rpc: Add HelpExampleCliNamed and use it for createwallet doc

src/rpc/util.cpp

@@ -113,11 +113,63 @@ std::vector<unsigned char> ParseHexO(const UniValue& o, std::string strKey)
     return ParseHexV(find_value(o, strKey), strKey);
 }
 
+namespace {
+
+/**
+ * Quote an argument for shell.
+ *
+ * @note This is intended for help, not for security-sensitive purposes.
+ */
+std::string ShellQuote(const std::string& s)
+{
+    std::string result;
+    result.reserve(s.size() * 2);
+    for (const char ch: s) {
+        if (ch == '\'') {
+            result += "'\''";
+        } else {
+            result += ch;
+        }
+    }
+    return "'" + result + "'";
+}
+
+/**
+ * Shell-quotes the argument if it needs quoting, else returns it literally, to save typing.
+ *
+ * @note This is intended for help, not for security-sensitive purposes.
+ */
+std::string ShellQuoteIfNeeded(const std::string& s)
+{
+    for (const char ch: s) {
+        if (ch == ' ' || ch == '\'' || ch == '"') {
+            return ShellQuote(s);
+        }
+    }
+
+    return s;
+}
+
+}
+
 std::string HelpExampleCli(const std::string& methodname, const std::string& args)
 {
     return "> bitcoin-cli " + methodname + " " + args + "\n";
 }
 
+std::string HelpExampleCliNamed(const std::string& methodname, const RPCArgList& args)
+{
+    std::string result = "> bitcoin-cli -named " + methodname;
+    for (const auto& argpair: args) {
+        const auto& value = argpair.second.isStr()
+                ? argpair.second.get_str()
+                : argpair.second.write();
+        result += " " + argpair.first + "=" + ShellQuoteIfNeeded(value);
+    }
+    result += "\n";
+    return result;
+}
+
 std::string HelpExampleRpc(const std::string& methodname, const std::string& args)
 {
     return "> curl --user myusername --data-binary '{\"jsonrpc\": \"1.0\", \"id\": \"curltest\", "