added check if the current entered command matches the last command in the history buffer - if the command is already stored it will not be stored again

src/shellmatta_history.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2019 Stefan Strobel <stefan.strobel@shimatta.net>
+ * Copyright (c) 2019 - 2021 Stefan Strobel <stefan.strobel@shimatta.net>
  *
  * This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
@@ -38,7 +38,7 @@ static void appendHistoryByte(shellmatta_instance_t *inst, char byte)
     /** -# append the byte */
     inst->historyBuffer[inst->historyEnd] = byte;
 
-    /** -# check if the we overwrite an existing stored command */
+    /** -# check if we overwrite an existing stored command */
     if(inst->historyEnd == inst->historyStart)
     {
         /** -# move the start pointer to the next termination (0) */
@@ -84,6 +84,56 @@ static bool getHistoryByte(shellmatta_instance_t *inst, char *byte)
     return ret;
 }
 
+/**
+ * @brief       compares the current buffer to the last command in the history buffer
+ * @param[in]   inst    pointer to a shellmatta instance
+ * @return      true:   current command is identical to the last one in the history buffer
+ */
+static bool compareLastCommand(shellmatta_instance_t *inst)
+{
+    bool        ret = false;
+    uint32_t    i;
+    uint32_t    cnt;
+
+    /** -# check if there is anything in the buffer */
+    if(inst->historyStart != inst->historyEnd)
+    {
+        i   = inst->historyEnd;
+        cnt = 0u;
+
+        ret = true;
+
+        while((true == ret) && (cnt < inst->inputCount))
+        {
+            /** -# terminate compare on first mismatch */
+            if((inst->historyBuffer[i] != inst->buffer[cnt]) || (0u == inst->historyBuffer[i]))
+            {
+                ret = false;
+            }
+
+            if(0u == i)
+            {
+                i = inst->historyBufferSize;
+            }
+            else
+            {
+                i --;
+            }
+
+            if(cnt < inst->inputCount)
+            {
+                cnt ++;
+            }
+            else
+            {
+                ret = false;
+            }
+        }
+    }
+
+    return ret;
+}
+
 /**
  * @brief           navigates in the history buffer by the given number of commands
  * @param[in, out]  inst    pointer to a shellmatta instance
@@ -165,7 +215,7 @@ bool history_navigate(shellmatta_instance_t *inst, int32_t cnt)
 /**
  * @brief       stores the current command from the instances buffer into the
  *              history buffer
- * @param[in]   inst    pointer to a shellmatta instance
+ * @param[in]   inst        pointer to a shellmatta instance
  */
 void history_storeCmd(shellmatta_instance_t *inst)
 {
@@ -174,21 +224,19 @@ void history_storeCmd(shellmatta_instance_t *inst)
     /** -# check if we have enough room for the command in the history buffer
      * and there is a new command to be stored                              */
     if(     (inst->historyBufferSize > inst->inputCount)
-        &&  (0u != inst->inputCount)
-        &&  (true == inst->dirty))
+        &&  (0u     != inst->inputCount)
+        &&  (true   == inst->dirty)
+        &&  (true   != compareLastCommand(inst)))
     {
         /** -# append the command termination */
         appendHistoryByte(inst, 0u);
 
         /** -# append the command byte wise in reverse direction */
         for(i = inst->inputCount; i > 0u; i --)
-        {
+        { 
             appendHistoryByte(inst, inst->buffer[i - 1u]);
         }
     }
-
-    /** -# remove the dirty flag - everything is nice and saved */
-    inst->dirty = false;
 }
 
 /**
@@ -221,7 +269,6 @@ void history_restoreCmd(shellmatta_instance_t *inst)
     if(true == anythingToRestore)
     {
         utils_writeEcho(inst, inst->buffer, inst->inputCount);
-        inst->dirty = false;
     }
     (void)history_navigate(inst, 1);
 }