Builtin help command function for added commands

Author: J-Rios

src/minbasecli.cpp

@@ -59,11 +59,23 @@ MINBASECLI::MINBASECLI()
 {
     this->initialized = false;
     this->received_bytes = 0;
+    this->use_builtin_help_cmd = false;
     this->num_added_commands = 0;
     this->cli_result.argc = 0U;
-    this->cli_result.argv[0][0] = '\0';
-    this->cli_result.cmd[0] = '\0';
-    this->rx_read[0] = '\0';
+    for (int i = 0; i < MINBASECLI_MAX_ARGV; i++)
+    {
+        memset(this->cli_result.argv[i], (int)('\0'),
+                MINBASECLI_MAX_ARGV_LEN - 1U);
+    }
+    memset(this->cli_result.cmd, (int)('\0'), MINBASECLI_MAX_CMD_LEN - 1U);
+    for (int i = 0; i < MINBASECLI_MAX_CMD_TO_ADD; i++)
+    {
+        this->added_commands[i].command[0] = '\0';
+        this->added_commands[i].description[0] = '\0';
+        this->added_commands[i].callback = nullptr;
+    }
+    memset(this->rx_read, (int)('\0'), MINBASECLI_MAX_READ_SIZE - 1U);
+    memset(this->print_array, (int)('\0'), MINBASECLI_MAX_PRINT_SIZE - 1U);
 }
 
 /*****************************************************************************/
@@ -120,6 +132,14 @@ bool MINBASECLI::add_cmd(const char* command,
     cmd_cb_info.description[cmd_description_len] = '\0';
     cmd_cb_info.callback = callback;
 
+    // Set to use the internal "help" command if it is the first command added
+    if (num_added_commands == 0U)
+        use_builtin_help_cmd = true;
+
+    // If requested to add a custom "help" command, don't use the builtin one
+    if (strcmp(command, CMD_HELP) == 0)
+        use_builtin_help_cmd = false;
+
     // Add the new command to the list of binded commands and increase the
     // number of added commands
     added_commands[num_added_commands] = cmd_cb_info;
@@ -147,20 +167,30 @@ bool MINBASECLI::run()
     if (manage(&cli_result) == false)
         return false;
 
-    // Check if th command is added in the callback handle list
+    // Compose array of pointer for arguments
+    char* ptr_argv[MINBASECLI_MAX_ARGV];
+    for (int i = 0; i < MINBASECLI_MAX_ARGV; i++)
+        ptr_argv[i] = cli_result.argv[i];
+
+    // If no custom "help" command is set
+    if (use_builtin_help_cmd)
+    {
+        // For "help" command, call the builtin "help" function
+        if (strcmp(cli_result.cmd, CMD_HELP) == 0U)
+        {
+            cmd_help(cli_result.argc, ptr_argv);
+            return true;
+        }
+    }
+
+    // Check if the command is added in the callback handle list
     for (uint8_t i = 0U; i < num_added_commands; i++)
     {
         // If command is found in the callbacks list, call to the callback
         if (strcmp(cli_result.cmd, added_commands[i].command) == 0U)
         {
-            // Compose array of pointer for arguments
-            char* ptr_argv[MINBASECLI_MAX_ARGV];
-            for (int i = 0; i < MINBASECLI_MAX_ARGV; i++)
-                ptr_argv[i] = cli_result.argv[i];
-
             // Call to command callback
             added_commands[i].callback(cli_result.argc, ptr_argv);
-
             cmd_found = true;
             break;
         }
@@ -343,6 +373,29 @@ void MINBASECLI::printf(const char* fstr, ...)
     va_end(lst);
 }
 
+/**
+ * @details
+ * This function is called when a "help" command is received through the CLI if
+ * any command has been added to be handled through a callback and the "help"
+ * command has not been added. It shows the list of commands that are added and
+ * the descriptions of them.
+ */
+void MINBASECLI::cmd_help(int argc, char* argv[])
+{
+    // Do nothing if there is no added commands
+    if (num_added_commands == 0U)
+        return;
+
+    // Shows each added command descriptions
+    this->printf("Available commands:\n\n");
+    for (uint8_t i = 0U; i < num_added_commands; i++)
+    {
+        this->printf("%s - %s\n", added_commands[i].command,
+                added_commands[i].description);
+    }
+    this->printf("\n");
+}
+
 /*****************************************************************************/
 
 /* Private Methods */

src/minbasecli.h

@@ -220,12 +220,29 @@ class MINBASECLI : public MINBASECLI_HAL
          */
         void printf(const char* str, ...);
 
+        /**
+         * @brief Internal builtin "help" command callback.
+         * @param argc Number of arguments.
+         * @param argv Pointers array of arguments.
+         */
+        void cmd_help(int argc, char* argv[]);
+
     /*************************************************************************/
 
     /* Private Attributes */
 
     private:
 
+        /**
+         * @brief Builtin command "help" text.
+         */
+        static constexpr char CMD_HELP[] = "help";
+
+        /**
+         * @brief Builtin command "help" description text.
+         */
+        static constexpr char CMD_HELP_DESCRIPTION[] = "Shows current info.\n";
+
         /**
          * @brief CLI initialized flag.
          */
@@ -236,6 +253,11 @@ class MINBASECLI : public MINBASECLI_HAL
          */
         uint32_t received_bytes;
 
+        /**
+         * @brief Store if the builtin "help" command has been setup.
+         */
+        bool use_builtin_help_cmd;
+
         /**
          * @brief Current number of commands added to the CLI through add()
          * function.