diff --git a/LICENSE b/LICENSE
index b9947cc..26ffccb 100644
--- a/LICENSE
+++ b/LICENSE
@@ -1,6 +1,6 @@
 The MIT License (MIT)
 
-Copyright (c) 2015-2018 Armink (armink.ztl@gmail.com)
+Copyright (c) 2015-2019 Armink (armink.ztl@gmail.com)
 
 Permission is hereby granted, free of charge, to any person obtaining
 a copy of this software and associated documentation files (the
diff --git a/demo/os/linux/easylogger/plugins/file/elog_file_cfg.h b/demo/os/linux/easylogger/plugins/file/elog_file_cfg.h
index 278b48e..f43f98a 100644
--- a/demo/os/linux/easylogger/plugins/file/elog_file_cfg.h
+++ b/demo/os/linux/easylogger/plugins/file/elog_file_cfg.h
@@ -35,4 +35,7 @@
 /* EasyLogger file log plugin's using file max size */
 #define ELOG_FILE_MAX_SIZE  (10 * 1024 * 1024)
 
+/* EasyLogger file log plugin's using max rotate file count */
+#define ELOG_FILE_MAX_ROTATE 10
+
 #endif /* _ELOG_FILE_CFG_H_ */
diff --git a/easylogger/inc/elog.h b/easylogger/inc/elog.h
index caa28f4..6d0f971 100644
--- a/easylogger/inc/elog.h
+++ b/easylogger/inc/elog.h
@@ -1,7 +1,7 @@
 /*
  * This file is part of the EasyLogger Library.
  *
- * Copyright (c) 2015-2018, Armink, <armink.ztl@gmail.com>
+ * Copyright (c) 2015-2019, Armink, <armink.ztl@gmail.com>
  *
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files (the
@@ -50,7 +50,7 @@ extern "C" {
 #define ELOG_LVL_TOTAL_NUM                   6
 
 /* EasyLogger software version number */
-#define ELOG_SW_VERSION                      "2.0.3"
+#define ELOG_SW_VERSION                      "2.1.99"
 
 /* EasyLogger assert for developer. */
 #ifdef ELOG_ASSERT_ENABLE
@@ -69,12 +69,12 @@ extern "C" {
 #endif
 
 #ifndef ELOG_OUTPUT_ENABLE
-    #define elog_a(tag, ...)
-    #define elog_e(tag, ...)
-    #define elog_w(tag, ...)
-    #define elog_i(tag, ...)
-    #define elog_d(tag, ...)
-    #define elog_v(tag, ...)
+    #define elog_assert(tag, ...)
+    #define elog_error(tag, ...)
+    #define elog_warn(tag, ...)
+    #define elog_info(tag, ...)
+    #define elog_debug(tag, ...)
+    #define elog_verbose(tag, ...)
 #else /* ELOG_OUTPUT_ENABLE */
     #if ELOG_OUTPUT_LVL >= ELOG_LVL_ASSERT
         #define elog_assert(tag, ...) \
diff --git a/easylogger/plugins/file/elog_file.c b/easylogger/plugins/file/elog_file.c
index 9db0867..99e1cab 100644
--- a/easylogger/plugins/file/elog_file.c
+++ b/easylogger/plugins/file/elog_file.c
@@ -31,6 +31,8 @@
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
 
 #include <file/elog_file.h>
 #include <file/elog_file_cfg.h>
@@ -53,6 +55,7 @@ ElogErrCode elog_file_init(void)
 
     cfg.name = ELOG_FILE_NAME;
     cfg.max_size = ELOG_FILE_MAX_SIZE;
+    cfg.max_rotate = ELOG_FILE_MAX_ROTATE;
 
     elog_file_config(&cfg);
 
@@ -61,6 +64,52 @@ __exit:
     return result;
 }
 
+/*
+ * rotate the log file xxx.log.n-1 => xxx.log.n, and xxx.log => xxx.log.0
+ *
+ * it will return true when rotate successfully
+ */
+static bool elog_file_rotate(void)
+{
+#define SUFFIX_LEN                     10
+    /* mv xxx.log.n-1 => xxx.log.n, and xxx.log => xxx.log.0 */
+    size_t base = strlen(local_cfg.name);
+    char *oldpath = NULL, *newpath = NULL;
+    int n;
+    FILE *fp_bak = fp;
+
+    oldpath = (char *) malloc(base + SUFFIX_LEN);
+    newpath = (char *) malloc(base + SUFFIX_LEN);
+
+    if (oldpath == NULL || newpath == NULL) {
+        return false;
+    }
+
+    memcpy(oldpath, local_cfg.name, base);
+    memcpy(newpath, local_cfg.name, base);
+
+    for (n = local_cfg.max_rotate - 1; n >= 0; --n) {
+        snprintf(oldpath + base, SUFFIX_LEN, n ? ".%d" : "", n - 1);
+        snprintf(newpath + base, SUFFIX_LEN, ".%d", n);
+        rename(oldpath, newpath);
+    }
+    free(oldpath);
+    free(newpath);
+
+    fp = fopen(local_cfg.name, "a+");
+    if (fp) {
+        if (fp_bak) {
+            fclose(fp_bak);
+        }
+        fd = fileno(fp);
+        return true;
+    } else {
+        fp = fp_bak;
+        fd = -1;
+        return false;
+    }
+}
+
 void elog_file_write(const char *log, size_t size)
 {
     ELOG_ASSERT(init_ok);
@@ -68,13 +117,20 @@ void elog_file_write(const char *log, size_t size)
     struct stat statbuf;
 
     statbuf.st_size = 0;
-    fstat(fd, &statbuf);
-
-    if (unlikely(statbuf.st_size > local_cfg.max_size))
-        return;
 
     elog_file_port_lock();
 
+    fstat(fd, &statbuf);
+
+    if (unlikely(statbuf.st_size > local_cfg.max_size)) {
+        /* rotate the log file */
+        if (local_cfg.max_rotate <= 0 || !elog_file_rotate()) {
+            /* not enabled rotate or rotate failed */
+            elog_file_port_unlock();
+            return;
+        }
+    }
+
     fwrite(log, size, 1, fp);
 
 #ifdef ELOG_FILE_FLUSH_CAHCE_ENABLE
@@ -103,6 +159,7 @@ void elog_file_config(ElogFileCfg *cfg)
 
     local_cfg.name = cfg->name;
     local_cfg.max_size = cfg->max_size;
+    local_cfg.max_rotate = cfg->max_rotate;
 
     fp = fopen(local_cfg.name, "a+");
     if (fp)
diff --git a/easylogger/plugins/file/elog_file.h b/easylogger/plugins/file/elog_file.h
index 03c9fdc..11df802 100644
--- a/easylogger/plugins/file/elog_file.h
+++ b/easylogger/plugins/file/elog_file.h
@@ -49,6 +49,7 @@ extern "C" {
 typedef struct {
     char *name;              /* file name */
     size_t max_size;         /* file max size */
+    int max_rotate;          /* max rotate file count */
 } ElogFileCfg;
 
 /* elog_file.c */
diff --git a/easylogger/plugins/file/elog_file_cfg.h b/easylogger/plugins/file/elog_file_cfg.h
index c1d6973..2454ef8 100644
--- a/easylogger/plugins/file/elog_file_cfg.h
+++ b/easylogger/plugins/file/elog_file_cfg.h
@@ -35,4 +35,7 @@
 /* EasyLogger file log plugin's using file max size */
 #define ELOG_FILE_MAX_SIZE             /* @note you must define it for a value */
 
+/* EasyLogger file log plugin's using max rotate file count */
+#define ELOG_FILE_MAX_ROTATE           /* @note you must define it for a value */
+
 #endif /* _ELOG_FILE_CFG_H_ */
diff --git a/easylogger/src/elog.c b/easylogger/src/elog.c
index f5b1583..945072e 100644
--- a/easylogger/src/elog.c
+++ b/easylogger/src/elog.c
@@ -699,7 +699,7 @@ void elog_hexdump(const char *name, uint8_t width, uint8_t *buf, uint16_t size)
 
     for (i = 0; i < size; i += width) {
         /* package header */
-        fmt_result = snprintf(log_buf, ELOG_LINE_BUF_SIZE, "D/HEX %s: %04X-%04X: ", name, i, i + width);
+        fmt_result = snprintf(log_buf, ELOG_LINE_BUF_SIZE, "D/HEX %s: %04X-%04X: ", name, i, i + width - 1);
         /* calculate log length */
         if ((fmt_result > -1) && (fmt_result <= ELOG_LINE_BUF_SIZE)) {
             log_len = fmt_result;
diff --git a/easylogger/src/elog_async.c b/easylogger/src/elog_async.c
index 6df5f3a..cade4bf 100644
--- a/easylogger/src/elog_async.c
+++ b/easylogger/src/elog_async.c
@@ -283,8 +283,6 @@ static void *async_output(void *arg) {
     size_t get_log_size = 0;
     static char poll_get_buf[ELOG_ASYNC_POLL_GET_LOG_BUF_SIZE];
 
-    ELOG_ASSERT(init_ok);
-
     while(true) {
         /* waiting log */
         sem_wait(&output_notice);