diff --git a/finsh/cmd.c b/finsh/cmd.c
index e23fc2e6b..9e9005d6c 100644
--- a/finsh/cmd.c
+++ b/finsh/cmd.c
@@ -379,7 +379,9 @@ void list_prefix(char* prefix)
 	const char* name_ptr;
 
 	func_cnt = 0;
-	var_cnt  = 0;
+	var_cnt  = 0;
+	name_ptr = RT_NULL;
+
 	{
 		struct finsh_syscall* index;
 		for (index = _syscall_table_begin; index < _syscall_table_end; index ++)
diff --git a/finsh/finsh.h b/finsh/finsh.h
index d97254bf9..f499016b9 100644
--- a/finsh/finsh.h
+++ b/finsh/finsh.h
@@ -68,7 +68,10 @@ char *strdup(const char *s);
 
 int isalpha( int ch );
 int atoi(const char* s);
-#else
+#else
+/* use libc of armcc */
+#include <ctype.h>
+#include <stdlib.h>
 #include <string.h>
 #endif
 #endif
diff --git a/finsh/shell.c b/finsh/shell.c
index 9144c29be..122030ff6 100644
--- a/finsh/shell.c
+++ b/finsh/shell.c
@@ -113,7 +113,8 @@ char *strdup(const char *s)
 	return tmp;
 }
 #endif
-
+
+#if !defined(__CC_ARM) && !defined(__ICCARM__)
 int isalpha( int ch )
 {
 	return (unsigned int)((ch | 0x20) - 'a') < 26u;
@@ -142,7 +143,8 @@ int atoi(const char* s)
 int isprint(unsigned char ch)
 {
     return (unsigned int)(ch - ' ') < 127u - ' ';
-}
+}
+#endif
 #endif
 
 #ifdef RT_USING_DEVICE