fix(Examples): MSDK-1192: Fix Leading Spaces issue in the Flash CLI e…

…xample (#631)

* Fix Leading Spaces

* Fix Leading Spaces with Syntax

* Fix Leading Spaces with C-Lang syntax

* Fix Leading Spaces with C-Lang syntax-1

* Fix filter out arrow keys

* Fix tab space and arrow key input

* Update memmove

Examples/MAX78000/Flash_CLI/main.c

@@ -72,6 +72,19 @@ TaskHandle_t cmd_task_id;
 #define STRING(x) STRING_(x)
 #define STRING_(x) #x
 
+/* ASCII macros */
+#define END_OF_TEXT 0x03
+#define BACK_SPACE 0x08
+#define SPACE_BAR 0x20
+#define NULL_TERMINATION 0x00
+#define ARROW_KEY_CODE_1 0x1B
+#define ARROW_KEY_CODE_2 0x5B
+#define ARROW_KEY_CODE_LEFT 0x44
+#define ARROW_KEY_CODE_RIGHT 0x43
+#define ARROW_KEY_CODE_UP 0x41
+#define ARROW_KEY_CODE_DOWN 0x42
+#define TAB_SPACE 0x09
+
 /* Console ISR selection */
 #if (CONSOLE_UART == 0)
 #define UARTx_IRQHandler UART0_IRQHandler
@@ -122,6 +135,53 @@ void vCmdLineTask_cb(mxc_uart_req_t *req, int error)
  portYIELD_FROM_ISR(xHigherPriorityTaskWoken);
 }
 
+/* =| checkLeadingSpaces |======================================
+ *
+ * Function to check for the leading spaces in the 
+ * input command.
+ *
+ * If any Leading spaces are present, the function would remove 
+ * those spaces and returns a valid Null terminated command 
+ * in the same input buffer.
+ * 
+ * =============================================================
+ */
+void checkLeadingSpaces(char *buffer, unsigned int *index)
+{
+ unsigned int leadingZerosCount = 0;
+ for (leadingZerosCount = 0; leadingZerosCount < (*index); leadingZerosCount++) {
+ if (buffer[leadingZerosCount] != SPACE_BAR)
+ break;
+ }
+ if (leadingZerosCount > 0) {
+ memmove(buffer, buffer + leadingZerosCount, (*index) - leadingZerosCount);
+ *index = *index - leadingZerosCount;
+ buffer[*index] = NULL_TERMINATION;
+ ++(*index);
+ }
+}
+
+/* =| checkArrowKeys |======================================
+ *
+ * Function to check for the presence of arrow keys in the 
+ * input command.
+ *
+ * NOTE: The buffer should have atleast 3 bytes of data to 
+ * check for the arrow keys. Sanity check should be done 
+ * before calling this function.
+ * 
+ * =============================================================
+ */
+bool checkArrowKeys(char *buffer)
+{
+ if (((buffer[0] == ARROW_KEY_CODE_1) && (buffer[1] == ARROW_KEY_CODE_2)) &&
+ ((buffer[2] == ARROW_KEY_CODE_UP) || (buffer[2] == ARROW_KEY_CODE_DOWN) ||
+ (buffer[2] == ARROW_KEY_CODE_RIGHT) || (buffer[2] == ARROW_KEY_CODE_LEFT)))
+ return true;
+ else
+ return false;
+}
+
 /* =| vCmdLineTask |======================================
  *
  * The command line task provides a prompt on the serial
@@ -184,14 +244,18 @@ void vCmdLineTask(void *pvParameters)
  if (async_read_req.rxCnt > 0) {
  /* Process character */
  do {
- if (tmp == 0x08) {
+ if (tmp == BACK_SPACE) {
  /* Backspace */
  if (index > 0) {
  index--;
- printf("\x08 \x08");
+ printf("%c %c", BACK_SPACE, BACK_SPACE);
+ buffer[index] = NULL_TERMINATION;
  }
  fflush(stdout);
- } else if (tmp == 0x03) {
+ } else if (tmp == TAB_SPACE) {
+ /* Ignore Tab Space input */
+ continue;
+ } else if (tmp == END_OF_TEXT) {
  /* ^C abort */
  index = 0;
  printf("^C");
@@ -200,26 +264,42 @@ void vCmdLineTask(void *pvParameters)
  } else if ((tmp == '\r') || (tmp == '\n')) {
  printf("\r\n");
  /* Null terminate for safety */
- buffer[index] = 0x00;
+ buffer[index] = NULL_TERMINATION;
+ checkLeadingSpaces(buffer, &index);
  /* Evaluate */
- do {
- xMore = FreeRTOS_CLIProcessCommand(buffer, output, OUTPUT_BUF_SIZE);
- /* If xMore == pdTRUE, then output buffer contains no null
- * termination, so we know it is OUTPUT_BUF_SIZE. If pdFALSE, we can
- * use strlen.
- */
- for (x = 0; x < (xMore == pdTRUE ? OUTPUT_BUF_SIZE : strlen(output)); x++) {
- putchar(*(output + x));
- }
- } while (xMore != pdFALSE);
+ if (index != 0) {
+ do {
+ xMore = FreeRTOS_CLIProcessCommand(buffer, output, OUTPUT_BUF_SIZE);
+ /* If xMore == pdTRUE, then output buffer contains no null
+ * termination, so we know it is OUTPUT_BUF_SIZE. If pdFALSE, we can
+ * use strlen.
+ */
+ for (x = 0; x < (xMore == pdTRUE ? OUTPUT_BUF_SIZE : strlen(output));
+ x++) {
+ putchar(*(output + x));
+ }
+ } while (xMore != pdFALSE);
+ }
  /* New prompt */
  index = 0;
  printf("\ncmd> ");
  fflush(stdout);
  } else if (index < CMD_LINE_BUF_SIZE) {
- putchar(tmp);
  buffer[index++] = tmp;
- fflush(stdout);
+ bool arrowKey = false;
+ if (index >= 3) {
+ arrowKey = checkArrowKeys(buffer + index - 3);
+ if (arrowKey) {
+ /* Remove the arrow key from the buffer */
+ buffer[index - 3] = NULL_TERMINATION;
+ index -= 3;
+ }
+ }
+ if ((!arrowKey) && (tmp != ARROW_KEY_CODE_1) && (tmp != ARROW_KEY_CODE_2)) {
+ /* Echo out if not an arrow key */
+ putchar(tmp);
+ fflush(stdout);
+ }
  } else {
  /* Throw away data and beep terminal */
  putchar(0x07);