diff --git a/CMakeLists.txt b/CMakeLists.txt
index 778882f..67cc5ff 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -8,7 +8,7 @@ set(VERSION "${MAJOR_VERSION}.${MID_VERSION}.${MINOR_VERSION}")
 project(${PROJ} VERSION ${VERSION} LANGUAGES C)
 
 # default flags
-set(CMAKE_C_FLAGS "${CFLAGS} -O2")
+set(CMAKE_C_FLAGS "${CFLAGS} -O2 -pedantic-errors")
 set(CMAKE_C_FLAGS_RELEASE "${CMAKE_C_FLAGS}")
 set(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS} -Wextra -Wall -Werror -W")
 set(CMAKE_COLOR_MAKEFILE ON)
diff --git a/locale/ru/LC_MESSAGES/usefull_macros.mo b/locale/ru/LC_MESSAGES/usefull_macros.mo
index b302ff2..e0c1c4b 100644
Binary files a/locale/ru/LC_MESSAGES/usefull_macros.mo and b/locale/ru/LC_MESSAGES/usefull_macros.mo differ
diff --git a/locale/ru/messages.po b/locale/ru/messages.po
index 81f1d4d..f3cd849 100644
--- a/locale/ru/messages.po
+++ b/locale/ru/messages.po
@@ -8,7 +8,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: PACKAGE VERSION\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2025-11-06 15:03+0300\n"
+"POT-Creation-Date: 2026-03-04 09:05+0300\n"
 "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
 "Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
 "Language-Team: LANGUAGE <LL@li.org>\n"
@@ -77,79 +77,79 @@ msgstr ""
 msgid "Can't use multiple args with arg_none!"
 msgstr ""
 
-#: /home/eddy/Docs/SAO/C_diff/snippets_library/parseargs.c:267
+#: /home/eddy/Docs/SAO/C_diff/snippets_library/parseargs.c:268
 #, c-format
 msgid "double long arguments: --%s"
 msgstr ""
 
-#: /home/eddy/Docs/SAO/C_diff/snippets_library/parseargs.c:273
+#: /home/eddy/Docs/SAO/C_diff/snippets_library/parseargs.c:274
 #, c-format
 msgid "double short arguments: -%c"
 msgstr ""
 
-#: /home/eddy/Docs/SAO/C_diff/snippets_library/parseargs.c:343
+#: /home/eddy/Docs/SAO/C_diff/snippets_library/parseargs.c:347
 #, c-format
 msgid "Need argument with %s type\n"
 msgstr ""
 
 #. print only one message
-#: /home/eddy/Docs/SAO/C_diff/snippets_library/parseargs.c:435
+#: /home/eddy/Docs/SAO/C_diff/snippets_library/parseargs.c:439
 msgid "sl_showhelp(): option index out of range"
 msgstr ""
 
-#: /home/eddy/Docs/SAO/C_diff/snippets_library/parseargs.c:441
+#: /home/eddy/Docs/SAO/C_diff/snippets_library/parseargs.c:445
 #, c-format
 msgid "Usage: %s [arguments]\n"
 msgstr ""
 
-#: /home/eddy/Docs/SAO/C_diff/snippets_library/parseargs.c:528
+#: /home/eddy/Docs/SAO/C_diff/snippets_library/parseargs.c:535
 #, c-format
 msgid "Wrong parameter: %s"
 msgstr ""
 
-#: /home/eddy/Docs/SAO/C_diff/snippets_library/parseargs.c:532
+#: /home/eddy/Docs/SAO/C_diff/snippets_library/parseargs.c:539
 #, c-format
 msgid "%s: need argument!"
 msgstr ""
 
-#: /home/eddy/Docs/SAO/C_diff/snippets_library/parseargs.c:536
+#: /home/eddy/Docs/SAO/C_diff/snippets_library/parseargs.c:543
 #, c-format
 msgid "Wrong argument \"%s\" of parameter \"%s\""
 msgstr ""
 
-#: /home/eddy/Docs/SAO/C_diff/snippets_library/socket.c:147
+#: /home/eddy/Docs/SAO/C_diff/snippets_library/socket.c:154
 msgid "Server disconnected"
 msgstr ""
 
-#: /home/eddy/Docs/SAO/C_diff/snippets_library/socket.c:434
+#: /home/eddy/Docs/SAO/C_diff/snippets_library/socket.c:441
 msgid "Can't start server handlers thread"
 msgstr ""
 
-#: /home/eddy/Docs/SAO/C_diff/snippets_library/socket.c:503
+#: /home/eddy/Docs/SAO/C_diff/snippets_library/socket.c:513
 msgid "Limit of connections reached"
 msgstr ""
 
 #. check for RB overflow
 #. -1 - buffer empty (can't be), -2 - buffer overflow
-#: /home/eddy/Docs/SAO/C_diff/snippets_library/socket.c:547
-#: /home/eddy/Docs/SAO/C_diff/snippets_library/socket.c:548
+#: /home/eddy/Docs/SAO/C_diff/snippets_library/socket.c:557
+#: /home/eddy/Docs/SAO/C_diff/snippets_library/socket.c:558
 #, c-format
 msgid "Server thread: ring buffer overflow for fd=%d"
 msgstr ""
 
-#: /home/eddy/Docs/SAO/C_diff/snippets_library/socket.c:562
+#: /home/eddy/Docs/SAO/C_diff/snippets_library/socket.c:572
 #, c-format
 msgid "Server thread: can't write data to ringbuffer: overflow from fd=%d"
 msgstr ""
 
 #. buffer overflow
-#: /home/eddy/Docs/SAO/C_diff/snippets_library/socket.c:574
+#: /home/eddy/Docs/SAO/C_diff/snippets_library/socket.c:584
 #, c-format
 msgid "Server thread: buffer overflow from fd=%d"
 msgstr ""
 
 #. never reached
-#: /home/eddy/Docs/SAO/C_diff/snippets_library/socket.c:664
+#: /home/eddy/Docs/SAO/C_diff/snippets_library/socket.c:681
 #, c-format
 msgid "Unsupported socket type %d"
 msgstr ""
diff --git a/locale/ru/ru.po b/locale/ru/ru.po
index dc054b0..2621218 100644
--- a/locale/ru/ru.po
+++ b/locale/ru/ru.po
@@ -7,7 +7,7 @@
 msgid   ""
 msgstr  "Project-Id-Version: PACKAGE VERSION\n"
         "Report-Msgid-Bugs-To: \n"
-        "POT-Creation-Date: 2025-11-06 14:57+0300\n"
+        "POT-Creation-Date: 2026-03-04 09:01+0300\n"
         "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
         "Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
         "Language-Team: LANGUAGE <LL@li.org>\n"
@@ -76,80 +76,80 @@ msgstr  "
 msgid   "Can't use multiple args with arg_none!"
 msgstr  "Массив параметров не может иметь тип arg_none!"
 
-#: /home/eddy/Docs/SAO/C_diff/snippets_library/parseargs.c:267
+#: /home/eddy/Docs/SAO/C_diff/snippets_library/parseargs.c:268
 #, c-format
 msgid   "double long arguments: --%s"
 msgstr  "дублирующийся длинный параметр: --%s"
 
-#: /home/eddy/Docs/SAO/C_diff/snippets_library/parseargs.c:273
+#: /home/eddy/Docs/SAO/C_diff/snippets_library/parseargs.c:274
 #, c-format
 msgid   "double short arguments: -%c"
 msgstr  "дублирующийся короткий параметр: -%c"
 
-#: /home/eddy/Docs/SAO/C_diff/snippets_library/parseargs.c:343
+#: /home/eddy/Docs/SAO/C_diff/snippets_library/parseargs.c:347
 #, c-format
 msgid   "Need argument with %s type\n"
 msgstr  "Необходим аргумент с типом %s\n"
 
 #. print only one message
-#: /home/eddy/Docs/SAO/C_diff/snippets_library/parseargs.c:435
+#: /home/eddy/Docs/SAO/C_diff/snippets_library/parseargs.c:439
 msgid   "sl_showhelp(): option index out of range"
 msgstr  "sl_showhelp(): индекс опции вне допустимого диапазона"
 
-#: /home/eddy/Docs/SAO/C_diff/snippets_library/parseargs.c:441
+#: /home/eddy/Docs/SAO/C_diff/snippets_library/parseargs.c:445
 #, c-format
 msgid   "Usage: %s [arguments]\n"
 msgstr  "Использование: %s [аргументы]\n"
 
-#: /home/eddy/Docs/SAO/C_diff/snippets_library/parseargs.c:528
+#: /home/eddy/Docs/SAO/C_diff/snippets_library/parseargs.c:535
 #, c-format
 msgid   "Wrong parameter: %s"
 msgstr  "Неправильный параметр: %s"
 
-#: /home/eddy/Docs/SAO/C_diff/snippets_library/parseargs.c:532
+#: /home/eddy/Docs/SAO/C_diff/snippets_library/parseargs.c:539
 #, c-format
 msgid   "%s: need argument!"
 msgstr  "%s: необходим аргумент!"
 
-#: /home/eddy/Docs/SAO/C_diff/snippets_library/parseargs.c:536
+#: /home/eddy/Docs/SAO/C_diff/snippets_library/parseargs.c:543
 #, c-format
 msgid   "Wrong argument \"%s\" of parameter \"%s\""
 msgstr  "Неправильный аргумент \"%s\" параметра \"%s\""
 
-#: /home/eddy/Docs/SAO/C_diff/snippets_library/socket.c:147
+#: /home/eddy/Docs/SAO/C_diff/snippets_library/socket.c:154
 msgid   "Server disconnected"
 msgstr  "Сервер отключен"
 
-#: /home/eddy/Docs/SAO/C_diff/snippets_library/socket.c:434
+#: /home/eddy/Docs/SAO/C_diff/snippets_library/socket.c:441
 msgid   "Can't start server handlers thread"
 msgstr  "Не могу запустить поток-обработчик сервера"
 
-#: /home/eddy/Docs/SAO/C_diff/snippets_library/socket.c:503
+#: /home/eddy/Docs/SAO/C_diff/snippets_library/socket.c:513
 msgid   "Limit of connections reached"
 msgstr  "Достигнут предел соединений"
 
 #. check for RB overflow
 #. -1 - buffer empty (can't be), -2 - buffer overflow
-#: /home/eddy/Docs/SAO/C_diff/snippets_library/socket.c:547
-#: /home/eddy/Docs/SAO/C_diff/snippets_library/socket.c:548
+#: /home/eddy/Docs/SAO/C_diff/snippets_library/socket.c:557
+#: /home/eddy/Docs/SAO/C_diff/snippets_library/socket.c:558
 #, c-format
 msgid   "Server thread: ring buffer overflow for fd=%d"
 msgstr  "Поток сервера: переполнение буфера от fd=%d"
 
-#: /home/eddy/Docs/SAO/C_diff/snippets_library/socket.c:562
+#: /home/eddy/Docs/SAO/C_diff/snippets_library/socket.c:572
 #, c-format
 msgid   "Server thread: can't write data to ringbuffer: overflow from fd=%d"
 msgstr  "Поток сервера: не могу сохранить данные в кольцевом буфере, "
         "переполнение от fd=%d"
 
 #. buffer overflow
-#: /home/eddy/Docs/SAO/C_diff/snippets_library/socket.c:574
+#: /home/eddy/Docs/SAO/C_diff/snippets_library/socket.c:584
 #, c-format
 msgid   "Server thread: buffer overflow from fd=%d"
 msgstr  "Поток сервера: переполнение буфера от fd=%d"
 
 #. never reached
-#: /home/eddy/Docs/SAO/C_diff/snippets_library/socket.c:664
+#: /home/eddy/Docs/SAO/C_diff/snippets_library/socket.c:681
 #, c-format
 msgid   "Unsupported socket type %d"
 msgstr  "Неподдерживаемый тип сокета %d"
diff --git a/parseargs.c b/parseargs.c
index 8e4b7f7..e6d7b10 100644
--- a/parseargs.c
+++ b/parseargs.c
@@ -191,6 +191,18 @@ void *get_aptr(void *paptr, sl_argtype_e type){
     return aptr[i - 1];
 }
 
+static int cmpstringp(const void *p1, const void *p2){
+    if(!p1 || !p2) return 0;
+    const char *str1 = * (char * const *) p1, *str2 = * (char * const *) p2;
+    if(!str1 && !str2) return 0;
+    else if(!str1) return 1;
+    else if(!str2) return -1;
+    return strcmp(str1, str2);
+}
+static int cmpcharp(const void *p1, const void *p2){
+    return (int)(*(char * const)p1 - *(char *const)p2);
+}
+
 /**
  * @brief sl_parseargs_hf - parse arguments with user help funtion
  * @param argc - amount of arguments
@@ -246,17 +258,6 @@ void sl_parseargs_hf(int *argc, char ***argv, sl_option_t *options, void (*helpf
         }
     }
     // sort all lists & check for repeating
-    int cmpstringp(const void *p1, const void *p2){
-        if(!p1 || !p2) return 0;
-        const char *str1 = * (char * const *) p1, *str2 = * (char * const *) p2;
-        if(!str1 && !str2) return 0;
-        else if(!str1) return 1;
-        else if(!str2) return -1;
-        return strcmp(str1, str2);
-    }
-    int cmpcharp(const void *p1, const void *p2){
-        return (int)(*(char * const)p1 - *(char *const)p2);
-    }
     qsort(longlist, optsize, sizeof(char *), cmpstringp);
     qsort(shortlist,optsize, sizeof(char), cmpcharp);
     char *prevl = longlist[0], prevshrt = shortlist[0];
@@ -336,7 +337,10 @@ void sl_parseargs_hf(int *argc, char ***argv, sl_option_t *options, void (*helpf
                 type = "string";
                 break;
             case arg_function:
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wpedantic"
                 result = ((sl_argfn_t)aptr)(optarg);
+#pragma GCC diagnostic pop
                 break;
         }
         if(!result){
@@ -460,6 +464,49 @@ void sl_showhelp(int oindex, sl_option_t *options){
     exit(-1);
 }
 
+static int findsubopt(char *par, sl_suboption_t *so){
+    int idx = 0;
+    if(!par) return -1;
+    while(so[idx].name){
+        if(strcasecmp(par, so[idx].name) == 0) return idx;
+        ++idx;
+    }
+    return -1; // badarg
+}
+static int opt_setarg(sl_suboption_t *so, int idx, char *val){
+    sl_suboption_t *soptr = &so[idx];
+    int result = FALSE;
+    void *aptr = soptr->argptr;
+    switch(soptr->type){
+    default:
+    case arg_none:
+        if(soptr->argptr) *((int*)aptr) += 1; // increment value
+        result = TRUE;
+        break;
+    case arg_int:
+        result = myatoll(aptr, val, arg_int);
+        break;
+    case arg_longlong:
+        result = myatoll(aptr, val, arg_longlong);
+        break;
+    case arg_double:
+        result = myatod(aptr, val, arg_double);
+        break;
+    case arg_float:
+        result = myatod(aptr, val, arg_float);
+        break;
+    case arg_string:
+        result = (*((void**)aptr) = (void*)strdup(val)) != NULL;
+        break;
+    case arg_function:
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wpedantic"
+        result = ((sl_argfn_t)aptr)(val);
+#pragma GCC diagnostic pop
+        break;
+    }
+    return result;
+}
 /**
  * @brief sl_get_suboption - get suboptions from parameter string
  * @param str - parameter string
@@ -467,46 +514,6 @@ void sl_showhelp(int oindex, sl_option_t *options){
  * @return TRUE if all OK
  */
 int sl_get_suboption(char *str, sl_suboption_t *opt){
-    int findsubopt(char *par, sl_suboption_t *so){
-        int idx = 0;
-        if(!par) return -1;
-        while(so[idx].name){
-            if(strcasecmp(par, so[idx].name) == 0) return idx;
-            ++idx;
-        }
-        return -1; // badarg
-    }
-    int opt_setarg(sl_suboption_t *so, int idx, char *val){
-        sl_suboption_t *soptr = &so[idx];
-        int result = FALSE;
-        void *aptr = soptr->argptr;
-        switch(soptr->type){
-            default:
-            case arg_none:
-                if(soptr->argptr) *((int*)aptr) += 1; // increment value
-                result = TRUE;
-            break;
-            case arg_int:
-                result = myatoll(aptr, val, arg_int);
-            break;
-            case arg_longlong:
-                result = myatoll(aptr, val, arg_longlong);
-            break;
-            case arg_double:
-                result = myatod(aptr, val, arg_double);
-            break;
-            case arg_float:
-                result = myatod(aptr, val, arg_float);
-            break;
-            case arg_string:
-                result = (*((void**)aptr) = (void*)strdup(val)) != NULL;
-            break;
-            case arg_function:
-                result = ((sl_argfn_t)aptr)(val);
-            break;
-        }
-        return result;
-    }
     char *tok;
     int ret = FALSE;
     char *tmpbuf;
diff --git a/socket.c b/socket.c
index f1f874c..9b9900a 100644
--- a/socket.c
+++ b/socket.c
@@ -469,7 +469,9 @@ static void *serverthread(void _U_ *d){
     // ZERO - listening server socket
     poll_set[0].fd = sockfd;
     poll_set[0].events = POLLIN;
-    // disconnect client
+    // disconnect client (no way to make this function non-nested)
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wpedantic"
     void disconnect_(sl_sock_t *c, int N){
         DBG("Disconnect client \"%s\" (fd=%d)", c->IP, c->fd);
         if(s->disconnect_handler) s->disconnect_handler(c);
@@ -496,6 +498,7 @@ static void *serverthread(void _U_ *d){
         pthread_mutex_unlock(&c->mutex);
         --nfd;
     }
+#pragma GCC diagnostic pop
     // allocate buffer with size not less than RB size
     size_t bufsize = s->buffer->length; // as RB should be 1 byte less, this is OK
     uint8_t *buf = MALLOC(uint8_t, bufsize);
diff --git a/usefull_macros.h b/usefull_macros.h
index fe99cf9..6172e19 100644
--- a/usefull_macros.h
+++ b/usefull_macros.h
@@ -453,7 +453,7 @@ typedef struct{
     double magick;  // -Inf - to distinguish it from sl_sock_*_t
     int n;          // if n < 0 there was no any number in `key`
 } sl_sock_keyno_t;
-#define SL_SOCK_KEYNO_DEFAULT       (sl_sock_keyno_t){.magick = -INFINITY, .n = -1}
+#define SL_SOCK_KEYNO_DEFAULT       {.magick = -INFINITY, .n = -1}
 void sl_sock_keyno_init(sl_sock_keyno_t*);
 int sl_sock_keyno_check(sl_sock_keyno_t*);