Rewrote the encoder to be stronger and simpler

nsencode.go

@@ -0,0 +1,88 @@
+package main
+
+import (
+	"bufio"
+	"flag"
+	"fmt"
+	"os"
+	"strings"
+	"unicode"
+)
+
+// Function to encode characters into their respective number pairs
+func encodeChar(char rune) int {
+	// Define the alphabet and numbers with a leading space
+	alphabet := " ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
+
+	// Find the index of the character
+	index := strings.IndexRune(alphabet, char)
+	if index == -1 {
+		return -1 // Return -1 if character is not found
+	}
+	return index
+}
+
+// Function to apply shift and wrap around
+func applyShift(value, shift int) int {
+	shifted := (value + shift) % 37
+	if shifted < 0 {
+		shifted += 37
+	}
+	return shifted
+}
+
+// Function to format the output based on group size
+func formatOutput(encoded []int, groupSize int) string {
+	var output strings.Builder
+	for _, num := range encoded {
+		output.WriteString(fmt.Sprintf("%02d", num))
+	}
+
+	// Apply grouping
+	finalOutput := output.String()
+	if groupSize > 0 {
+		var groupedOutput strings.Builder
+		for i := 0; i < len(finalOutput); i += groupSize {
+			if i+groupSize < len(finalOutput) {
+				groupedOutput.WriteString(finalOutput[i:i+groupSize] + " ")
+			} else {
+				groupedOutput.WriteString(finalOutput[i:])
+			}
+		}
+		return strings.TrimSpace(groupedOutput.String())
+	}
+
+	return finalOutput
+}
+
+func main() {
+	// Define command-line flags
+	shift := flag.Int("s", 0, "Shift amount for the cipher")
+	groupSize := flag.Int("g", 0, "Group size for output formatting")
+	flag.Parse()
+
+	// Read input from stdin
+	reader := bufio.NewReader(os.Stdin)
+	input, _ := reader.ReadString('\n')
+	input = strings.TrimSpace(input)
+
+	var encoded []int
+
+	// Encode the input string
+	for _, char := range input {
+		if !unicode.IsLetter(char) && !unicode.IsDigit(char) && char != ' ' {
+			continue // Skip characters not in the defined alphabet and numbers
+		}
+		encodedValue := encodeChar(unicode.ToUpper(char))
+		if encodedValue == -1 {
+			continue // Skip characters not found in the alphabet string
+		}
+		shiftedValue := applyShift(encodedValue, *shift)
+		encoded = append(encoded, shiftedValue)
+	}
+
+	// Format the output
+	formattedOutput := formatOutput(encoded, *groupSize)
+	fmt.Println(formattedOutput)
+}
+