
40		}
41
42		return line, nil
43	}
44}