github.com/Finschia/finschia-sdk@v0.48.1/client/input/input.go (about)

     1  package input
     2  
     3  import (
     4  	"bufio"
     5  	"errors"
     6  	"fmt"
     7  	"io"
     8  	"os"
     9  	"strings"
    10  
    11  	"github.com/bgentry/speakeasy"
    12  	isatty "github.com/mattn/go-isatty"
    13  )
    14  
    15  // MinPassLength is the minimum acceptable password length
    16  const MinPassLength = 8
    17  
    18  // GetPassword will prompt for a password one-time (to sign a tx)
    19  // It enforces the password length
    20  func GetPassword(prompt string, buf *bufio.Reader) (pass string, err error) {
    21  	if inputIsTty() {
    22  		pass, err = speakeasy.FAsk(os.Stderr, prompt)
    23  	} else {
    24  		pass, err = readLineFromBuf(buf)
    25  	}
    26  
    27  	if err != nil {
    28  		return "", err
    29  	}
    30  
    31  	if len(pass) < MinPassLength {
    32  		// Return the given password to the upstream client so it can handle a
    33  		// non-STDIN failure gracefully.
    34  		return pass, fmt.Errorf("password must be at least %d characters", MinPassLength)
    35  	}
    36  
    37  	return pass, nil
    38  }
    39  
    40  // GetConfirmation will request user give the confirmation from stdin.
    41  // "y", "Y", "yes", "YES", and "Yes" all count as confirmations.
    42  // If the input is not recognized, it returns false and a nil error.
    43  func GetConfirmation(prompt string, r *bufio.Reader, w io.Writer) (bool, error) {
    44  	if inputIsTty() {
    45  		fmt.Fprintf(w, "%s [y/N]: ", prompt)
    46  	}
    47  
    48  	response, err := readLineFromBuf(r)
    49  	if err != nil {
    50  		return false, err
    51  	}
    52  
    53  	response = strings.TrimSpace(response)
    54  	if len(response) == 0 {
    55  		return false, nil
    56  	}
    57  
    58  	response = strings.ToLower(response)
    59  	if response[0] == 'y' {
    60  		return true, nil
    61  	}
    62  
    63  	return false, nil
    64  }
    65  
    66  // GetString simply returns the trimmed string output of a given reader.
    67  func GetString(prompt string, buf *bufio.Reader) (string, error) {
    68  	if inputIsTty() && prompt != "" {
    69  		fmt.Fprintf(os.Stderr, "> %s\n", prompt)
    70  	}
    71  
    72  	out, err := readLineFromBuf(buf)
    73  	if err != nil {
    74  		return "", err
    75  	}
    76  
    77  	return strings.TrimSpace(out), nil
    78  }
    79  
    80  // inputIsTty returns true iff we have an interactive prompt,
    81  // where we can disable echo and request to repeat the password.
    82  // If false, we can optimize for piped input from another command
    83  func inputIsTty() bool {
    84  	return isatty.IsTerminal(os.Stdin.Fd()) || isatty.IsCygwinTerminal(os.Stdin.Fd())
    85  }
    86  
    87  // readLineFromBuf reads one line from reader.
    88  // Subsequent calls reuse the same buffer, so we don't lose
    89  // any input when reading a password twice (to verify)
    90  func readLineFromBuf(buf *bufio.Reader) (string, error) {
    91  	pass, err := buf.ReadString('\n')
    92  
    93  	switch {
    94  	case errors.Is(err, io.EOF):
    95  		// If by any chance the error is EOF, but we were actually able to read
    96  		// something from the reader then don't return the EOF error.
    97  		// If we didn't read anything from the reader and got the EOF error, then
    98  		// it's safe to return EOF back to the caller.
    99  		if len(pass) > 0 {
   100  			// exit the switch statement
   101  			break
   102  		}
   103  		return "", err
   104  
   105  	case err != nil:
   106  		return "", err
   107  	}
   108  
   109  	return strings.TrimSpace(pass), nil
   110  }