/os/core/src/aos_shell.c - Annotate - AMiRo-OS - Research for Cognitive Interaction

amiro-os / os / core / src / aos_shell.c @ 2c99037f

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-            e545e620
+/*
 AMiRo-OS is an operating system designed for the Autonomous Mini Robot (AMiRo) platform.
 Copyright (C) 2016..2018  Thomas Schöpping et al.
 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation, either version 3 of the License, or
 (at your option) any later version.
 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.
 You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 #include <aos_shell.h>
-            ba516b61
+#if (AMIROOS_CFG_SHELL_ENABLE == true)
-            e545e620
+#include <aos_debug.h>
 #include <aos_time.h>
 #include <aos_system.h>
 #include <string.h>
-            ba516b61
+            Thomas Schöpping
 /**
  * @brief   Event mask to be set on OS related events.
  */
 #define AOS_SHELL_EVENTMASK_OS                  EVENT_MASK(0)
 /**
  * @brief   Event mask to be set on a input event.
  */
 #define AOS_SHELL_EVENTMASK_INPUT               EVENT_MASK(1)
 /**
  * @brief   Implementation of the BaseAsynchronous write() method (inherited from BaseSequentialStream).
  */
 static size_t _channelwrite(void *instance, const uint8_t *bp, size_t n)
+{
   if (((AosShellChannel*)instance)->flags & AOS_SHELLCHANNEL_OUTPUT_ENABLED) {
-            dd8738ea
+    return streamWrite(((AosShellChannel*)instance)->asyncchannel, bp, n);
-            ba516b61
+  } else {
     return 0;
+  }
+}
 /**
  * @brief   Implementation of the BaseAsynchronous read() method (inherited from BaseSequentialStream).
  */
 static size_t _channelread(void *instance, uint8_t *bp, size_t n)
+{
-            dd8738ea
+  if (((AosShellChannel*)instance)->flags & AOS_SHELLCHANNEL_INPUT_ENABLED) {
     return streamRead(((AosShellChannel*)instance)->asyncchannel, bp, n);
   } else {
     return 0;
+  }
-            ba516b61
+            Thomas Schöpping
 /**
  * @brief   Implementation of the BaseAsynchronous put() method (inherited from BaseSequentialStream).
  */
 static msg_t _channelput(void *instance, uint8_t b)
+{
   if (((AosShellChannel*)instance)->flags & AOS_SHELLCHANNEL_OUTPUT_ENABLED) {
-            dd8738ea
+    return streamPut(((AosShellChannel*)instance)->asyncchannel, b);
-            ba516b61
+  } else {
     return MSG_RESET;
+  }
+}
 /**
  * @brief   Implementation of the BaseAsynchronous get() method (inherited from BaseSequentialStream).
  */
 static msg_t _channelget(void *instance)
+{
-            dd8738ea
+  if (((AosShellChannel*)instance)->flags & AOS_SHELLCHANNEL_INPUT_ENABLED) {
     return streamGet(((AosShellChannel*)instance)->asyncchannel);
   } else {
     return MSG_RESET;
+  }
-            ba516b61
+            Thomas Schöpping
 /**
  * @brief   Implementation of the BaseAsynchronous putt() method.
  */
-c99037f
+static msg_t _channelputt(void *instance, uint8_t b, sysinterval_t time)
-            ba516b61
+            Thomas Schöpping
   if (((AosShellChannel*)instance)->flags & AOS_SHELLCHANNEL_OUTPUT_ENABLED) {
-            dd8738ea
+    return chnPutTimeout(((AosShellChannel*)instance)->asyncchannel, b, time);
-            ba516b61
+  } else {
     return MSG_RESET;
+  }
+}
 /**
  * @brief   Implementation of the BaseAsynchronous gett() method.
  */
-c99037f
+static msg_t _channelgett(void *instance, sysinterval_t time)
-            ba516b61
+            Thomas Schöpping
-            dd8738ea
+  if (((AosShellChannel*)instance)->flags & AOS_SHELLCHANNEL_INPUT_ENABLED) {
     return chnGetTimeout(((AosShellChannel*)instance)->asyncchannel, time);
   } else {
     return MSG_RESET;
+  }
-            ba516b61
+            Thomas Schöpping
 /**
  * @brief   Implementation of the BaseAsynchronous writet() method.
  */
-c99037f
+static size_t _channelwritet(void *instance, const uint8_t *bp, size_t n, sysinterval_t time)
-            ba516b61
+            Thomas Schöpping
   if (((AosShellChannel*)instance)->flags & AOS_SHELLCHANNEL_OUTPUT_ENABLED) {
-            dd8738ea
+    return chnWriteTimeout(((AosShellChannel*)instance)->asyncchannel, bp, n, time);
-            ba516b61
+  } else {
     return 0;
+  }
+}
 /**
  * @brief   Implementation of the BaseAsynchronous readt() method.
  */
-c99037f
+static size_t _channelreadt(void *instance, uint8_t *bp, size_t n, sysinterval_t time)
-            ba516b61
+            Thomas Schöpping
-            dd8738ea
+  if (((AosShellChannel*)instance)->flags & AOS_SHELLCHANNEL_INPUT_ENABLED) {
     return chnReadTimeout(((AosShellChannel*)instance)->asyncchannel, bp, n, time);
   } else {
     return 0;
+  }
-            ba516b61
+            Thomas Schöpping
-c99037f
+/**
  * @brief   Implementation of the BaseAsynchronousChannel ctl() method.
  */
 static msg_t _channelctl(void *instance, unsigned int operation, void *arg) {
   (void) instance;
   switch (operation) {
   case CHN_CTL_NOP:
     osalDbgCheck(arg == NULL);
     break;
   case CHN_CTL_INVALID:
     osalDbgAssert(false, "invalid CTL operation");
     break;
   default:
     break;
+  }
   return MSG_OK;
+}
-            ba516b61
+static const struct AosShellChannelVMT _channelvmt = {
-be0f
+  (size_t) 0,
-            ba516b61
+  _channelwrite,
   _channelread,
   _channelput,
   _channelget,
   _channelputt,
   _channelgett,
   _channelwritet,
   _channelreadt,
-c99037f
+  _channelctl,
-            ba516b61
+};
 static size_t _streamwrite(void *instance, const uint8_t *bp, size_t n)
+{
   aosDbgCheck(instance != NULL);
   // local variables
   AosShellChannel* channel = ((AosShellStream*)instance)->channel;
   size_t bytes;
   size_t maxbytes = 0;
   // iterate through the list of channels
   while (channel != NULL) {
     bytes = streamWrite(channel, bp, n);
     maxbytes = (bytes > maxbytes) ? bytes : maxbytes;
     channel = channel->next;
+  }
   return maxbytes;
+}
 static size_t _stremread(void *instance, uint8_t *bp, size_t n)
+{
   (void)instance;
   (void)bp;
   (void)n;
   return 0;
+}
 static msg_t _streamput(void *instance, uint8_t b)
+{
   aosDbgCheck(instance != NULL);
   // local variables
   AosShellChannel* channel = ((AosShellStream*)instance)->channel;
-            dd8738ea
+  msg_t ret = MSG_OK;
-            ba516b61
+            Thomas Schöpping
   // iterate through the list of channels
   while (channel != NULL) {
-            dd8738ea
+    msg_t ret_ = streamPut(channel, b);
     ret = (ret_ < ret) ? ret_ : ret;
-            ba516b61
+    channel = channel->next;
+  }
-            dd8738ea
+  return ret;
-            ba516b61
+            Thomas Schöpping
 static msg_t _streamget(void *instance)
+{
   (void)instance;
   return 0;
+}
 static const struct AosShellStreamVMT _streamvmt = {
-be0f
+  (size_t) 0,
-            ba516b61
+  _streamwrite,
   _stremread,
   _streamput,
   _streamget,
 };
-            e545e620
+/**
  * @brief   Enumerator of special keyboard keys.
  */
 typedef enum special_key {
   KEY_UNKNOWN,      /**< any/unknow key */
   KEY_AMBIGUOUS,    /**< key is ambiguous */
   KEY_TAB,          /**< tabulator key */
   KEY_ESCAPE,       /**< escape key */
   KEY_BACKSPACE,    /**< backspace key */
   KEY_INSERT,       /**< insert key */
   KEY_DELETE,       /**< delete key */
   KEY_HOME,         /**< home key */
   KEY_END,          /**< end key */
   KEY_PAGE_UP,      /**< page up key */
   KEY_PAGE_DOWN,    /**< page down key */
   KEY_ARROW_UP,     /**< arrow up key */
   KEY_ARROW_DOWN,   /**< arrow down key */
   KEY_ARROW_LEFT,   /**< arrow left key */
   KEY_ARROW_RIGHT,  /**< arrow right key */
 } special_key_t;
 /**
  * @brief   Enumerator for case (in)sensitive character matching.
  */
 typedef enum charmatch {
   CHAR_MATCH_NOT    = 0,  /**< Characters do not match at all. */
   CHAR_MATCH_NCASE  = 1,  /**< Characters would match case insensitive. */
   CHAR_MATCH_CASE   = 2,  /**< Characters do match with case. */
 } charmatch_t;
 /**
  * @brief   Print the shell prompt
  * @details Depending on the configuration flags, the system uptime is printed before the prompt string.
+ *
  * @param[in] shell   Pointer to the shell object.
  */
 static void _printPrompt(aos_shell_t* shell)
+{
   aosDbgCheck(shell != NULL);
-aeae
+  // print some time informattion before prompt if configured
   if (shell->config & (AOS_SHELL_CONFIG_PROMPT_UPTIME | AOS_SHELL_CONFIG_PROMPT_DATETIME)) {
     // printf the system uptime
     if ((shell->config & (AOS_SHELL_CONFIG_PROMPT_UPTIME | AOS_SHELL_CONFIG_PROMPT_DATETIME)) == AOS_SHELL_CONFIG_PROMPT_UPTIME) {
       // get current system uptime
       aos_timestamp_t uptime;
       aosSysGetUptime(&uptime);
       chprintf((BaseSequentialStream*)&shell->stream, "[%01u:%02u:%02u:%02u:%03u:%03u] ",
                (uint32_t)(uptime / MICROSECONDS_PER_DAY),
                (uint8_t)(uptime % MICROSECONDS_PER_DAY / MICROSECONDS_PER_HOUR),
                (uint8_t)(uptime % MICROSECONDS_PER_HOUR / MICROSECONDS_PER_MINUTE),
                (uint8_t)(uptime % MICROSECONDS_PER_MINUTE / MICROSECONDS_PER_SECOND),
                (uint16_t)(uptime % MICROSECONDS_PER_SECOND / MICROSECONDS_PER_MILLISECOND),
                (uint16_t)(uptime % MICROSECONDS_PER_MILLISECOND / MICROSECONDS_PER_MICROSECOND));
+    }
     else if ((shell->config & (AOS_SHELL_CONFIG_PROMPT_UPTIME | AOS_SHELL_CONFIG_PROMPT_DATETIME)) == AOS_SHELL_CONFIG_PROMPT_DATETIME) {
       // get current RTC time
       struct tm dt;
       aosSysGetDateTime(&dt);
       chprintf((BaseSequentialStream*)&shell->stream, "[%02u-%02u-%04u|%02u:%02u:%02u] ",
                dt.tm_mday,
                dt.tm_mon + 1,
                dt.tm_year + 1900,
                dt.tm_hour,
                dt.tm_min,
                dt.tm_sec);
+    }
     else {
       aosDbgAssert(false);
+    }
-            e545e620
+            Thomas Schöpping
   // print the actual prompt string
   if (shell->prompt && !(shell->config & AOS_SHELL_CONFIG_PROMPT_MINIMAL)) {
-            ba516b61
+    chprintf((BaseSequentialStream*)&shell->stream, "%s$ ", shell->prompt);
-            e545e620
+  } else {
-            ba516b61
+    chprintf((BaseSequentialStream*)&shell->stream, "%>$ ");
-            e545e620
+            Thomas Schöpping
   return;
+}
 /**
  * @brief   Interprete a escape sequence
+ *
  * @param[in] seq   Character sequence to interprete.
  *                  Must be terminated by NUL byte.
+ *
  * @return          A @p special_key value.
  */
 static special_key_t _interpreteEscapeSequence(const char seq[])
+{
   // local variables
   bool ambiguous = false;
   int cmp = 0;
   // TAB
   /* not supported yet; use "\x09" instead */
   // BACKSPACE
   /* not supported yet; use "\x08" instead */
   // ESCAPE
   cmp = strcmp(seq, "\x1B");
   if (cmp == 0) {
     return KEY_ESCAPE;
   } else {
     ambiguous |= (cmp < 0);
+  }
   // INSERT
   cmp = strcmp(seq, "\x1B\x5B\x32\x7E");
   if (cmp == 0) {
     return KEY_INSERT;
   } else {
     ambiguous |= (cmp < 0);
+  }
   // DELETE
   cmp = strcmp(seq, "\x1B\x5B\x33\x7E");
   if (cmp == 0) {
     return KEY_DELETE;
   } else {
     ambiguous |= (cmp < 0);
+  }
   // HOME
   cmp = strcmp(seq, "\x1B\x4F\x48");
   if (cmp == 0) {
     return KEY_HOME;
   } else {
     ambiguous |= (cmp < 0);
+  }
   // END
   cmp = strcmp(seq, "\x1B\x4F\x46");
   if (cmp == 0) {
     return KEY_END;
   } else {
     ambiguous |= (cmp < 0);
+  }
   // PAGE UP
   cmp = strcmp(seq, "\x1B\x5B\x35\x7E");
   if (cmp == 0) {
     return KEY_PAGE_UP;
   } else {
     ambiguous |= (cmp < 0);
+  }
   // PAGE DOWN
   cmp = strcmp(seq, "\x1B\x5B\x36\x7E");
   if (cmp == 0) {
     return KEY_PAGE_DOWN;
   } else {
     ambiguous |= (cmp < 0);
+  }
   // ARROW UP
   cmp = strcmp(seq, "\x1B\x5B\x41");
   if (cmp == 0) {
     return KEY_ARROW_UP;
   } else {
     ambiguous |= (cmp < 0);
+  }
   // ARROW DOWN
   cmp = strcmp(seq, "\x1B\x5B\x42");
   if (cmp == 0) {
     return KEY_ARROW_DOWN;
   } else {
     ambiguous |= (cmp < 0);
+  }
   // ARROW LEFT
   cmp = strcmp(seq, "\x1B\x5B\x44");
   if (cmp == 0) {
     return KEY_ARROW_LEFT;
   } else {
     ambiguous |= (cmp < 0);
+  }
   // ARROW RIGHT
   cmp = strcmp(seq, "\x1B\x5B\x43");
   if (cmp == 0) {
     return KEY_ARROW_RIGHT;
   } else {
     ambiguous |= (cmp < 0);
+  }
   return ambiguous ? KEY_AMBIGUOUS : KEY_UNKNOWN;
+}
 /**
  * @brief   Move the cursor in the terminal
+ *
  * @param[in] shell   Pointer to the shell object.
  * @param[in] from    Starting position of the cursor.
  * @param[in] to      Target position to move the cursor to.
+ *
  * @return            The number of positions moved.
  */
 static int _moveCursor(aos_shell_t* shell, const size_t from, const size_t to)
+{
   aosDbgCheck(shell != NULL);
   // local variables
   size_t pos = from;
   // move cursor left by printing backspaces
   while (pos > to) {
-            ba516b61
+    streamPut(&shell->stream, '\b');
-            e545e620
+    --pos;
+  }
   // move cursor right by printing line content
   while (pos < to) {
-            ba516b61
+    streamPut(&shell->stream, shell->line[pos]);
-            e545e620
+    ++pos;
+  }
   return (int)pos - (int)from;
+}
 /**
  * @brief   Print content of the shell line
+ *
  * @param[in] shell   Pointer to the shell object.
  * @param[in] from    First position to start printing from.
  * @param[in] to      Position after the last character to print.
+ *
  * @return            Number of characters printed.
  */
 static inline size_t _printLine(aos_shell_t* shell, const size_t from, const size_t to)
+{
   aosDbgCheck(shell != NULL);
   // local variables
   size_t cnt;
   for (cnt = 0; from + cnt < to; ++cnt) {
-            ba516b61
+    streamPut(&shell->stream, shell->line[from + cnt]);
-            e545e620
+            Thomas Schöpping
   return cnt;
+}
 /**
  * @brief   Compare two characters.
+ *
  * @param[in] lhs       First character to compare.
  * @param[in] rhs       Second character to compare.
+ *
  * @return              How well the characters match.
  */
 static inline charmatch_t _charcmp(char lhs, char rhs)
+{
   // if lhs is a upper case letter and rhs is a lower case letter
   if (lhs >= 'A' && lhs <= 'Z' && rhs >= 'a' && rhs <= 'z') {
     return (lhs == (rhs - 'a' + 'A')) ? CHAR_MATCH_NCASE : CHAR_MATCH_NOT;
+  }
   // if lhs is a lower case letter and rhs is a upper case letter
   else if (lhs >= 'a' && lhs <= 'z' && rhs >= 'A' && rhs <= 'Z') {
     return ((lhs - 'a' + 'A') == rhs) ? CHAR_MATCH_NCASE : CHAR_MATCH_NOT;
+  }
   // default
   else {
     return (lhs == rhs) ? CHAR_MATCH_CASE : CHAR_MATCH_NOT;
+  }
+}
 /**
  * @brief   Maps an character from ASCII to a modified custom encoding.
  * @details The custom character encoding is very similar to ASCII and has the following structure:
  *          0x00=NULL ... 0x40='@' (identically to ASCII)
  *          0x4A='a'; 0x4B='A'; 0x4C='b'; 0x4D='B' ... 0x73='z'; 0x74='Z' (custom letter order)
  *          0x75='[' ... 0x7A='`' (0x5B..0x60 is ASCII)
  *          0x7B='{' ... 0x7F=DEL (identically to ASCII)
+ *
  * @param[in] c   Character to map to the custom encoding.
+ *
  * @return    The customly encoded character.
  */
 static inline char _mapAscii2Custom(const char c)
+{
   if (c >= 'A' && c <= 'Z') {
     return ((c - 'A') * 2) + 'A' + 1;
   } else if (c > 'Z' && c < 'a') {
     return c + ('z' - 'a') + 1;
   } else if (c >= 'a' && c <= 'z') {
     return ((c - 'a') * 2) + 'A';
   } else {
     return c;
+  }
+}
 /**
  * @brief   Compares two strings wrt letter case.
  * @details Comparisson uses a custom character encoding or mapping.
  *          See @p _mapAscii2Custom for details.
+ *
  * @param[in] str1    First string to compare.
  * @param[in] str2    Second string to compare.
  * @param[in] cs      Flag indicating whether comparison shall be case sensitive.
  * @param[in,out] n   Maximum number of character to compare (in) and number of matching characters (out).
  *                    If a null pointer is specified, this parameter is ignored.
  *                    If the value pointed to is zero, comarison will not be limited.
  * @param[out] m      Optional indicator whether there was at least one case mismatch.
+ *
  * @return      Integer value indicating the relationship between the strings.
  * @retval <0   The first character that does not match has a lower value in str1 than in str2.
  * @retval  0   The contents of both strings are equal.
  * @retval >0   The first character that does not match has a greater value in str1 than in str2.
  */
 static int _strccmp(const char *str1, const char *str2, bool cs, size_t* n, charmatch_t* m)
+{
   aosDbgCheck(str1 != NULL);
   aosDbgCheck(str2 != NULL);
   // initialize variables
   if (m) {
     *m = CHAR_MATCH_NOT;
+  }
   size_t i = 0;
   // iterate through the strings
   while ((n == NULL) || (*n == 0) || (*n > 0 && i < *n)) {
     // break on NUL
     if (str1[i] == '\0' || str2[i] == '\0') {
       if (n) {
         *n = i;
+      }
       break;
+    }
     // compare character
     const charmatch_t match = _charcmp(str1[i], str2[i]);
     if ((match == CHAR_MATCH_CASE) || (!cs && match == CHAR_MATCH_NCASE)) {
       if (m != NULL && *m != CHAR_MATCH_NCASE) {
         *m = match;
+      }
       ++i;
     } else {
       if (n) {
         *n = i;
+      }
       break;
+    }
+  }
   return _mapAscii2Custom(str1[i]) - _mapAscii2Custom(str2[i]);
+}
-            ba516b61
+static aos_status_t _readChannel(aos_shell_t* shell, AosShellChannel* channel, size_t* n)
-            e545e620
+            Thomas Schöpping
   aosDbgCheck(shell != NULL);
-            ba516b61
+  aosDbgCheck(channel != NULL);
   aosDbgCheck(n != NULL);
-            e545e620
+            Thomas Schöpping
   // local variables
-            ba516b61
+  aos_shellaction_t action = AOS_SHELL_ACTION_NONE;
-            e545e620
+  char c;
-            dd8738ea
+  special_key_t key;
-            e545e620
+            Thomas Schöpping
-            ba516b61
+  // initialize output variables
   *n = 0;
   // read character by character from the channel
   while (chnReadTimeout(channel, (uint8_t*)&c, 1, TIME_IMMEDIATE)) {
-            dd8738ea
+    key = KEY_UNKNOWN;
-            e545e620
+            Thomas Schöpping
     // parse escape sequence
-            ba516b61
+    if (shell->inputdata.escp > 0) {
       shell->inputdata.escseq[shell->inputdata.escp] = c;
       ++shell->inputdata.escp;
       key = _interpreteEscapeSequence(shell->inputdata.escseq);
-            e545e620
+      if (key == KEY_AMBIGUOUS) {
         // read next byte to resolve ambiguity
         continue;
       } else {
-            ba516b61
+        /*
          * If the escape sequence could either be parsed sucessfully
          * or there is no match (KEY_UNKNOWN),
          * reset the sequence variable and interprete key/character
          */
         shell->inputdata.escp = 0;
         memset(shell->inputdata.escseq, '\0', sizeof(shell->inputdata.escseq)*sizeof(shell->inputdata.escseq[0]));
-            e545e620
+            Thomas Schöpping
+    }
-            ba516b61
+    /* interprete keys or character */
-            e545e620
+            Thomas Schöpping
-            ba516b61
+      // default
       action = AOS_SHELL_ACTION_NONE;
       // printable character
       if (key == KEY_UNKNOWN && c >= '\x20' && c <= '\x7E') {
         action = AOS_SHELL_ACTION_READCHAR;
+      }
       // tab key or character
       else if (key == KEY_TAB || c == '\x09') {
         /*
          * pressing tab once applies auto fill
          * pressing tab a second time prints suggestions
          */
         if (shell->inputdata.lastaction == AOS_SHELL_ACTION_AUTOFILL || shell->inputdata.lastaction == AOS_SHELL_ACTION_SUGGEST) {
           action = AOS_SHELL_ACTION_SUGGEST;
-            e545e620
+        } else {
-            ba516b61
+          action = AOS_SHELL_ACTION_AUTOFILL;
-            e545e620
+            Thomas Schöpping
-            ba516b61
+            Thomas Schöpping
       // INS key
       else if (key == KEY_INSERT) {
         action = AOS_SHELL_ACTION_INSERTTOGGLE;
+      }
       // DEL key or character
       else if (key == KEY_DELETE || c == '\x7F') {
         // ignore if cursor is at very right
         if (shell->inputdata.cursorpos < shell->inputdata.lineend) {
           action = AOS_SHELL_ACTION_DELETEFORWARD;
-            e545e620
+            Thomas Schöpping
-            ba516b61
+            Thomas Schöpping
       // backspace key or character
       else if (key == KEY_BACKSPACE || c == '\x08') {
         // ignore if cursor is at very left
         if (shell->inputdata.cursorpos > 0) {
           action = AOS_SHELL_ACTION_DELETEBACKWARD;
-            e545e620
+            Thomas Schöpping
-            ba516b61
+            Thomas Schöpping
       // 'page up' of 'arrow up' key
       else if (key == KEY_PAGE_UP || key == KEY_ARROW_UP) {
-            e545e620
+        // ignore if there was some input
-            ba516b61
+        if (shell->inputdata.noinput) {
           action = AOS_SHELL_ACTION_RECALLLAST;
-            e545e620
+            Thomas Schöpping
-            ba516b61
+            Thomas Schöpping
       // 'page down' key, 'arrow done' key, 'end of test' character or 'end of transmission' character
       else if (key == KEY_PAGE_DOWN || key == KEY_ARROW_DOWN || c == '\x03' || c == '\x03') {
-            e545e620
+        // ignore if line is empty
-            ba516b61
+        if (shell->inputdata.lineend > 0) {
           action = AOS_SHELL_ACTION_CLEAR;
-            e545e620
+            Thomas Schöpping
-            ba516b61
+            Thomas Schöpping
       // 'home' key
       else if (key == KEY_HOME) {
-            e545e620
+        // ignore if cursor is very left
-            ba516b61
+        if (shell->inputdata.cursorpos > 0) {
           action = AOS_SHELL_ACTION_CURSOR2START;
-            e545e620
+            Thomas Schöpping
-            ba516b61
+            Thomas Schöpping
       // 'end' key
       else if (key == KEY_END) {
         // ignore if cursos is very right
         if (shell->inputdata.cursorpos < shell->inputdata.lineend) {
           action = AOS_SHELL_ACTION_CURSOR2END;
-            e545e620
+            Thomas Schöpping
-            ba516b61
+            Thomas Schöpping
       // 'arrow left' key
       else if (key == KEY_ARROW_LEFT) {
-            e545e620
+        // ignore if cursor is very left
-            ba516b61
+        if (shell->inputdata.cursorpos > 0) {
           action = AOS_SHELL_ACTION_CURSORLEFT;
-            e545e620
+            Thomas Schöpping
-            ba516b61
+            Thomas Schöpping
       // 'arrow right' key
       else if (key == KEY_ARROW_RIGHT) {
         // irgnore if cursor is very right
         if (shell->inputdata.cursorpos < shell->inputdata.lineend) {
           action = AOS_SHELL_ACTION_CURSORRIGHT;
-            e545e620
+            Thomas Schöpping
-            ba516b61
+            Thomas Schöpping
       // carriage return ('\r') or line feed ('\n') character
       else if (c == '\x0D' || c == '\x0A') {
         action = AOS_SHELL_ACTION_EXECUTE;
+      }
       // ESC key or [ESCAPE] character
       else if (key == KEY_ESCAPE || c == '\x1B') {
         action = AOS_SHELL_ACTION_ESCSTART;
-            e545e620
+            Thomas Schöpping
+    }
     /* handle function */
-            ba516b61
+    switch (action) {
       case AOS_SHELL_ACTION_READCHAR:
+      {
-            e545e620
+        // line is full
-            ba516b61
+        if (shell->inputdata.lineend + 1 >= shell->linesize) {
           _moveCursor(shell, shell->inputdata.cursorpos, shell->inputdata.lineend);
           chprintf((BaseSequentialStream*)&shell->stream, "\n\tmaximum line width reached\n");
-            e545e620
+          _printPrompt(shell);
-            ba516b61
+          _printLine(shell, 0, shell->inputdata.lineend);
           _moveCursor(shell, shell->inputdata.lineend, shell->inputdata.cursorpos);
-            e545e620
+            Thomas Schöpping
         // read character
         else {
           // clear old line content on first input
-            ba516b61
+          if (shell->inputdata.noinput) {
-            e545e620
+            memset(shell->line, '\0', shell->linesize);
-            ba516b61
+            shell->inputdata.noinput = false;
-            e545e620
+            Thomas Schöpping
           // overwrite content
           if (shell->config & AOS_SHELL_CONFIG_INPUT_OVERWRITE) {
-            ba516b61
+            shell->line[shell->inputdata.cursorpos] = c;
             ++shell->inputdata.cursorpos;
             shell->inputdata.lineend = (shell->inputdata.cursorpos > shell->inputdata.lineend) ? shell->inputdata.cursorpos : shell->inputdata.lineend;
             streamPut(&shell->stream, (uint8_t)c);
-            e545e620
+            Thomas Schöpping
           // insert character
           else {
-            ba516b61
+            memmove(&(shell->line[shell->inputdata.cursorpos+1]), &(shell->line[shell->inputdata.cursorpos]), shell->inputdata.lineend - shell->inputdata.cursorpos);
             shell->line[shell->inputdata.cursorpos] = c;
             ++shell->inputdata.lineend;
             _printLine(shell, shell->inputdata.cursorpos, shell->inputdata.lineend);
             ++shell->inputdata.cursorpos;
             _moveCursor(shell, shell->inputdata.lineend, shell->inputdata.cursorpos);
-            e545e620
+            Thomas Schöpping
+        }
         break;
-            ba516b61
+            Thomas Schöpping
-            e545e620
+            Thomas Schöpping
-            ba516b61
+      case AOS_SHELL_ACTION_AUTOFILL:
-            e545e620
+            Thomas Schöpping
         const char* fill = shell->line;
-            ba516b61
+        size_t cmatch = shell->inputdata.cursorpos;
-            e545e620
+        charmatch_t matchlevel = CHAR_MATCH_NOT;
         size_t n;
         // iterate through command list
         for (aos_shellcommand_t* cmd = shell->commands; cmd != NULL; cmd = cmd->next) {
           // compare current match with command
           n = cmatch;
           charmatch_t mlvl = CHAR_MATCH_NOT;
           _strccmp(fill, cmd->name, shell->config & AOS_SHELL_CONFIG_MATCH_CASE, (n == 0) ? NULL : &n, &mlvl);
           const int cmp = (n < cmatch) ?
                             (n - cmatch) :
                             (cmd->name[n] != '\0') ?
                               strlen(cmd->name) - n :
 ;
           // if an exact match was found
-            ba516b61
+          if (cmatch + cmp == shell->inputdata.cursorpos) {
             cmatch = shell->inputdata.cursorpos;
-            e545e620
+            fill = cmd->name;
             // break the loop only if there are no case mismatches with the input
-            ba516b61
+            n = shell->inputdata.cursorpos;
-            e545e620
+            _strccmp(fill, shell->line, false, &n, &mlvl);
             if (mlvl == CHAR_MATCH_CASE) {
               break;
+            }
+          }
           // if a not exact match was found
-            ba516b61
+          else if (cmatch + cmp > shell->inputdata.cursorpos) {
-            e545e620
+            // if this is the first one
             if (fill == shell->line) {
               cmatch += cmp;
               fill = cmd->name;
+            }
             // if this is a worse one
             else if ((cmp < 0) || (cmp == 0 && mlvl == CHAR_MATCH_CASE)) {
               cmatch += cmp;
+            }
+          }
           // non matching commands are ignored
           else {}
+        }
         // evaluate if there are case mismatches
         n = cmatch;
         _strccmp(shell->line, fill, shell->config & AOS_SHELL_CONFIG_MATCH_CASE, &n, &matchlevel);
         // print the auto fill if any
-            ba516b61
+        if (cmatch > shell->inputdata.cursorpos || (cmatch == shell->inputdata.cursorpos && matchlevel == CHAR_MATCH_NCASE)) {
           shell->inputdata.noinput = false;
-            e545e620
+          // limit auto fill so it will not overflow the line width
-            ba516b61
+          if (shell->inputdata.lineend + (cmatch - shell->inputdata.cursorpos) > shell->linesize) {
             cmatch = shell->linesize - shell->inputdata.lineend + shell->inputdata.cursorpos;
-            e545e620
+            Thomas Schöpping
           // move trailing memory further in the line
-            ba516b61
+          memmove(&(shell->line[cmatch]), &(shell->line[shell->inputdata.cursorpos]), shell->inputdata.lineend - shell->inputdata.cursorpos);
           shell->inputdata.lineend += cmatch - shell->inputdata.cursorpos;
-            e545e620
+          // if there was no incorrect case when matching
           if (matchlevel == CHAR_MATCH_CASE) {
             // insert fill command name to line
-            ba516b61
+            memcpy(&(shell->line[shell->inputdata.cursorpos]), &(fill[shell->inputdata.cursorpos]), cmatch - shell->inputdata.cursorpos);
-            e545e620
+            // print the output
-            ba516b61
+            _printLine(shell, shell->inputdata.cursorpos, shell->inputdata.lineend);
-            e545e620
+          } else {
             // overwrite line with fill command name
             memcpy(shell->line, fill, cmatch);
             // reprint the whole line
-            ba516b61
+            _moveCursor(shell, shell->inputdata.cursorpos, 0);
             _printLine(shell, 0, shell->inputdata.lineend);
-            e545e620
+            Thomas Schöpping
           // move cursor to the end of the matching sequence
-            ba516b61
+          shell->inputdata.cursorpos = cmatch;
           _moveCursor(shell, shell->inputdata.lineend, shell->inputdata.cursorpos);
-            e545e620
+            Thomas Schöpping
         break;
+      }
-            ba516b61
+      case AOS_SHELL_ACTION_SUGGEST:
-            e545e620
+            Thomas Schöpping
         unsigned int matches = 0;
         // iterate through command list
         for (aos_shellcommand_t* cmd = shell->commands; cmd != NULL; cmd = cmd->next) {
           // compare line content with command, excpet if cursorpos=0
-            ba516b61
+          size_t i = shell->inputdata.cursorpos;
           if (shell->inputdata.cursorpos > 0) {
-            e545e620
+            _strccmp(shell->line, cmd->name, true, &i, NULL);
+          }
-            ba516b61
+          const int cmp = (i < shell->inputdata.cursorpos) ?
                             (i - shell->inputdata.cursorpos) :
-            e545e620
+                            (cmd->name[i] != '\0') ?
                               strlen(cmd->name) - i :
 ;
           // if a match was found
           if (cmp > 0) {
             // if this is the first one
             if (matches == 0) {
-            ba516b61
+              _moveCursor(shell, shell->inputdata.cursorpos, shell->inputdata.lineend);
               streamPut(&shell->stream, '\n');
-            e545e620
+            Thomas Schöpping
             // print the command
-            ba516b61
+            chprintf((BaseSequentialStream*)&shell->stream, "\t%s\n", cmd->name);
-            e545e620
+            ++matches;
+          }
+        }
         // reprint the prompt and line if any matches have been found
         if (matches > 0) {
           _printPrompt(shell);
-            ba516b61
+          _printLine(shell, 0, shell->inputdata.lineend);
           _moveCursor(shell, shell->inputdata.lineend, shell->inputdata.cursorpos);
           shell->inputdata.noinput = false;
-            e545e620
+            Thomas Schöpping
         break;
+      }
-            ba516b61
+      case AOS_SHELL_ACTION_INSERTTOGGLE:
+      {
-            e545e620
+        if (shell->config & AOS_SHELL_CONFIG_INPUT_OVERWRITE) {
           shell->config &= ~AOS_SHELL_CONFIG_INPUT_OVERWRITE;
         } else {
           shell->config |= AOS_SHELL_CONFIG_INPUT_OVERWRITE;
+        }
         break;
-            ba516b61
+            Thomas Schöpping
-            e545e620
+            Thomas Schöpping
-            ba516b61
+      case AOS_SHELL_ACTION_DELETEFORWARD:
+      {
         --shell->inputdata.lineend;
         memmove(&(shell->line[shell->inputdata.cursorpos]), &(shell->line[shell->inputdata.cursorpos+1]), shell->inputdata.lineend - shell->inputdata.cursorpos);
         _printLine(shell, shell->inputdata.cursorpos, shell->inputdata.lineend);
         streamPut(&shell->stream, ' ');
         _moveCursor(shell, shell->inputdata.lineend + 1, shell->inputdata.cursorpos);
-            e545e620
+        break;
-            ba516b61
+            Thomas Schöpping
-            e545e620
+            Thomas Schöpping
-            ba516b61
+      case AOS_SHELL_ACTION_DELETEBACKWARD:
+      {
         --shell->inputdata.cursorpos;
         memmove(&(shell->line[shell->inputdata.cursorpos]), &(shell->line[shell->inputdata.cursorpos+1]), shell->inputdata.lineend - shell->inputdata.cursorpos);
         --shell->inputdata.lineend;
         shell->line[shell->inputdata.lineend] = '\0';
         _moveCursor(shell, shell->inputdata.cursorpos + 1, shell->inputdata.cursorpos);
         _printLine(shell, shell->inputdata.cursorpos, shell->inputdata.lineend);
         streamPut(&shell->stream, ' ');
         _moveCursor(shell, shell->inputdata.lineend+1, shell->inputdata.cursorpos);
-            e545e620
+        break;
-            ba516b61
+            Thomas Schöpping
-            e545e620
+            Thomas Schöpping
-            ba516b61
+      case AOS_SHELL_ACTION_RECALLLAST:
-            e545e620
+            Thomas Schöpping
         // replace any intermediate NUL bytes with spaces
-            ba516b61
+        shell->inputdata.lineend = 0;
-            e545e620
+        size_t nul_start = 0;
         size_t nul_end = 0;
         // search line for a NUL byte
         while (nul_start < shell->linesize) {
           if (shell->line[nul_start] == '\0') {
             nul_end = nul_start + 1;
             // keep searcjing for a byte that is not NUL
             while (nul_end < shell->linesize) {
               if (shell->line[nul_end] != '\0') {
                 // an intermediate NUL sequence was found
                 memset(&(shell->line[nul_start]), ' ', nul_end - nul_start);
-            ba516b61
+                shell->inputdata.lineend = nul_end + 1;
-            e545e620
+                break;
               } else {
                 ++nul_end;
+              }
+            }
             nul_start = nul_end + 1;
           } else {
-            ba516b61
+            ++shell->inputdata.lineend;
-            e545e620
+            ++nul_start;
+          }
+        }
-            ba516b61
+        shell->inputdata.cursorpos = shell->inputdata.lineend;
-            e545e620
+        // print the line
-            ba516b61
+        shell->inputdata.noinput = _printLine(shell, 0, shell->inputdata.lineend) == 0;
-            e545e620
+        break;
+      }
-            ba516b61
+      case AOS_SHELL_ACTION_CLEAR:
+      {
-            e545e620
+        // clear output
-            ba516b61
+        _moveCursor(shell, shell->inputdata.cursorpos, 0);
         for (shell->inputdata.cursorpos = 0; shell->inputdata.cursorpos < shell->inputdata.lineend; ++shell->inputdata.cursorpos) {
           streamPut(&shell->stream, ' ');
-            e545e620
+            Thomas Schöpping
-            ba516b61
+        _moveCursor(shell, shell->inputdata.lineend, 0);
         shell->inputdata.cursorpos = 0;
         shell->inputdata.lineend = 0;
         shell->inputdata.noinput = true;
-            e545e620
+        break;
-            ba516b61
+            Thomas Schöpping
-            e545e620
+            Thomas Schöpping
-            ba516b61
+      case AOS_SHELL_ACTION_CURSOR2START:
+      {
         _moveCursor(shell, shell->inputdata.cursorpos, 0);
         shell->inputdata.cursorpos = 0;
-            e545e620
+        break;
-            ba516b61
+            Thomas Schöpping
-            e545e620
+            Thomas Schöpping
-            ba516b61
+      case AOS_SHELL_ACTION_CURSOR2END:
+      {
         _moveCursor(shell, shell->inputdata.cursorpos, shell->inputdata.lineend);
         shell->inputdata.cursorpos = shell->inputdata.lineend;
-            e545e620
+        break;
-            ba516b61
+            Thomas Schöpping
-            e545e620
+            Thomas Schöpping
-            ba516b61
+      case AOS_SHELL_ACTION_CURSORLEFT:
+      {
         _moveCursor(shell, shell->inputdata.cursorpos, shell->inputdata.cursorpos-1);
         --shell->inputdata.cursorpos;
-            e545e620
+        break;
-            ba516b61
+            Thomas Schöpping
-            e545e620
+            Thomas Schöpping
-            ba516b61
+      case AOS_SHELL_ACTION_CURSORRIGHT:
+      {
         _moveCursor(shell, shell->inputdata.cursorpos, shell->inputdata.cursorpos+1);
         ++shell->inputdata.cursorpos;
-            e545e620
+        break;
-            ba516b61
+            Thomas Schöpping
-            e545e620
+            Thomas Schöpping
-            ba516b61
+      case AOS_SHELL_ACTION_EXECUTE:
+      {
         streamPut(&shell->stream, '\n');
         // set the number of read bytes and return
         if (!shell->inputdata.noinput) {
           *n = shell->linesize - shell->inputdata.lineend;
-            e545e620
+          // fill the remainder of the line with NUL bytes
-            ba516b61
+          memset(&(shell->line[shell->inputdata.lineend]), '\0', *n);
           // reset static variables
           shell->inputdata.noinput = true;
-            e545e620
+            Thomas Schöpping
-            ba516b61
+        return AOS_SUCCESS;
-            e545e620
+        break;
-            ba516b61
+            Thomas Schöpping
-            e545e620
+            Thomas Schöpping
-            ba516b61
+      case AOS_SHELL_ACTION_ESCSTART:
+      {
         shell->inputdata.escseq[0] = c;
         ++shell->inputdata.escp;
-            e545e620
+        break;
-            ba516b61
+            Thomas Schöpping
-            e545e620
+            Thomas Schöpping
-            ba516b61
+      case AOS_SHELL_ACTION_NONE:
-            e545e620
+      default:
-            ba516b61
+            Thomas Schöpping
-            e545e620
+        // do nothing (ignore input) and read next byte
         continue;
         break;
-            ba516b61
+            Thomas Schöpping
     } /* end of switch */
-            e545e620
+            Thomas Schöpping
-            ba516b61
+    shell->inputdata.lastaction = action;
-            e545e620
+  } /* end of while */
-            ba516b61
+  // no more data could be read from the channel
   return AOS_WARNING;
-            e545e620
+            Thomas Schöpping
 /**
  * @brief   Parses the content of the input buffer (line) to separate arguments.
+ *
  * @param[in] shell   Pointer to the shell object.
+ *
  * @return            Number of arguments found.
  */
 static size_t _parseArguments(aos_shell_t* shell)
+{
   aosDbgCheck(shell != NULL);
   /*
    * States for a very small FSM.
    */
   typedef enum {
     START,
     SPACE,
     TEXT,
     END,
   } state_t;
   // local variables
   state_t state = START;
   size_t arg = 0;
   // iterate through the line
   for (char* c = shell->line; c < shell->line + shell->linesize; ++c) {
     // terminate at first NUL byte
     if (*c == '\0') {
       state = END;
       break;
+    }
     // spaces become NUL bytes
     else if (*c == ' ') {
       *c = '\0';
       state = SPACE;
+    }
     // handle non-NUL bytes
     else {
       switch (state) {
         case START:
         case SPACE:
           // ignore too many arguments
           if (arg < shell->arglistsize) {
             shell->arglist[arg] = c;
+          }
           ++arg;
           break;
         case TEXT:
         case END:
         default:
           break;
+      }
       state = TEXT;
+    }
+  }
   // set all remaining argument pointers to NULL
   for (size_t a = arg; a < shell->arglistsize; ++a) {
     shell->arglist[a] = NULL;
+  }
   return arg;
+}
 /**
  * @brief   Initializes a shell object with the specified parameters.
+ *
  * @param[in] shell         Pointer to the shell object.
  * @param[in] stream        I/O stream to use.
  * @param[in] prompt        Prompt line to print (NULL = use default prompt).
  * @param[in] line          Pointer to the input buffer.
  * @param[in] linesize      Size of the input buffer.
  * @param[in] arglist       Pointer to the argument buffer.
  * @param[in] arglistsize   Size of te argument buffer.
  */
-            ba516b61
+void aosShellInit(aos_shell_t* shell, event_source_t* oseventsource,  const char* prompt, char* line, size_t linesize, char** arglist, size_t arglistsize)
-            e545e620
+            Thomas Schöpping
   aosDbgCheck(shell != NULL);
-            ba516b61
+  aosDbgCheck(oseventsource != NULL);
-            e545e620
+  aosDbgCheck(line != NULL);
   aosDbgCheck(arglist != NULL);
   // set parameters
   shell->thread = NULL;
   chEvtObjectInit(&shell->eventSource);
-            ba516b61
+  shell->os.eventSource = oseventsource;
   aosShellStreamInit(&shell->stream);
-            e545e620
+  shell->prompt = prompt;
   shell->commands = NULL;
   shell->execstatus.command = NULL;
   shell->execstatus.retval = 0;
   shell->line = line;
   shell->linesize = linesize;
-            ba516b61
+  shell->inputdata.lastaction = AOS_SHELL_ACTION_NONE;
   shell->inputdata.escp = 0;
   memset(shell->inputdata.escseq, '\0', sizeof(shell->inputdata.escseq)*sizeof(shell->inputdata.escseq[0]));
   shell->inputdata.cursorpos = 0;
   shell->inputdata.lineend = 0;
   shell->inputdata.noinput = true;
-            e545e620
+  shell->arglist = arglist;
   shell->arglistsize = arglistsize;
   shell->config = 0x00;
   // initialize arrays
   memset(shell->line, '\0', shell->linesize);
   for (size_t a = 0; a < shell->arglistsize; ++a) {
     shell->arglist[a] = NULL;
+  }
   return;
+}
 /**
-            ba516b61
+ * @brief   Initialize an AosShellStream object.
+ *
  * @param[in] stream  The AosShellStrem to initialize.
  */
 void aosShellStreamInit(AosShellStream* stream)
+{
   aosDbgCheck(stream != NULL);
   stream->vmt = &_streamvmt;
   stream->channel = NULL;
   return;
+}
 /**
  * @brief   Initialize an AosShellChannel object with the specified parameters.
+ *
-            dd8738ea
+ * @param[in] channel       The AosShellChannel to initialize.
  * @param[in] asyncchannel  An BaseAsynchronousChannel this AosShellChannel is associated with.
-            ba516b61
+ */
-            dd8738ea
+void aosShellChannelInit(AosShellChannel* channel, BaseAsynchronousChannel* asyncchannel)
-            ba516b61
+            Thomas Schöpping
   aosDbgCheck(channel != NULL);
-            dd8738ea
+  aosDbgCheck(asyncchannel != NULL);
-            ba516b61
+            Thomas Schöpping
   channel->vmt = &_channelvmt;
-            dd8738ea
+  channel->asyncchannel = asyncchannel;
   channel->listener.wflags = 0;
-            ba516b61
+  channel->next = NULL;
   channel->flags = 0;
   return;
+}
 /**
-            e545e620
+ * @brief   Inserts a command to the shells list of commands.
+ *
  * @param[in] shell   Pointer to the shell object.
  * @param[in] cmd     Pointer to the command to add.
+ *
  * @return            A status value.
  * @retval AOS_SUCCESS  The command was added successfully.
  * @retval AOS_ERROR    Another command with identical name already exists.
  */
 aos_status_t aosShellAddCommand(aos_shell_t *shell, aos_shellcommand_t *cmd)
+{
   aosDbgCheck(shell != NULL);
   aosDbgCheck(cmd != NULL);
   aosDbgCheck(cmd->name != NULL && strlen(cmd->name) > 0 && strchr(cmd->name, ' ') == NULL && strchr(cmd->name, '\t') == NULL);
   aosDbgCheck(cmd->callback != NULL);
   aosDbgCheck(cmd->next == NULL);
   aos_shellcommand_t* prev = NULL;
   aos_shellcommand_t** curr = &(shell->commands);
   // insert the command to the list wrt lexographical order (exception: lower case characters preceed upper their uppercase counterparts)
-            ba516b61
+  while (*curr != NULL) {
     // iterate through the list as long as the command names are 'smaller'
     const int cmp = _strccmp((*curr)->name, cmd->name, true, NULL, NULL);
     if (cmp < 0) {
       prev = *curr;
       curr = &((*curr)->next);
       continue;
+    }
     // error if the command already exists
     else if (cmp == 0) {
       return AOS_ERROR;
+    }
     // insert the command as soon as a 'larger' name was found
     else /* if (cmpval > 0) */ {
       cmd->next = *curr;
       // special case: the first command is larger
       if (prev == NULL) {
         shell->commands = cmd;
       } else {
         prev->next = cmd;
-            e545e620
+            Thomas Schöpping
-            ba516b61
+      return AOS_SUCCESS;
-            e545e620
+            Thomas Schöpping
+  }
-            ba516b61
+  // the end of the list has been reached
   // append the command
   *curr = cmd;
   return AOS_SUCCESS;
-            e545e620
+            Thomas Schöpping
 /**
  * @brief   Removes a command from the shells list of commands.
+ *
  * @param[in] shell     Pointer to the shell object.
  * @param[in] cmd       Name of the command to removde.
  * @param[out] removed  Optional pointer to the command that was removed.
+ *
  * @return              A status value.
  * @retval AOS_SUCCESS  The command was removed successfully.
  * @retval AOS_ERROR    The command name was not found.
  */
 aos_status_t aosShellRemoveCommand(aos_shell_t *shell, char *cmd, aos_shellcommand_t **removed)
+{
   aosDbgCheck(shell != NULL);
   aosDbgCheck(cmd != NULL && strlen(cmd) > 0);
   aos_shellcommand_t* prev = NULL;
   aos_shellcommand_t** curr = &(shell->commands);
   // iterate through the list and seach for the specified command name
   while (curr != NULL) {
     const int cmpval = strcmp((*curr)->name, cmd);
     // iterate through the list as long as the command names are 'smaller'
     if (cmpval < 0) {
       prev = *curr;
       curr = &((*curr)->next);
       continue;
+    }
     // remove the command when found
     else if (cmpval == 0) {
       // special case: the first command matches
       if (prev == NULL) {
         shell->commands = (*curr)->next;
       } else {
         prev->next = (*curr)->next;
+      }
       (*curr)->next = NULL;
       // set the optional output argument
       if (removed != NULL) {
         *removed = *curr;
+      }
       return AOS_SUCCESS;
+    }
     // break the loop if the command names are 'larger'
     else /* if (cmpval > 0) */ {
       break;
+    }
+  }
   // if the command was not found, return an error
   return AOS_ERROR;
+}
 /**
-            ba516b61
+ * @brief   Add a channel to a AosShellStream.
+ *
  * @param[in] stream    The AosShellStream to extend.
  * @param[in] channel   The channel to be added to the stream.
  */
 void aosShellStreamAddChannel(AosShellStream* stream, AosShellChannel* channel)
+{
   aosDbgCheck(stream != NULL);
-            dd8738ea
+  aosDbgCheck(channel != NULL && channel->asyncchannel != NULL && channel->next == NULL && (channel->flags & AOS_SHELLCHANNEL_ATTACHED) == 0);
-            ba516b61
+            Thomas Schöpping
   // prepend the new channel
   chSysLock();
   channel->flags |= AOS_SHELLCHANNEL_ATTACHED;
   channel->next = stream->channel;
   stream->channel = channel;
   chSysUnlock();
   return;
+}
 /**
  * @brief   Remove a channel from an AosShellStream.
+ *
  * @param[in] stream    The AosShellStream to modify.
  * @param[in] channel   The channel to remove.
  * @return
  */
 aos_status_t aosShellStreamRemoveChannel(AosShellStream* stream, AosShellChannel* channel)
+{
   aosDbgCheck(stream != NULL);
-            dd8738ea
+  aosDbgCheck(channel != NULL && channel->asyncchannel != NULL && channel->flags & AOS_SHELLCHANNEL_ATTACHED);
-            ba516b61
+            Thomas Schöpping
   // local varibales
   AosShellChannel* prev = NULL;
   AosShellChannel* curr = stream->channel;
   // iterate through the list and search for the specified channel
   while (curr != NULL) {
     // if the channel was found
     if (curr == channel) {
       chSysLock();
       // special case: the first channel matches (prev is NULL)
       if (prev == NULL) {
         stream->channel = curr->next;
       } else {
         prev->next = channel->next;
+      }
       curr->next = NULL;
       curr->flags &= ~AOS_SHELLCHANNEL_ATTACHED;
       chSysUnlock();
       return AOS_SUCCESS;
+    }
+  }
   // if the channel was not found, return an error
   return AOS_ERROR;
+}
 /**
  * @brief   Enable a AosSheööChannel as input.
+ *
  * @param[in] channel   The channel to enable as input.
  */
 void aosShellChannelInputEnable(AosShellChannel* channel)
+{
-            dd8738ea
+  aosDbgCheck(channel != NULL && channel->asyncchannel != NULL);
-            ba516b61
+            Thomas Schöpping
   chSysLock();
   channel->listener.wflags |= CHN_INPUT_AVAILABLE;
   channel->flags |= AOS_SHELLCHANNEL_INPUT_ENABLED;
   chSysUnlock();
   return;
+}
 /**
  * @brief   Disable a AosSheööChannel as input.
+ *
  * @param[in] channel   The channel to disable as input.
  */
 void aosShellChannelInputDisable( AosShellChannel* channel)
+{
-            dd8738ea
+  aosDbgCheck(channel != NULL && channel->asyncchannel != NULL);
-            ba516b61
+            Thomas Schöpping
   chSysLock();
   channel->listener.wflags &= ~CHN_INPUT_AVAILABLE;
   channel->flags &= ~AOS_SHELLCHANNEL_INPUT_ENABLED;
   chSysUnlock();
   return;
+}
 /**
  * @brief   Enable a AosSheööChannel as output.
+ *
  * @param[in] channel   The channel to enable as output.
  */
 void aosShellChannelOutputEnable(AosShellChannel* channel)
+{
-            dd8738ea
+  aosDbgCheck(channel != NULL && channel->asyncchannel != NULL);
-            ba516b61
+            Thomas Schöpping
   channel->flags |= AOS_SHELLCHANNEL_OUTPUT_ENABLED;
   return;
+}
 /**
  * @brief   Disable a AosSheööChannel as output.
+ *
  * @param[in] channel   The channel to disable as output.
  */
 void aosShellChannelOutputDisable(AosShellChannel* channel)
+{
-            dd8738ea
+  aosDbgCheck(channel != NULL && channel->asyncchannel != NULL);
-            ba516b61
+            Thomas Schöpping
   channel->flags &= ~AOS_SHELLCHANNEL_OUTPUT_ENABLED;
   return;
+}
 /**
-            e545e620
+ * @brief   Thread main function.
+ *
  * @param[in] aosShellThread    Name of the function;
  * @param[in] shell             Pointer to the shell object.
  */
 THD_FUNCTION(aosShellThread, shell)
+{
   aosDbgCheck(shell != NULL);
   // local variables
-            ba516b61
+  eventmask_t eventmask;
   eventflags_t eventflags;
   AosShellChannel* channel;
   aos_status_t readeval;
   size_t nchars = 0;
-            e545e620
+  size_t nargs = 0;
-            ba516b61
+  aos_shellcommand_t* cmd;
   // register OS related events
   chEvtRegisterMask(((aos_shell_t*)shell)->os.eventSource, &(((aos_shell_t*)shell)->os.eventListener), AOS_SHELL_EVENTMASK_OS);
   // register events to all input channels
   for (channel = ((aos_shell_t*)shell)->stream.channel; channel != NULL; channel = channel->next) {
-            dd8738ea
+    chEvtRegisterMaskWithFlags(&(channel->asyncchannel->event), &(channel->listener), AOS_SHELL_EVENTMASK_INPUT, channel->listener.wflags);
-            ba516b61
+            Thomas Schöpping
-            e545e620
+            Thomas Schöpping
   // fire start event
   chEvtBroadcastFlags(&(((aos_shell_t*)shell)->eventSource), AOS_SHELL_EVTFLAG_START);
-            ba516b61
+  // print the prompt for the first time
   _printPrompt((aos_shell_t*)shell);
-            e545e620
+  // enter thread loop
   while (!chThdShouldTerminateX()) {
-            ba516b61
+    // wait for event and handle it accordingly
     eventmask = chEvtWaitOne(ALL_EVENTS);
     // handle event
     switch (eventmask) {
       // OS related events
       case AOS_SHELL_EVENTMASK_OS:
+      {
         eventflags = chEvtGetAndClearFlags(&((aos_shell_t*)shell)->os.eventListener);
         // handle shutdown/restart events
         if (eventflags & AOS_SYSTEM_EVENTFLAGS_SHUTDOWN) {
           chThdTerminate(((aos_shell_t*)shell)->thread);
         } else {
           // print an error message
           chprintf((BaseSequentialStream*)&((aos_shell_t*)shell)->stream, "\nERROR: unknown OS event received (0x%08X)\n", eventflags);
+        }
-            e545e620
+        break;
+      }
-            ba516b61
+      // input events
       case AOS_SHELL_EVENTMASK_INPUT:
+      {
         // check and handle all channels
         channel = ((aos_shell_t*)shell)->stream.channel;
         while (channel != NULL) {
           eventflags = chEvtGetAndClearFlags(&channel->listener);
           // if there is new input
           if (eventflags & CHN_INPUT_AVAILABLE) {
-            dd8738ea
+            // read input from channel
             readeval = _readChannel((aos_shell_t*)shell, channel, &nchars);
             // parse input line to argument list only if the input shall be executed
             nargs = (readeval == AOS_SUCCESS && nchars > 0) ? _parseArguments((aos_shell_t*)shell) : 0;
             // check number of arguments
             if (nargs > ((aos_shell_t*)shell)->arglistsize) {
               // error too many arguments
               chprintf((BaseSequentialStream*)&((aos_shell_t*)shell)->stream, "\ttoo many arguments\n");
             } else if (nargs > 0) {
               // search command list for arg[0] and execute callback
               cmd = ((aos_shell_t*)shell)->commands;
               while (cmd != NULL) {
                 if (strcmp(((aos_shell_t*)shell)->arglist[0], cmd->name) == 0) {
                   ((aos_shell_t*)shell)->execstatus.command = cmd;
                   chEvtBroadcastFlags(&(((aos_shell_t*)shell)->eventSource), AOS_SHELL_EVTFLAG_EXEC);
                   ((aos_shell_t*)shell)->execstatus.retval = cmd->callback((BaseSequentialStream*)&((aos_shell_t*)shell)->stream, nargs, ((aos_shell_t*)shell)->arglist);
                   chEvtBroadcastFlags(&(((aos_shell_t*)shell)->eventSource), AOS_SHELL_EVTFLAG_DONE);
                   // notify if the command was not successful
                   if (((aos_shell_t*)shell)->execstatus.retval != 0) {
                     chprintf((BaseSequentialStream*)&((aos_shell_t*)shell)->stream, "command returned exit status %d\n", ((aos_shell_t*)shell)->execstatus.retval);
-            ba516b61
+            Thomas Schöpping
-            dd8738ea
+                  break;
-            ba516b61
+            Thomas Schöpping
-            dd8738ea
+                cmd = cmd->next;
               } /* end of while */
-            e545e620
+            Thomas Schöpping
-            dd8738ea
+              // if no matching command was found, print an error
               if (cmd == NULL) {
                 chprintf((BaseSequentialStream*)&((aos_shell_t*)shell)->stream, "%s: command not found\n", ((aos_shell_t*)shell)->arglist[0]);
-            ba516b61
+            Thomas Schöpping
+            }
-            dd8738ea
+            Thomas Schöpping
             // reset some internal variables and eprint a new prompt
             if (readeval == AOS_SUCCESS && !chThdShouldTerminateX()) {
               ((aos_shell_t*)shell)->inputdata.cursorpos = 0;
               ((aos_shell_t*)shell)->inputdata.lineend = 0;
               _printPrompt((aos_shell_t*)shell);
-            ba516b61
+            Thomas Schöpping
-            e545e620
+            Thomas Schöpping
-            ba516b61
+            Thomas Schöpping
           // iterate to next channel
           channel = channel->next;
-            e545e620
+            Thomas Schöpping
-            ba516b61
+        break;
-            e545e620
+            Thomas Schöpping
-            ba516b61
+            Thomas Schöpping
       // other events
       default:
+      {
         // print an error message
         chprintf((BaseSequentialStream*)&((aos_shell_t*)shell)->stream, "\nERROR: unknown event received (0x%08X)\n", eventmask);
         break;
-            e545e620
+            Thomas Schöpping
-            ba516b61
+    } /* end of switch */
   } /* end of while */
-            e545e620
+            Thomas Schöpping
   // fire event and exit the thread
   chSysLock();
   chEvtBroadcastFlagsI(&(((aos_shell_t*)shell)->eventSource), AOS_SHELL_EVTFLAG_EXIT);
   chThdExitS(MSG_OK);
   // no chSysUnlock() required since the thread has been terminated an all waiting threads have been woken up
+}
-            ba516b61
+            Thomas Schöpping
 #endif /* AMIROOS_CFG_SHELL_ENABLE == true */