Add module defined prefix char check function

lexicon.txt

@@ -348,6 +348,7 @@ inet
 ingroup
 inidcate
 init
+inputchar
 inputline
 int
 interdelayms

source/cellular_at_core.c

@@ -43,10 +43,14 @@
 
 /*-----------------------------------------------------------*/
 
-#define CHECK_IS_PREFIX_CHAR( inputChar )                                 \
+#if ( CELLULAR_CONFIG_MODULE_CHECK_PFREFIX_CHAR == 0 )
+    #define CHECK_IS_PREFIX_CHAR( inputChar )                             \
     ( ( ( ( int32_t ) isalpha( ( ( int8_t ) ( inputChar ) ) ) ) == 0 ) && \
       ( ( ( int32_t ) isdigit( ( ( int8_t ) ( inputChar ) ) ) ) == 0 ) && \
       ( ( inputChar ) != '+' ) && ( ( inputChar ) != '_' ) )
+#else
+    #define CHECK_IS_PREFIX_CHAR( inputChar )    Cellular_ModuleCheckInvalidPrefixChar( inputChar )
+#endif
 
 /*-----------------------------------------------------------*/
 

source/include/cellular_config_defaults.h

@@ -361,6 +361,20 @@
     #define CELLULAR_CONFIG_STATIC_SOCKET_CONTEXT_ALLOCATION    ( 0 )
 #endif
 
+/**
+ * @brief Use module check prefix char function.<br>
+ *
+ * Enable this macro to use module defined prefix char function.
+ * Cellular_ModuleCheckIsPrefixChar function should be provided in cellular module
+ * porting.
+ *
+ * <b>Possible values:</b>`0 or 1`<br>
+ * <b>Default value (if undefined):</b> 0
+ */
+#ifndef CELLULAR_CONFIG_MODULE_CHECK_PFREFIX_CHAR
+    #define CELLULAR_CONFIG_MODULE_CHECK_PFREFIX_CHAR    ( 0 )
+#endif
+
 /**
  * @brief Macro that is called in the cellular library for logging "Error" level
  * messages.

source/include/common/cellular_common_portable.h

@@ -91,6 +91,19 @@ CellularError_t Cellular_ModuleEnableUE( CellularContext_t * pContext );
  */
 CellularError_t Cellular_ModuleEnableUrc( CellularContext_t * pContext );
 
+/**
+ * @brief Cellular module check prefix char function.
+ *
+ * This function check if the input char is valid in AT command prefix. To enable
+ * the module specific check function, set CELLULAR_CONFIG_MODULE_CHECK_PFREFIX_CHAR
+ * to 1 in "cellular_config.h".
+ *
+ * @param[in] inputChar character in prefix to be checked.
+ *
+ * @return true if this is valid prefix char. Otherwise, return false.
+ */
+bool Cellular_ModuleCheckInvalidPrefixChar( char inputChar );
+
 /* *INDENT-OFF* */
 #ifdef __cplusplus
     }