diff --git a/source/mycss/an_plus_b.c b/source/mycss/an_plus_b.c
index 5409b29..bd57d5d 100644
--- a/source/mycss/an_plus_b.c
+++ b/source/mycss/an_plus_b.c
@@ -96,7 +96,7 @@ void mycss_an_plus_b_serialization(mycss_an_plus_b_entry_t* anb_entry, mycss_cal
     char data[512];
     
     if(anb_entry->a != 0) {
-        int len = snprintf(data, 512, "%ld", anb_entry->a);
+        int len = mycore_snprintf(data, 512, "%ld", anb_entry->a);
         
         if(len > 0)
             callback(data, (size_t)len, context);
@@ -108,7 +108,7 @@ void mycss_an_plus_b_serialization(mycss_an_plus_b_entry_t* anb_entry, mycss_cal
         if(anb_entry->b >= 0)
             callback("+", 1, context);
         
-        int len = snprintf(data, 512, "%ld", anb_entry->b);
+        int len = mycore_snprintf(data, 512, "%ld", anb_entry->b);
         
         if(len > 0)
             callback(data, (size_t)len, context);
diff --git a/source/mycss/namespace/serialization.c b/source/mycss/namespace/serialization.c
index 1dc60d1..6b76ff4 100644
--- a/source/mycss/namespace/serialization.c
+++ b/source/mycss/namespace/serialization.c
@@ -49,7 +49,7 @@ void mycss_namespace_serialization_entry(mycss_namespace_t* ns, mycss_namespace_
         callback(ns_entry->name->data, ns_entry->name->length, context);
     }
     else if(ns_entry->ns_id == MyHTML_NAMESPACE_ANY)
-        return; //fprintf(fh, "*");
+        return; //mycore_fprintf(fh, "*");
     else if(ns_entry->ns_id == MyHTML_NAMESPACE_UNDEF) {
         /* some print */
     }
diff --git a/source/mycss/selectors/serialization.c b/source/mycss/selectors/serialization.c
index 418a2be..080c5e2 100644
--- a/source/mycss/selectors/serialization.c
+++ b/source/mycss/selectors/serialization.c
@@ -28,7 +28,7 @@ void mycss_selectors_serialization_chain(mycss_selectors_t* selectors, mycss_sel
         if(selector->combinator == MyCSS_SELECTORS_COMBINATOR_DESCENDANT)
             callback(" ", 1, context);
         else if(selector->combinator == MyCSS_SELECTORS_COMBINATOR_UNDEF) {
-            /* fprintf(fh, "") */
+            /* mycore_fprintf(fh, "") */
         }
         else {
             callback(" ", 1, context);
diff --git a/source/mycss/values/serialization.c b/source/mycss/values/serialization.c
index 60ad72d..7fcd14d 100644
--- a/source/mycss/values/serialization.c
+++ b/source/mycss/values/serialization.c
@@ -42,11 +42,11 @@ void mycss_values_serialization_number(mycss_values_number_t* value, mycss_callb
     char buff[512];
     
     if(value->is_float) {
-        int len = snprintf(buff, 512, "%0.4f", value->f);
+        int len = mycore_snprintf(buff, 512, "%0.4f", value->f);
         mycss_values_serialization_to_callback(buff, len, callback, context);
     }
     else {
-        int len = snprintf(buff, 512, "%d", value->i);
+        int len = mycore_snprintf(buff, 512, "%d", value->i);
         mycss_values_serialization_to_callback(buff, len, callback, context);
     }
 }
@@ -59,11 +59,11 @@ void mycss_values_serialization_length(mycss_values_length_t* value, mycss_callb
     char buff[512];
     
     if(value->is_float) {
-        int len = snprintf(buff, 512, "%0.4f", value->f);
+        int len = mycore_snprintf(buff, 512, "%0.4f", value->f);
         mycss_values_serialization_to_callback(buff, len, callback, context);
     }
     else {
-        int len = snprintf(buff, 512, "%d", value->i);
+        int len = mycore_snprintf(buff, 512, "%d", value->i);
         mycss_values_serialization_to_callback(buff, len, callback, context);
     }
     
@@ -81,11 +81,11 @@ void mycss_values_serialization_angle(mycss_values_angle_t* value, mycss_callbac
     char buff[512];
     
     if(value->is_float) {
-        int len = snprintf(buff, 512, "%0.4f", value->f);
+        int len = mycore_snprintf(buff, 512, "%0.4f", value->f);
         mycss_values_serialization_to_callback(buff, len, callback, context);
     }
     else {
-        int len = snprintf(buff, 512, "%d", value->i);
+        int len = mycore_snprintf(buff, 512, "%d", value->i);
         mycss_values_serialization_to_callback(buff, len, callback, context);
     }
     
@@ -103,11 +103,11 @@ void mycss_values_serialization_resolution(mycss_values_resolution_t* value, myc
     char buff[512];
     
     if(value->is_float) {
-        int len = snprintf(buff, 512, "%0.4f", value->f);
+        int len = mycore_snprintf(buff, 512, "%0.4f", value->f);
         mycss_values_serialization_to_callback(buff, len, callback, context);
     }
     else {
-        int len = snprintf(buff, 512, "%d", value->i);
+        int len = mycore_snprintf(buff, 512, "%d", value->i);
         mycss_values_serialization_to_callback(buff, len, callback, context);
     }
     
@@ -125,11 +125,11 @@ void mycss_values_serialization_percentage(mycss_values_percentage_t* value, myc
     char buff[512];
     
     if(value->is_float) {
-        int len = snprintf(buff, 512, "%0.4f%%", value->f);
+        int len = mycore_snprintf(buff, 512, "%0.4f%%", value->f);
         mycss_values_serialization_to_callback(buff, len, callback, context);
     }
     else {
-        int len = snprintf(buff, 512, "%d%%", value->i);
+        int len = mycore_snprintf(buff, 512, "%d%%", value->i);
         mycss_values_serialization_to_callback(buff, len, callback, context);
     }
 }
diff --git a/source/myfont/myfont.c b/source/myfont/myfont.c
index 1a91b05..a6b4be6 100644
--- a/source/myfont/myfont.c
+++ b/source/myfont/myfont.c
@@ -304,7 +304,7 @@ void myfont_font_print_exists_table(myfont_font_t *mf, FILE *file)
     for(i = 0; i < MyFONT_TKEY_LAST_KEY; i++)
     { 
         if(mf->cache.tables_offset[i]) {
-            fprintf(file, "%s = %u\n", myfont_table_name[i], mf->cache.tables_offset[i]);
+            mycore_fprintf(file, "%s = %u\n", myfont_table_name[i], mf->cache.tables_offset[i]);
         }
     }
 }
diff --git a/source/myhtml/tag.c b/source/myhtml/tag.c
index 7a761f9..55de2f3 100755
--- a/source/myhtml/tag.c
+++ b/source/myhtml/tag.c
@@ -150,14 +150,14 @@ void myhtml_tag_print(myhtml_tag_t* tags, FILE* fh)
     {
         const myhtml_tag_context_t *ctx = myhtml_tag_get_by_id(tags, i);
         
-        fprintf(fh, "<%s id=\"" MyCORE_FMT_Z "\">\n", ctx->name, i);
+        mycore_fprintf(fh, "<%s id=\"" MyCORE_FMT_Z "\">\n", ctx->name, i);
     }
     
     for(i = (MyHTML_TAG_LAST_ENTRY + 1); i < tags->tags_count; i++)
     {
         const myhtml_tag_context_t *ctx = myhtml_tag_get_by_id(tags, i);
         
-        fprintf(fh, "<%s id=\"" MyCORE_FMT_Z "\">\n", ctx->name, i);
+        mycore_fprintf(fh, "<%s id=\"" MyCORE_FMT_Z "\">\n", ctx->name, i);
     }
 }
 
diff --git a/source/myhtml/token.c b/source/myhtml/token.c
index db0d911..561ecac 100644
--- a/source/myhtml/token.c
+++ b/source/myhtml/token.c
@@ -870,21 +870,21 @@ void myhtml_token_set_replacement_character_for_null_token(myhtml_tree_t* tree,
 void myhtml_token_print_param_by_idx(myhtml_tree_t* myhtml_tree, myhtml_token_node_t* node, FILE* out)
 {
     if(node->type & MyHTML_TOKEN_TYPE_CLOSE) {
-        fprintf(out, "</");
+        mycore_fprintf(out, "</");
     }
     else {
-        fprintf(out, "<");
+        mycore_fprintf(out, "<");
     }
     
-    fprintf(out, "tag_id=" MyCORE_FMT_Z "; body_begin=" MyCORE_FMT_Z "; body_length=" MyCORE_FMT_Z "; attr_first=0x%p; attr_last=0x%p",
+    mycore_fprintf(out, "tag_id=" MyCORE_FMT_Z "; body_begin=" MyCORE_FMT_Z "; body_length=" MyCORE_FMT_Z "; attr_first=0x%p; attr_last=0x%p",
             node->tag_id, node->raw_begin, node->raw_length,
             node->attr_first, node->attr_last);
     
     if(node->type & MyHTML_TOKEN_TYPE_CLOSE_SELF) {
-        fprintf(out, " />\n");
+        mycore_fprintf(out, " />\n");
     }
     else {
-        fprintf(out, ">\n");
+        mycore_fprintf(out, ">\n");
     }
 }
 
@@ -896,31 +896,31 @@ void myhtml_token_print_by_idx(myhtml_tree_t* tree, myhtml_token_node_t* node, F
        node->tag_id == MyHTML_TAG__COMMENT)
     {
         if(node->str.length) {
-            fprintf(out, "%.*s: %.*s\n", (int)ctx->name_length, ctx->name,
+            mycore_fprintf(out, "%.*s: %.*s\n", (int)ctx->name_length, ctx->name,
                     (int)node->str.length, node->str.data);
         }
         else {
-            fprintf(out, "%.*s is empty\n", (int)ctx->name_length, ctx->name);
+            mycore_fprintf(out, "%.*s is empty\n", (int)ctx->name_length, ctx->name);
         }
     }
     else
     {
         if(node->type & MyHTML_TOKEN_TYPE_CLOSE) {
-            fprintf(out, "</");
+            mycore_fprintf(out, "</");
         }
         else {
-            fprintf(out, "<");
+            mycore_fprintf(out, "<");
         }
         
-        fprintf(out, "%.*s tagid=\"" MyCORE_FMT_Z "\"", (int)ctx->name_length, ctx->name, node->tag_id);
+        mycore_fprintf(out, "%.*s tagid=\"" MyCORE_FMT_Z "\"", (int)ctx->name_length, ctx->name, node->tag_id);
         
         myhtml_token_print_attr(tree, node, out);
         
         if(node->type & MyHTML_TOKEN_TYPE_CLOSE_SELF) {
-            fprintf(out, " />\n");
+            mycore_fprintf(out, " />\n");
         }
         else {
-            fprintf(out, ">\n");
+            mycore_fprintf(out, ">\n");
         }
     }
 }
@@ -931,34 +931,34 @@ void myhtml_token_print_attr(myhtml_tree_t* tree, myhtml_token_node_t* node, FIL
     
     while(attr)
     {
-        fprintf(out, " %s", attr->key.data);
+        mycore_fprintf(out, " %s", attr->key.data);
         
         if(attr->ns != MyHTML_NAMESPACE_HTML)
         {
             switch (attr->ns) {
                 case MyHTML_NAMESPACE_SVG:
-                    fprintf(out, ":svg");
+                    mycore_fprintf(out, ":svg");
                     break;
                 case MyHTML_NAMESPACE_MATHML:
-                    fprintf(out, ":math");
+                    mycore_fprintf(out, ":math");
                     break;
                 case MyHTML_NAMESPACE_XLINK:
-                    fprintf(out, ":xlink");
+                    mycore_fprintf(out, ":xlink");
                     break;
                 case MyHTML_NAMESPACE_XML:
-                    fprintf(out, ":xml");
+                    mycore_fprintf(out, ":xml");
                     break;
                 case MyHTML_NAMESPACE_XMLNS:
-                    fprintf(out, ":xmlns");
+                    mycore_fprintf(out, ":xmlns");
                     break;
                 default:
-                    fprintf(out, ":UNDEF");
+                    mycore_fprintf(out, ":UNDEF");
                     break;
             }
         }
         
         if(attr->value.length) {
-            fprintf(out, "=\"%s\"", attr->value.data);
+            mycore_fprintf(out, "=\"%s\"", attr->value.data);
         }
         
         attr = attr->next;
diff --git a/source/myhtml/tree.c b/source/myhtml/tree.c
index f39835d..79eef24 100644
--- a/source/myhtml/tree.c
+++ b/source/myhtml/tree.c
@@ -1681,7 +1681,7 @@ bool myhtml_tree_adoption_agency_algorithm(myhtml_tree_t* tree, myhtml_token_nod
         
         // step 8
         //if(afe_last != list[i])
-        //    fprintf(stderr, "oh");
+        //    mycore_fprintf(stderr, "oh");
         
         // step 9
         myhtml_tree_node_t* current_node = myhtml_tree_current_node(tree);
@@ -1763,7 +1763,7 @@ bool myhtml_tree_adoption_agency_algorithm(myhtml_tree_t* tree, myhtml_token_nod
             if(node_index > 0)
                 node_index--;
             else {
-                fprintf(stderr, "ERROR: adoption agency algorithm; decrement node_index, node_index is null");
+                mycore_fprintf(stderr, "ERROR: adoption agency algorithm; decrement node_index, node_index is null");
                 return false;
             }
             
@@ -2161,54 +2161,54 @@ void myhtml_tree_print_node(myhtml_tree_t* tree, myhtml_tree_node_t* node, FILE*
        node->tag_id == MyHTML_TAG__COMMENT)
     {
         if(node->token)
-            fprintf(out, "<%.*s>: %.*s\n", (int)ctx->name_length, ctx->name,
+            mycore_fprintf(out, "<%.*s>: %.*s\n", (int)ctx->name_length, ctx->name,
                     (int)node->token->str.length, node->token->str.data);
         else
-            fprintf(out, "<%.*s>\n", (int)ctx->name_length, ctx->name);
+            mycore_fprintf(out, "<%.*s>\n", (int)ctx->name_length, ctx->name);
     }
     else if(node->tag_id == MyHTML_TAG__DOCTYPE)
     {
-        fprintf(out, "<!DOCTYPE");
+        mycore_fprintf(out, "<!DOCTYPE");
         
         if(tree->doctype.attr_name) {
-            fprintf(out, " %s", tree->doctype.attr_name);
+            mycore_fprintf(out, " %s", tree->doctype.attr_name);
         }
         
         if(tree->doctype.attr_public) {
-            fprintf(out, " %s", tree->doctype.attr_public);
+            mycore_fprintf(out, " %s", tree->doctype.attr_public);
         }
         
         if(tree->doctype.attr_system) {
-            fprintf(out, " %s", tree->doctype.attr_system);
+            mycore_fprintf(out, " %s", tree->doctype.attr_system);
         }
         
-        fprintf(out, ">\n");
+        mycore_fprintf(out, ">\n");
     }
     else
     {
         if(node->token && node->token->type & MyHTML_TOKEN_TYPE_CLOSE) {
-            fprintf(out, "</%.*s", (int)ctx->name_length, ctx->name);
+            mycore_fprintf(out, "</%.*s", (int)ctx->name_length, ctx->name);
         }
         else {
-            fprintf(out, "<%.*s", (int)ctx->name_length, ctx->name);
+            mycore_fprintf(out, "<%.*s", (int)ctx->name_length, ctx->name);
         }
         
         if(node->ns != MyHTML_NAMESPACE_HTML) {
             switch (node->ns) {
                 case MyHTML_NAMESPACE_SVG:
-                    fprintf(out, ":svg");
+                    mycore_fprintf(out, ":svg");
                     break;
                 case MyHTML_NAMESPACE_MATHML:
-                    fprintf(out, ":math");
+                    mycore_fprintf(out, ":math");
                     break;
                 case MyHTML_NAMESPACE_XLINK:
-                    fprintf(out, ":xlink");
+                    mycore_fprintf(out, ":xlink");
                     break;
                 case MyHTML_NAMESPACE_XML:
-                    fprintf(out, ":xml");
+                    mycore_fprintf(out, ":xml");
                     break;
                 case MyHTML_NAMESPACE_XMLNS:
-                    fprintf(out, ":xmlns");
+                    mycore_fprintf(out, ":xmlns");
                     break;
                 default:
                     break;
@@ -2218,7 +2218,7 @@ void myhtml_tree_print_node(myhtml_tree_t* tree, myhtml_tree_node_t* node, FILE*
         if(node->token)
             myhtml_token_print_attr(tree, node->token, out);
         
-        fprintf(out, ">\n");
+        mycore_fprintf(out, ">\n");
     }
 }
 
@@ -2232,7 +2232,7 @@ void _myhtml_tree_print_node_children(myhtml_tree_t* tree, myhtml_tree_node_t* n
     while(node)
     {
         for(i = 0; i < inc; i++)
-            fprintf(out, "\t");
+            mycore_fprintf(out, "\t");
         
         myhtml_tree_print_node(tree, node, out);
         _myhtml_tree_print_node_children(tree, node->child, out, (inc + 1));
diff --git a/source/myport/posix/mycore/perf.c b/source/myport/posix/mycore/perf.c
index 38c397b..fcb8142 100644
--- a/source/myport/posix/mycore/perf.c
+++ b/source/myport/posix/mycore/perf.c
@@ -250,10 +250,10 @@ uint64_t mycore_hperf_clock(mystatus_t *status)
 
 #define _MyCORE_CHECK_STATUS_AND_PRINT_ERROR \
     if(status == MyCORE_STATUS_PERF_ERROR_COMPILED_WITHOUT_PERF) { \
-        fprintf(fh, "MyCORE: Library compiled without perf source. Please, build library with -DMyCORE_WITH_PERF flag\n"); \
+        mycore_fprintf(fh, "MyCORE: Library compiled without perf source. Please, build library with -DMyCORE_WITH_PERF flag\n"); \
     } \
     else if(status) { \
-        fprintf(fh, "MyCORE: Something wrong! Perhaps, your platform does not support the measurement of performance\n"); \
+        mycore_fprintf(fh, "MyCORE: Something wrong! Perhaps, your platform does not support the measurement of performance\n"); \
     } \
     else
 
@@ -264,7 +264,7 @@ mystatus_t mycore_hperf_print(const char *name, uint64_t x, uint64_t y, FILE *fh
     
     if(freq) {
         _MyCORE_CHECK_STATUS_AND_PRINT_ERROR {
-            fprintf(fh, "%s: %0.5f\n", name, (((float)(y - x) / (float)freq)));
+            mycore_fprintf(fh, "%s: %0.5f\n", name, (((float)(y - x) / (float)freq)));
         }
     }
     
@@ -278,7 +278,7 @@ mystatus_t mycore_hperf_print_by_val(const char *name, uint64_t x, FILE *fh) {
     
     if(freq) {
         _MyCORE_CHECK_STATUS_AND_PRINT_ERROR {
-            fprintf(fh, "%s: %0.5f\n", name, ((float)x / (float)freq));
+            mycore_fprintf(fh, "%s: %0.5f\n", name, ((float)x / (float)freq));
         }
     }