Add initial gpgToRCW conversion program

extra/conversion-scripts/gpgToRCW/gpg.go

@@ -0,0 +1,19 @@
+package main
+
+import (
+	"os/exec"
+	"strings"
+
+	"github.com/rwinkhart/go-boilerplate/back"
+	"github.com/rwinkhart/libmutton/core"
+)
+
+// decryptGPG decrypts a GPG-encrypted file and returns the contents as a slice of (trimmed) strings.
+func decryptGPG(targetLocation string) []string {
+	cmd := exec.Command("gpg", "--pinentry-mode", "loopback", "-q", "-d", targetLocation)
+	output, err := cmd.Output()
+	if err != nil {
+		back.PrintError("Failed to decrypt \""+targetLocation+"\" - Ensure it is a valid GPG-encrypted file and that you entered your passphrase correctly", core.ErrorDecryption, true)
+	}
+	return strings.Split(string(output), "\n")
+}