diff --git a/shell/main.c b/shell/main.c
index 7fcacd2..be8041a 100755
--- a/shell/main.c
+++ b/shell/main.c
@@ -1,766 +1,770 @@
-/*
-** This source file is part of MY-BASIC
-**
-** For the latest info, see https://github.com/paladin-t/my_basic/
-**
-** Copyright (C) 2011 - 2015 Wang Renxin
-**
-** Permission is hereby granted, free of charge, to any person obtaining a copy of
-** this software and associated documentation files (the "Software"), to deal in
-** the Software without restriction, including without limitation the rights to
-** use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
-** the Software, and to permit persons to whom the Software is furnished to do so,
-** subject to the following conditions:
-**
-** The above copyright notice and this permission notice shall be included in all
-** copies or substantial portions of the Software.
-**
-** THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-** IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
-** FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
-** COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
-** IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
-** CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
-*/
-
-#ifdef _MSC_VER
-#	ifndef _CRT_SECURE_NO_WARNINGS
-#		define _CRT_SECURE_NO_WARNINGS
-#	endif /* _CRT_SECURE_NO_WARNINGS */
-#endif /* _MSC_VER */
-
-#include "../core/my_basic.h"
-#ifdef _MSC_VER
-#	include <crtdbg.h>
-#	include <conio.h>
-#elif !defined __BORLANDC__
-#	include <unistd.h>
-#endif /* _MSC_VER */
-#include <assert.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-
-#ifdef _MSC_VER
-#	pragma warning(disable : 4127)
-#	pragma warning(disable : 4706)
-#	pragma warning(disable : 4996)
-#endif /* _MSC_VER */
-
-#ifdef __BORLANDC__
-#	pragma warn -8004
-#	pragma warn -8008
-#	pragma warn -8066
-#endif /* __BORLANDC__ */
-
-#ifdef __POCC__
-#	define unlink _unlink
-#	define strdup _strdup
-#endif /* __POCC__ */
-
-/*
-** {========================================================
-** Common declarations
-*/
-
-#define _USE_MEM_POOL /* Comment this macro to disable memory pool */
-
-#define _MAX_LINE_LENGTH 256
-#define _str_eq(__str1, __str2) (_strcmpi(__str1, __str2) == 0)
-
-#define _LINE_INC_STEP 16
-
-#define _NO_END(s) (MB_FUNC_OK == s || MB_FUNC_SUSPEND == s || MB_FUNC_WARNING == s || MB_FUNC_ERR == s || MB_FUNC_END == s)
-
-static struct mb_interpreter_t* bas = 0;
-
-/* ========================================================} */
-
-/*
-** {========================================================
-** Memory manipulation
-*/
-
-#ifdef _USE_MEM_POOL
-
-extern const size_t MB_SIZEOF_INT;
-extern const size_t MB_SIZEOF_PTR;
-extern const size_t MB_SIZEOF_LSN;
-extern const size_t MB_SIZEOF_HTN;
-extern const size_t MB_SIZEOF_OBJ;
-extern const size_t MB_SIZEOF_FUN;
-extern const size_t MB_SIZEOF_ARR;
-extern const size_t MB_SIZEOF_VAR;
-extern const size_t MB_SIZEOF_LBL;
-extern const size_t MB_SIZEOF_RTN;
-extern const size_t MB_SIZEOF_CLS;
-
-typedef unsigned _pool_chunk_size_t;
-
-typedef union _pool_tag_t {
-	_pool_chunk_size_t size;
-	void* ptr;
-} _pool_tag_t;
-
-typedef struct _pool_t {
-	size_t size;
-	char* stack;
-} _pool_t;
-
-static int pool_count = 0;
-
-static _pool_t* pool = 0;
-
-#define _POOL_NODE_ALLOC(size) (((char*)malloc(sizeof(_pool_tag_t) + size)) + sizeof(_pool_tag_t))
-#define _POOL_NODE_PTR(s) (s - sizeof(_pool_tag_t))
-#define _POOL_NODE_NEXT(s) (*((void**)(s - sizeof(_pool_tag_t))))
-#define _POOL_NODE_SIZE(s) (*((_pool_chunk_size_t*)(s - sizeof(_pool_tag_t))))
-#define _POOL_NODE_FREE(s) free(_POOL_NODE_PTR(s))
-
-static void _open_mem_pool(void) {
-#define N 11
-	size_t szs[N];
-	size_t lst[N];
-	int i = 0;
-	int j = 0;
-	size_t s = 0;
-
-	pool_count = 0;
-
-	szs[0] = MB_SIZEOF_INT;
-	szs[1] = MB_SIZEOF_PTR;
-	szs[2] = MB_SIZEOF_LSN;
-	szs[3] = MB_SIZEOF_HTN;
-	szs[4] = MB_SIZEOF_OBJ;
-	szs[5] = MB_SIZEOF_FUN;
-	szs[6] = MB_SIZEOF_ARR;
-	szs[7] = MB_SIZEOF_VAR;
-	szs[8] = MB_SIZEOF_LBL;
+/*
+** This source file is part of MY-BASIC
+**
+** For the latest info, see https://github.com/paladin-t/my_basic/
+**
+** Copyright (C) 2011 - 2015 Wang Renxin
+**
+** Permission is hereby granted, free of charge, to any person obtaining a copy of
+** this software and associated documentation files (the "Software"), to deal in
+** the Software without restriction, including without limitation the rights to
+** use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+** the Software, and to permit persons to whom the Software is furnished to do so,
+** subject to the following conditions:
+**
+** The above copyright notice and this permission notice shall be included in all
+** copies or substantial portions of the Software.
+**
+** THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+** IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+** FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+** COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+** IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+** CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+*/
+
+#ifdef _MSC_VER
+#	ifndef _CRT_SECURE_NO_WARNINGS
+#		define _CRT_SECURE_NO_WARNINGS
+#	endif /* _CRT_SECURE_NO_WARNINGS */
+#endif /* _MSC_VER */
+
+#include "../core/my_basic.h"
+#ifdef _MSC_VER
+#	include <crtdbg.h>
+#	include <conio.h>
+#elif !defined __BORLANDC__
+#	include <unistd.h>
+#endif /* _MSC_VER */
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#ifdef _MSC_VER
+#	pragma warning(disable : 4127)
+#	pragma warning(disable : 4706)
+#	pragma warning(disable : 4996)
+#endif /* _MSC_VER */
+
+#ifdef __BORLANDC__
+#	pragma warn -8004
+#	pragma warn -8008
+#	pragma warn -8066
+#endif /* __BORLANDC__ */
+
+#ifdef __POCC__
+#	define unlink _unlink
+#	define strdup _strdup
+#endif /* __POCC__ */
+
+/*
+** {========================================================
+** Common declarations
+*/
+
+#define _USE_MEM_POOL /* Comment this macro to disable memory pool */
+
+#define _MAX_LINE_LENGTH 256
+#define _str_eq(__str1, __str2) (_strcmpi(__str1, __str2) == 0)
+
+#define _LINE_INC_STEP 16
+
+#define _NO_END(s) (MB_FUNC_OK == s || MB_FUNC_SUSPEND == s || MB_FUNC_WARNING == s || MB_FUNC_ERR == s || MB_FUNC_END == s)
+
+static struct mb_interpreter_t* bas = 0;
+
+/* ========================================================} */
+
+/*
+** {========================================================
+** Memory manipulation
+*/
+
+#ifdef _USE_MEM_POOL
+
+extern const size_t MB_SIZEOF_INT;
+extern const size_t MB_SIZEOF_PTR;
+extern const size_t MB_SIZEOF_LSN;
+extern const size_t MB_SIZEOF_HTN;
+extern const size_t MB_SIZEOF_OBJ;
+extern const size_t MB_SIZEOF_FUN;
+extern const size_t MB_SIZEOF_ARR;
+extern const size_t MB_SIZEOF_VAR;
+extern const size_t MB_SIZEOF_LBL;
+extern const size_t MB_SIZEOF_RTN;
+extern const size_t MB_SIZEOF_CLS;
+
+typedef unsigned _pool_chunk_size_t;
+
+typedef union _pool_tag_t {
+	_pool_chunk_size_t size;
+	void* ptr;
+} _pool_tag_t;
+
+typedef struct _pool_t {
+	size_t size;
+	char* stack;
+} _pool_t;
+
+static int pool_count = 0;
+
+static _pool_t* pool = 0;
+
+#define _POOL_NODE_ALLOC(size) (((char*)malloc(sizeof(_pool_tag_t) + size)) + sizeof(_pool_tag_t))
+#define _POOL_NODE_PTR(s) (s - sizeof(_pool_tag_t))
+#define _POOL_NODE_NEXT(s) (*((void**)(s - sizeof(_pool_tag_t))))
+#define _POOL_NODE_SIZE(s) (*((_pool_chunk_size_t*)(s - sizeof(_pool_tag_t))))
+#define _POOL_NODE_FREE(s) free(_POOL_NODE_PTR(s))
+
+static void _open_mem_pool(void) {
+#define N 11
+	size_t szs[N];
+	size_t lst[N];
+	int i = 0;
+	int j = 0;
+	size_t s = 0;
+
+	pool_count = 0;
+
+	szs[0] = MB_SIZEOF_INT;
+	szs[1] = MB_SIZEOF_PTR;
+	szs[2] = MB_SIZEOF_LSN;
+	szs[3] = MB_SIZEOF_HTN;
+	szs[4] = MB_SIZEOF_OBJ;
+	szs[5] = MB_SIZEOF_FUN;
+	szs[6] = MB_SIZEOF_ARR;
+	szs[7] = MB_SIZEOF_VAR;
+	szs[8] = MB_SIZEOF_LBL;
 	szs[9] = MB_SIZEOF_RTN;
-	szs[10] = MB_SIZEOF_CLS;
-
-	memset(lst, 0, sizeof(lst));
-
-	/* Find all unduplicated sizes */
-	for(i = 0; i < N; i++) {
-		s = szs[i];
-		for(j = 0; j < N; j++) {
-			if(!lst[j]) {
-				lst[j] = s;
-				pool_count++;
-
-				break;
-			} else if(lst[j] == s) {
-				break;
-			}
-		}
-	}
-
-	pool = (_pool_t*)malloc(sizeof(_pool_t) * pool_count);
-	for(i = 0; i < pool_count; i++) {
-		pool[i].size = lst[i];
-		pool[i].stack = 0;
-	}
-#undef N
-}
-
-static void _close_mem_pool(void) {
-	int i = 0;
-	char* s = 0;
-
-	if(!pool_count)
-		return;
-
-	for(i = 0; i < pool_count; i++) {
-		while((s = pool[i].stack)) {
-			pool[i].stack = _POOL_NODE_NEXT(s);
-			_POOL_NODE_FREE(s);
-		}
-	}
-
-	free((void*)pool);
-	pool = 0;
-	pool_count = 0;
-}
-
-static char* _pop_mem(unsigned s) {
-	int i = 0;
-	_pool_t* pl = 0;
-	char* result = 0;
-
-	if(pool_count) {
-		for(i = 0; i < pool_count; i++) {
-			pl = &pool[i];
-			if(s == pl->size) {
-				if(pl->stack) {
-					/* Pop from stack */
-					result = pl->stack;
-					pl->stack = _POOL_NODE_NEXT(result);
-					_POOL_NODE_SIZE(result) = (_pool_chunk_size_t)s;
-
-					return result;
-				} else {
-					/* Create a new node */
-					result = _POOL_NODE_ALLOC(s);
-					_POOL_NODE_SIZE(result) = (_pool_chunk_size_t)s;
-
-					return result;
-				}
-			}
-		}
-	}
-
-	/* Allocate directly */
-	result = _POOL_NODE_ALLOC(s);
-	_POOL_NODE_SIZE(result) = (_pool_chunk_size_t)0;
-
-	return result;
-}
-
-static void _push_mem(char* p) {
-	int i = 0;
-	_pool_t* pl = 0;
-
-	if(pool_count) {
-		for(i = 0; i < pool_count; i++) {
-			pl = &pool[i];
-			if(_POOL_NODE_SIZE(p) == pl->size) {
-				/* Push to stack */
-				_POOL_NODE_NEXT(p) = pl->stack;
-				pl->stack = p;
-
-				return;
-			}
-		}
-	}
-
-	/* Free directly */
-	_POOL_NODE_FREE(p);
-}
-
-#endif /* _USE_MEM_POOL */
-
-/* ========================================================} */
-
-/*
-** {========================================================
-** Code manipulation
-*/
-
-typedef struct _code_line_t {
-	char** lines;
-	int count;
-	int size;
-} _code_line_t;
-
-static _code_line_t* c = 0;
-
-static _code_line_t* _create_code(void) {
-	_code_line_t* result = (_code_line_t*)malloc(sizeof(_code_line_t));
-	result->count = 0;
-	result->size = _LINE_INC_STEP;
-	result->lines = (char**)malloc(sizeof(char*) * result->size);
-
-	return result;
-}
-
-static void _destroy_code(_code_line_t* code) {
-	int i = 0;
-
-	mb_assert(code);
-
-	for(i = 0; i < code->count; ++i) {
-		free(code->lines[i]);
-	}
-	free(code->lines);
-	free(code);
-}
-
-static void _clear_code(_code_line_t* code) {
-	int i = 0;
-
-	mb_assert(code);
-
-	for(i = 0; i < code->count; ++i) {
-		free(code->lines[i]);
-	}
-	code->count = 0;
-}
-
-static void _append_line(_code_line_t* code, char* txt) {
-	int l = 0;
-	char* buf = 0;
-
-	mb_assert(code && txt);
-
-	if(code->count + 1 == code->size) {
-		code->size += _LINE_INC_STEP;
-		code->lines = (char**)realloc(code->lines, sizeof(char*) * code->size);
-	}
-	l = (int)strlen(txt);
-	buf = (char*)malloc(l + 2);
-	memcpy(buf, txt, l);
-	buf[l] = '\n';
-	buf[l + 1] = '\0';
-	code->lines[code->count++] = buf;
-}
-
-static char* _get_code(_code_line_t* code) {
-	char* result = 0;
-	int i = 0;
-
-	mb_assert(code);
-
-	result = (char*)malloc((_MAX_LINE_LENGTH + 2) * code->count + 1);
-	result[0] = '\0';
-	for(i = 0; i < code->count; ++i) {
-		result = strcat(result, code->lines[i]);
-		if(i != code->count - 1)
-			result = strcat(result, "\n");
-	}
-
-	return result;
-}
-
-static void _set_code(_code_line_t* code, char* txt) {
-	char* cursor = 0;
-	char _c = '\0';
-
-	mb_assert(code);
-
-	if(!txt)
-		return;
-
-	_clear_code(code);
-	cursor = txt;
-	do {
-		_c = *cursor;
-		if(_c == '\r' || _c == '\n' || _c == '\0') {
-			cursor[0] = '\0';
-			if(_c == '\r' && *(cursor + 1) == '\n')
-				++cursor;
-			_append_line(code, txt);
-			txt = cursor + 1;
-		}
-		++cursor;
-	} while(_c);
-}
-
-static char* _load_file(const char* path) {
-	FILE* fp = 0;
-	char* result = 0;
-	long curpos = 0;
-	long l = 0;
-
-	mb_assert(path);
-
-	fp = fopen(path, "rb");
-	if(fp) {
-		curpos = ftell(fp);
-		fseek(fp, 0L, SEEK_END);
-		l = ftell(fp);
-		fseek(fp, curpos, SEEK_SET);
-		result = (char*)malloc((size_t)(l + 1));
-		mb_assert(result);
-		fread(result, 1, l, fp);
-		fclose(fp);
-		result[l] = '\0';
-	}
-
-	return result;
-}
-
-static int _save_file(const char* path, const char* txt) {
-	FILE* fp = 0;
-
-	mb_assert(path && txt);
-
-	fp = fopen(path, "wb");
-	if(fp) {
-		fwrite(txt, sizeof(char), strlen(txt), fp);
-		fclose(fp);
-
-		return 1;
-	}
-
-	return 0;
-}
-
-/* ========================================================} */
-
-/*
-** {========================================================
-** Interactive commands
-*/
-
-static void _clear_screen(void) {
-#ifdef _MSC_VER
-	system("cls");
-#else /* _MSC_VER */
-	system("clear");
-#endif /* _MSC_VER */
-}
-
-static int _new_program(void) {
-	_clear_code(c);
-
-	return mb_reset(&bas, false);
-}
-
-static void _list_program(const char* sn, const char* cn) {
-	long lsn = 0;
-	long lcn = 0;
-
-	mb_assert(sn && cn);
-
-	lsn = atoi(sn);
-	lcn = atoi(cn);
-	if(lsn == 0 && lcn == 0) {
-		long i = 0;
-		for(i = 0; i < c->count; ++i) {
-			printf("%ld]%s", i + 1, c->lines[i]);
-		}
-	} else {
-		long i = 0;
-		long e = 0;
-		if(lsn < 1 || lsn > c->count) {
-			printf("Line number %ld out of bound.\n", lsn);
-
-			return;
-		}
-		if(lcn < 0) {
-			printf("Invalid line count %ld.\n", lcn);
-
-			return;
-		}
-		--lsn;
-		e = lcn ? lsn + lcn : c->count;
-		for(i = lsn; i < e; ++i) {
-			if(i >= c->count)
-				break;
-
-			printf("%ld]%s\n", i + 1, c->lines[i]);
-		}
-	}
-}
-
-static void _edit_program(const char* no) {
-	char line[_MAX_LINE_LENGTH];
-	long lno = 0;
-
-	mb_assert(no);
-
-	lno = atoi(no);
-	if(lno < 1 || lno > c->count) {
-		printf("Line number %ld out of bound.\n", lno);
-
-		return;
-	}
-	--lno;
-	memset(line, 0, _MAX_LINE_LENGTH);
-	printf("%ld]", lno + 1);
-	mb_gets(line, _MAX_LINE_LENGTH);
-	c->lines[lno] = (char*)realloc(c->lines[lno], strlen(line) + 1);
-	strcpy(c->lines[lno], line);
-}
-
-static void _insert_program(const char* no) {
-	char line[_MAX_LINE_LENGTH];
-	long lno = 0;
-	int i = 0;
-
-	mb_assert(no);
-
-	lno = atoi(no);
-	if(lno < 1 || lno > c->count) {
-		printf("Line number %ld out of bound.\n", lno);
-
-		return;
-	}
-	--lno;
-	memset(line, 0, _MAX_LINE_LENGTH);
-	printf("%ld]", lno + 1);
-	mb_gets(line, _MAX_LINE_LENGTH);
-	if(c->count + 1 == c->size) {
-		c->size += _LINE_INC_STEP;
-		c->lines = (char**)realloc(c->lines, sizeof(char*) * c->size);
-	}
-	for(i = c->count; i > lno; i--)
-		c->lines[i] = c->lines[i - 1];
-	c->lines[lno] = (char*)realloc(0, strlen(line) + 1);
-	strcpy(c->lines[lno], line);
-	c->count++;
-}
-
-static void _alter_program(const char* no) {
-	long lno = 0;
-	long i = 0;
-
-	mb_assert(no);
-
-	lno = atoi(no);
-	if(lno < 1 || lno > c->count) {
-		printf("Line number %ld out of bound.\n", lno);
-
-		return;
-	}
-	--lno;
-	free(c->lines[lno]);
-	for(i = lno; i < c->count - 1; i++)
-		c->lines[i] = c->lines[i + 1];
-	c->count--;
-}
-
-static void _load_program(const char* path) {
-	char* txt = _load_file(path);
-	if(txt) {
-		_new_program();
-		_set_code(c, txt);
-		free(txt);
-		if(c->count == 1) {
-			printf("Load done. %d line loaded.\n", c->count);
-		} else {
-			printf("Load done. %d lines loaded.\n", c->count);
-		}
-	} else {
-		printf("Cannot load file \"%s\"\n", path);
-	}
-}
-
-static void _save_program(const char* path) {
-	char* txt = _get_code(c);
-	if(!_save_file(path, txt)) {
-		printf("Cannot save file \"%s\"\n", path);
-	} else {
-		if(c->count == 1) {
-			printf("Save done. %d line saved.\n", c->count);
-		} else {
-			printf("Save done. %d lines saved.\n", c->count);
-		}
-	}
-	free(txt);
-}
-
-static void _kill_program(const char* path) {
-	if(!unlink(path)) {
-		printf("Delete file \"%s\" successfully.\n", path);
-	} else {
-		printf("Delete file \"%s\" failed.\n", path);
-	}
-}
-
-static void _show_tip(void) {
-	printf("MY-BASIC Interpreter Shell - %s.\n", mb_ver_string());
-	printf("Copyright (C) 2011 - 2015 Wang Renxin. All Rights Reserved.\n");
-	printf("For more information, see https://github.com/paladin-t/my_basic/.\n");
-	printf("Input HELP and hint enter to view help information.\n");
-}
-
-static void _show_help(void) {
-	printf("Commands:\n");
-	printf("  CLS   - Clear screen\n");
-	printf("  NEW   - Clear current program\n");
-	printf("  RUN   - Run current program\n");
-	printf("  BYE   - Quit interpreter\n");
-	printf("  LIST  - List current program\n");
-	printf("          Usage: LIST [l [n]], l is start line number, n is line count\n");
-	printf("  EDIT  - Edit (modify/insert/remove) a line in current program\n");
-	printf("          Usage: EDIT n, n is line number\n");
-	printf("                 EDIT -I n, insert a line before a given line, n is line number\n");
-	printf("                 EDIT -R n, remove a line, n is line number\n");
-	printf("  LOAD  - Load a file as current program\n");
-	printf("          Usage: LOAD *.*\n");
-	printf("  SAVE  - Save current program to a file\n");
-	printf("          Usage: SAVE *.*\n");
-	printf("  KILL  - Delete a file\n");
-	printf("          Usage: KILL *.*\n");
-}
-
-static int _do_line(void) {
-	int result = MB_FUNC_OK;
-	char line[_MAX_LINE_LENGTH];
-	char dup[_MAX_LINE_LENGTH];
-
-	mb_assert(bas);
-
-	memset(line, 0, _MAX_LINE_LENGTH);
-	printf("]");
-	mb_gets(line, _MAX_LINE_LENGTH);
-
-	memcpy(dup, line, _MAX_LINE_LENGTH);
-	strtok(line, " ");
-
-	if(_str_eq(line, "")) {
-		/* Do nothing */
-	} else if(_str_eq(line, "HELP")) {
-		_show_help();
-	} else if(_str_eq(line, "CLS")) {
-		_clear_screen();
-	} else if(_str_eq(line, "NEW")) {
-		result = _new_program();
-	} else if(_str_eq(line, "RUN")) {
-		int i = 0;
-		mb_assert(c);
-		result = mb_reset(&bas, false);
-		for(i = 0; i < c->count; ++i)
-			mb_load_string(bas, c->lines[i]);
-		result = mb_run(bas);
-		printf("\n");
-	} else if(_str_eq(line, "BYE")) {
-		result = MB_FUNC_BYE;
-	} else if(_str_eq(line, "LIST")) {
-		char* sn = line + strlen(line) + 1;
-		char* cn = 0;
-		strtok(sn, " ");
-		cn = sn + strlen(sn) + 1;
-		_list_program(sn, cn);
-	} else if(_str_eq(line, "EDIT")) {
-		char* no = line + strlen(line) + 1;
-		char* ne = 0;
-		strtok(no, " ");
-		ne = no + strlen(no) + 1;
-		if(!(*ne))
-			_edit_program(no);
-		else if(_str_eq(no, "-I"))
-			_insert_program(ne);
-		else if(_str_eq(no, "-R"))
-			_alter_program(ne);
-	} else if(_str_eq(line, "LOAD")) {
-		char* path = line + strlen(line) + 1;
-		_load_program(path);
-	} else if(_str_eq(line, "SAVE")) {
-		char* path = line + strlen(line) + 1;
-		_save_program(path);
-	} else if(_str_eq(line, "KILL")) {
-		char* path = line + strlen(line) + 1;
-		_kill_program(path);
-	} else {
-		_append_line(c, dup);
-	}
-
-	return result;
-}
-
-/* ========================================================} */
-
-/*
-** {========================================================
-** Scripting interfaces
-*/
-
-static int beep(struct mb_interpreter_t* s, void** l) {
-	int result = MB_FUNC_OK;
-
-	mb_assert(s && l);
-
-	mb_check(mb_attempt_func_begin(s, l));
-	mb_check(mb_attempt_func_end(s, l));
-
-	putchar('\a');
-
-	return result;
-}
-
-/* ========================================================} */
-
-/*
-** {========================================================
-** Callbacks and handlers
-*/
-
-static void _on_stepped(struct mb_interpreter_t* s, int p, unsigned short row, unsigned short col) {
-	mb_unrefvar(s);
-	mb_unrefvar(p);
-	mb_unrefvar(row);
-	mb_unrefvar(col);
-}
-
-static void _on_error(struct mb_interpreter_t* s, mb_error_e e, char* m, char* f, int p, unsigned short row, unsigned short col, int abort_code) {
-	mb_unrefvar(s);
-	mb_unrefvar(f);
-	mb_unrefvar(p);
-	if(SE_NO_ERR != e) {
-		printf("Error:\n    [LINE] %d, [COL] %d,\n    [CODE] %d, [MESSAGE] %s, [ABORT CODE] %d\n", row, col, e, m, abort_code);
-	}
-}
-
-/* ========================================================} */
-
-/*
-** {========================================================
-** Initialization and disposing
-*/
-
-static void _on_startup(void) {
-#ifdef _USE_MEM_POOL
-	_open_mem_pool();
-
-	mb_set_memory_manager(_pop_mem, _push_mem);
-#endif /* _USE_MEM_POOL */
-
-	c = _create_code();
-
-	mb_init();
-
-	mb_open(&bas);
-	mb_debug_set_stepped_handler(bas, _on_stepped);
-	mb_set_error_handler(bas, _on_error);
-
-	mb_reg_fun(bas, beep);
-}
-
-static void _on_exit(void) {
-	mb_close(&bas);
-
-	mb_dispose();
-
-	_destroy_code(c);
-	c = 0;
-
-#ifdef _USE_MEM_POOL
-	_close_mem_pool();
-#endif /* _USE_MEM_POOL */
-
-#if defined _MSC_VER && !defined _WIN64
-	if(0 != _CrtDumpMemoryLeaks()) { _asm { int 3 } }
-#endif /* _MSC_VER && !_WIN64 */
-}
-
-/* ========================================================} */
-
-/*
-** {========================================================
-** Entry
-*/
-
-int main(int argc, char* argv[]) {
-	int status = 0;
-
-#if defined _MSC_VER && !defined _WIN64
-	_CrtSetBreakAlloc(0);
-#endif /* _MSC_VER && !_WIN64 */
-
-	atexit(_on_exit);
-
-	_on_startup();
-
-	if(argc == 1) {
-		_show_tip();
-		do {
-			status = _do_line();
-		} while(_NO_END(status));
-	} else if(argc == 2) {
-		if(mb_load_file(bas, argv[1]) == MB_FUNC_OK) {
-			mb_run(bas);
-		} else {
-			printf("Invalid file\n");
-		}
-	} else {
-		printf("Unknown arguments\n");
-		_show_tip();
-	}
-
-	return 0;
-}
-
-/* ========================================================} */
+	szs[10] = MB_SIZEOF_CLS;
+
+	memset(lst, 0, sizeof(lst));
+
+	/* Find all unduplicated sizes */
+	for(i = 0; i < N; i++) {
+		s = szs[i];
+		for(j = 0; j < N; j++) {
+			if(!lst[j]) {
+				lst[j] = s;
+				pool_count++;
+
+				break;
+			} else if(lst[j] == s) {
+				break;
+			}
+		}
+	}
+
+	pool = (_pool_t*)malloc(sizeof(_pool_t) * pool_count);
+	for(i = 0; i < pool_count; i++) {
+		pool[i].size = lst[i];
+		pool[i].stack = 0;
+	}
+#undef N
+}
+
+static void _close_mem_pool(void) {
+	int i = 0;
+	char* s = 0;
+
+	if(!pool_count)
+		return;
+
+	for(i = 0; i < pool_count; i++) {
+		while((s = pool[i].stack)) {
+			pool[i].stack = _POOL_NODE_NEXT(s);
+			_POOL_NODE_FREE(s);
+		}
+	}
+
+	free((void*)pool);
+	pool = 0;
+	pool_count = 0;
+}
+
+static char* _pop_mem(unsigned s) {
+	int i = 0;
+	_pool_t* pl = 0;
+	char* result = 0;
+
+	if(pool_count) {
+		for(i = 0; i < pool_count; i++) {
+			pl = &pool[i];
+			if(s == pl->size) {
+				if(pl->stack) {
+					/* Pop from stack */
+					result = pl->stack;
+					pl->stack = _POOL_NODE_NEXT(result);
+					_POOL_NODE_SIZE(result) = (_pool_chunk_size_t)s;
+
+					return result;
+				} else {
+					/* Create a new node */
+					result = _POOL_NODE_ALLOC(s);
+					_POOL_NODE_SIZE(result) = (_pool_chunk_size_t)s;
+
+					return result;
+				}
+			}
+		}
+	}
+
+	/* Allocate directly */
+	result = _POOL_NODE_ALLOC(s);
+	_POOL_NODE_SIZE(result) = (_pool_chunk_size_t)0;
+
+	return result;
+}
+
+static void _push_mem(char* p) {
+	int i = 0;
+	_pool_t* pl = 0;
+
+	if(pool_count) {
+		for(i = 0; i < pool_count; i++) {
+			pl = &pool[i];
+			if(_POOL_NODE_SIZE(p) == pl->size) {
+				/* Push to stack */
+				_POOL_NODE_NEXT(p) = pl->stack;
+				pl->stack = p;
+
+				return;
+			}
+		}
+	}
+
+	/* Free directly */
+	_POOL_NODE_FREE(p);
+}
+
+#endif /* _USE_MEM_POOL */
+
+/* ========================================================} */
+
+/*
+** {========================================================
+** Code manipulation
+*/
+
+typedef struct _code_line_t {
+	char** lines;
+	int count;
+	int size;
+} _code_line_t;
+
+static _code_line_t* c = 0;
+
+static _code_line_t* _create_code(void) {
+	_code_line_t* result = (_code_line_t*)malloc(sizeof(_code_line_t));
+	result->count = 0;
+	result->size = _LINE_INC_STEP;
+	result->lines = (char**)malloc(sizeof(char*) * result->size);
+
+	return result;
+}
+
+static void _destroy_code(_code_line_t* code) {
+	int i = 0;
+
+	mb_assert(code);
+
+	for(i = 0; i < code->count; ++i) {
+		free(code->lines[i]);
+	}
+	free(code->lines);
+	free(code);
+}
+
+static void _clear_code(_code_line_t* code) {
+	int i = 0;
+
+	mb_assert(code);
+
+	for(i = 0; i < code->count; ++i) {
+		free(code->lines[i]);
+	}
+	code->count = 0;
+}
+
+static void _append_line(_code_line_t* code, char* txt) {
+	int l = 0;
+	char* buf = 0;
+
+	mb_assert(code && txt);
+
+	if(code->count + 1 == code->size) {
+		code->size += _LINE_INC_STEP;
+		code->lines = (char**)realloc(code->lines, sizeof(char*) * code->size);
+	}
+	l = (int)strlen(txt);
+	buf = (char*)malloc(l + 2);
+	memcpy(buf, txt, l);
+	buf[l] = '\n';
+	buf[l + 1] = '\0';
+	code->lines[code->count++] = buf;
+}
+
+static char* _get_code(_code_line_t* code) {
+	char* result = 0;
+	int i = 0;
+
+	mb_assert(code);
+
+	result = (char*)malloc((_MAX_LINE_LENGTH + 2) * code->count + 1);
+	result[0] = '\0';
+	for(i = 0; i < code->count; ++i) {
+		result = strcat(result, code->lines[i]);
+		if(i != code->count - 1)
+			result = strcat(result, "\n");
+	}
+
+	return result;
+}
+
+static void _set_code(_code_line_t* code, char* txt) {
+	char* cursor = 0;
+	char _c = '\0';
+
+	mb_assert(code);
+
+	if(!txt)
+		return;
+
+	_clear_code(code);
+	cursor = txt;
+	do {
+		_c = *cursor;
+		if(_c == '\r' || _c == '\n' || _c == '\0') {
+			cursor[0] = '\0';
+			if(_c == '\r' && *(cursor + 1) == '\n')
+				++cursor;
+			_append_line(code, txt);
+			txt = cursor + 1;
+		}
+		++cursor;
+	} while(_c);
+}
+
+static char* _load_file(const char* path) {
+	FILE* fp = 0;
+	char* result = 0;
+	long curpos = 0;
+	long l = 0;
+
+	mb_assert(path);
+
+	fp = fopen(path, "rb");
+	if(fp) {
+		curpos = ftell(fp);
+		fseek(fp, 0L, SEEK_END);
+		l = ftell(fp);
+		fseek(fp, curpos, SEEK_SET);
+		result = (char*)malloc((size_t)(l + 1));
+		mb_assert(result);
+		fread(result, 1, l, fp);
+		fclose(fp);
+		result[l] = '\0';
+	}
+
+	return result;
+}
+
+static int _save_file(const char* path, const char* txt) {
+	FILE* fp = 0;
+
+	mb_assert(path && txt);
+
+	fp = fopen(path, "wb");
+	if(fp) {
+		fwrite(txt, sizeof(char), strlen(txt), fp);
+		fclose(fp);
+
+		return 1;
+	}
+
+	return 0;
+}
+
+/* ========================================================} */
+
+/*
+** {========================================================
+** Interactive commands
+*/
+
+static void _clear_screen(void) {
+#ifdef _MSC_VER
+	system("cls");
+#else /* _MSC_VER */
+	system("clear");
+#endif /* _MSC_VER */
+}
+
+static int _new_program(void) {
+	_clear_code(c);
+
+	return mb_reset(&bas, false);
+}
+
+static void _list_program(const char* sn, const char* cn) {
+	long lsn = 0;
+	long lcn = 0;
+
+	mb_assert(sn && cn);
+
+	lsn = atoi(sn);
+	lcn = atoi(cn);
+	if(lsn == 0 && lcn == 0) {
+		long i = 0;
+		for(i = 0; i < c->count; ++i) {
+			printf("%ld]%s", i + 1, c->lines[i]);
+		}
+	} else {
+		long i = 0;
+		long e = 0;
+		if(lsn < 1 || lsn > c->count) {
+			printf("Line number %ld out of bound.\n", lsn);
+
+			return;
+		}
+		if(lcn < 0) {
+			printf("Invalid line count %ld.\n", lcn);
+
+			return;
+		}
+		--lsn;
+		e = lcn ? lsn + lcn : c->count;
+		for(i = lsn; i < e; ++i) {
+			if(i >= c->count)
+				break;
+
+			printf("%ld]%s\n", i + 1, c->lines[i]);
+		}
+	}
+}
+
+static void _edit_program(const char* no) {
+	char line[_MAX_LINE_LENGTH];
+	long lno = 0;
+	int l = 0;
+
+	mb_assert(no);
+
+	lno = atoi(no);
+	if(lno < 1 || lno > c->count) {
+		printf("Line number %ld out of bound.\n", lno);
+
+		return;
+	}
+	--lno;
+	memset(line, 0, _MAX_LINE_LENGTH);
+	printf("%ld]", lno + 1);
+	mb_gets(line, _MAX_LINE_LENGTH);
+	l = (int)strlen(line);
+	c->lines[lno] = (char*)realloc(c->lines[lno], l + 2);
+	strcpy(c->lines[lno], line);
+	c->lines[lno][l] = '\n';
+	c->lines[lno][l + 1] = '\0';
+}
+
+static void _insert_program(const char* no) {
+	char line[_MAX_LINE_LENGTH];
+	long lno = 0;
+	int i = 0;
+
+	mb_assert(no);
+
+	lno = atoi(no);
+	if(lno < 1 || lno > c->count) {
+		printf("Line number %ld out of bound.\n", lno);
+
+		return;
+	}
+	--lno;
+	memset(line, 0, _MAX_LINE_LENGTH);
+	printf("%ld]", lno + 1);
+	mb_gets(line, _MAX_LINE_LENGTH);
+	if(c->count + 1 == c->size) {
+		c->size += _LINE_INC_STEP;
+		c->lines = (char**)realloc(c->lines, sizeof(char*) * c->size);
+	}
+	for(i = c->count; i > lno; i--)
+		c->lines[i] = c->lines[i - 1];
+	c->lines[lno] = (char*)realloc(0, strlen(line) + 1);
+	strcpy(c->lines[lno], line);
+	c->count++;
+}
+
+static void _alter_program(const char* no) {
+	long lno = 0;
+	long i = 0;
+
+	mb_assert(no);
+
+	lno = atoi(no);
+	if(lno < 1 || lno > c->count) {
+		printf("Line number %ld out of bound.\n", lno);
+
+		return;
+	}
+	--lno;
+	free(c->lines[lno]);
+	for(i = lno; i < c->count - 1; i++)
+		c->lines[i] = c->lines[i + 1];
+	c->count--;
+}
+
+static void _load_program(const char* path) {
+	char* txt = _load_file(path);
+	if(txt) {
+		_new_program();
+		_set_code(c, txt);
+		free(txt);
+		if(c->count == 1) {
+			printf("Load done. %d line loaded.\n", c->count);
+		} else {
+			printf("Load done. %d lines loaded.\n", c->count);
+		}
+	} else {
+		printf("Cannot load file \"%s\"\n", path);
+	}
+}
+
+static void _save_program(const char* path) {
+	char* txt = _get_code(c);
+	if(!_save_file(path, txt)) {
+		printf("Cannot save file \"%s\"\n", path);
+	} else {
+		if(c->count == 1) {
+			printf("Save done. %d line saved.\n", c->count);
+		} else {
+			printf("Save done. %d lines saved.\n", c->count);
+		}
+	}
+	free(txt);
+}
+
+static void _kill_program(const char* path) {
+	if(!unlink(path)) {
+		printf("Delete file \"%s\" successfully.\n", path);
+	} else {
+		printf("Delete file \"%s\" failed.\n", path);
+	}
+}
+
+static void _show_tip(void) {
+	printf("MY-BASIC Interpreter Shell - %s.\n", mb_ver_string());
+	printf("Copyright (C) 2011 - 2015 Wang Renxin. All Rights Reserved.\n");
+	printf("For more information, see https://github.com/paladin-t/my_basic/.\n");
+	printf("Input HELP and hint enter to view help information.\n");
+}
+
+static void _show_help(void) {
+	printf("Commands:\n");
+	printf("  CLS   - Clear screen\n");
+	printf("  NEW   - Clear current program\n");
+	printf("  RUN   - Run current program\n");
+	printf("  BYE   - Quit interpreter\n");
+	printf("  LIST  - List current program\n");
+	printf("          Usage: LIST [l [n]], l is start line number, n is line count\n");
+	printf("  EDIT  - Edit (modify/insert/remove) a line in current program\n");
+	printf("          Usage: EDIT n, n is line number\n");
+	printf("                 EDIT -I n, insert a line before a given line, n is line number\n");
+	printf("                 EDIT -R n, remove a line, n is line number\n");
+	printf("  LOAD  - Load a file as current program\n");
+	printf("          Usage: LOAD *.*\n");
+	printf("  SAVE  - Save current program to a file\n");
+	printf("          Usage: SAVE *.*\n");
+	printf("  KILL  - Delete a file\n");
+	printf("          Usage: KILL *.*\n");
+}
+
+static int _do_line(void) {
+	int result = MB_FUNC_OK;
+	char line[_MAX_LINE_LENGTH];
+	char dup[_MAX_LINE_LENGTH];
+
+	mb_assert(bas);
+
+	memset(line, 0, _MAX_LINE_LENGTH);
+	printf("]");
+	mb_gets(line, _MAX_LINE_LENGTH);
+
+	memcpy(dup, line, _MAX_LINE_LENGTH);
+	strtok(line, " ");
+
+	if(_str_eq(line, "")) {
+		/* Do nothing */
+	} else if(_str_eq(line, "HELP")) {
+		_show_help();
+	} else if(_str_eq(line, "CLS")) {
+		_clear_screen();
+	} else if(_str_eq(line, "NEW")) {
+		result = _new_program();
+	} else if(_str_eq(line, "RUN")) {
+		int i = 0;
+		mb_assert(c);
+		result = mb_reset(&bas, false);
+		for(i = 0; i < c->count; ++i)
+			mb_load_string(bas, c->lines[i]);
+		result = mb_run(bas);
+		printf("\n");
+	} else if(_str_eq(line, "BYE")) {
+		result = MB_FUNC_BYE;
+	} else if(_str_eq(line, "LIST")) {
+		char* sn = line + strlen(line) + 1;
+		char* cn = 0;
+		strtok(sn, " ");
+		cn = sn + strlen(sn) + 1;
+		_list_program(sn, cn);
+	} else if(_str_eq(line, "EDIT")) {
+		char* no = line + strlen(line) + 1;
+		char* ne = 0;
+		strtok(no, " ");
+		ne = no + strlen(no) + 1;
+		if(!(*ne))
+			_edit_program(no);
+		else if(_str_eq(no, "-I"))
+			_insert_program(ne);
+		else if(_str_eq(no, "-R"))
+			_alter_program(ne);
+	} else if(_str_eq(line, "LOAD")) {
+		char* path = line + strlen(line) + 1;
+		_load_program(path);
+	} else if(_str_eq(line, "SAVE")) {
+		char* path = line + strlen(line) + 1;
+		_save_program(path);
+	} else if(_str_eq(line, "KILL")) {
+		char* path = line + strlen(line) + 1;
+		_kill_program(path);
+	} else {
+		_append_line(c, dup);
+	}
+
+	return result;
+}
+
+/* ========================================================} */
+
+/*
+** {========================================================
+** Scripting interfaces
+*/
+
+static int beep(struct mb_interpreter_t* s, void** l) {
+	int result = MB_FUNC_OK;
+
+	mb_assert(s && l);
+
+	mb_check(mb_attempt_func_begin(s, l));
+	mb_check(mb_attempt_func_end(s, l));
+
+	putchar('\a');
+
+	return result;
+}
+
+/* ========================================================} */
+
+/*
+** {========================================================
+** Callbacks and handlers
+*/
+
+static void _on_stepped(struct mb_interpreter_t* s, int p, unsigned short row, unsigned short col) {
+	mb_unrefvar(s);
+	mb_unrefvar(p);
+	mb_unrefvar(row);
+	mb_unrefvar(col);
+}
+
+static void _on_error(struct mb_interpreter_t* s, mb_error_e e, char* m, char* f, int p, unsigned short row, unsigned short col, int abort_code) {
+	mb_unrefvar(s);
+	mb_unrefvar(f);
+	mb_unrefvar(p);
+	if(SE_NO_ERR != e) {
+		printf("Error:\n    [LINE] %d, [COL] %d,\n    [CODE] %d, [MESSAGE] %s, [ABORT CODE] %d\n", row, col, e, m, abort_code);
+	}
+}
+
+/* ========================================================} */
+
+/*
+** {========================================================
+** Initialization and disposing
+*/
+
+static void _on_startup(void) {
+#ifdef _USE_MEM_POOL
+	_open_mem_pool();
+
+	mb_set_memory_manager(_pop_mem, _push_mem);
+#endif /* _USE_MEM_POOL */
+
+	c = _create_code();
+
+	mb_init();
+
+	mb_open(&bas);
+	mb_debug_set_stepped_handler(bas, _on_stepped);
+	mb_set_error_handler(bas, _on_error);
+
+	mb_reg_fun(bas, beep);
+}
+
+static void _on_exit(void) {
+	mb_close(&bas);
+
+	mb_dispose();
+
+	_destroy_code(c);
+	c = 0;
+
+#ifdef _USE_MEM_POOL
+	_close_mem_pool();
+#endif /* _USE_MEM_POOL */
+
+#if defined _MSC_VER && !defined _WIN64
+	if(0 != _CrtDumpMemoryLeaks()) { _asm { int 3 } }
+#endif /* _MSC_VER && !_WIN64 */
+}
+
+/* ========================================================} */
+
+/*
+** {========================================================
+** Entry
+*/
+
+int main(int argc, char* argv[]) {
+	int status = 0;
+
+#if defined _MSC_VER && !defined _WIN64
+	_CrtSetBreakAlloc(0);
+#endif /* _MSC_VER && !_WIN64 */
+
+	atexit(_on_exit);
+
+	_on_startup();
+
+	if(argc == 1) {
+		_show_tip();
+		do {
+			status = _do_line();
+		} while(_NO_END(status));
+	} else if(argc == 2) {
+		if(mb_load_file(bas, argv[1]) == MB_FUNC_OK) {
+			mb_run(bas);
+		} else {
+			printf("Invalid file\n");
+		}
+	} else {
+		printf("Unknown arguments\n");
+		_show_tip();
+	}
+
+	return 0;
+}
+
+/* ========================================================} */