started weather_logger

Daemons/Readme.md

@@ -10,5 +10,5 @@ Different daemons & tools
 - *send_coordinates* - get/send coordinates to 10-micron mount through stellarium daemon (almost deprecated)
 - *teldaemon_astrosib* - work with Astrosib-500 scope equipment by network query
 - *weatherdaemon_multimeteo* - weather daemon for ALL meteo sensors on "Astro-M" complex
-- *weather_database* - make database by data of almost deprecated weather daemons
+- *weather_logger* - make file-based database for all meteo sensors
 - *weather_proxy* - daemon gathering meteo data from `weatherdaemon_multimeteo` and sharing it on localhost over SHM

Daemons/weather_logger/CMakeLists.txt

@@ -0,0 +1,99 @@
+cmake_minimum_required(VERSION 4.0)
+set(PROJ meteologger)
+set(MINOR_VERSION "1")
+set(MID_VERSION "0")
+set(MAJOR_VERSION "0")
+set(VERSION "${MAJOR_VERSION}.${MID_VERSION}.${MINOR_VERSION}")
+
+project(${PROJ} VERSION ${VERSION} LANGUAGES C)
+message("${PROJ} version: ${VERSION}")
+
+option(DEBUG "Compile in debug mode" OFF)
+# option()
+
+# default flags
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -W -Wextra -fPIC")
+set(CMAKE_COLOR_MAKEFILE ON)
+
+# here is one of two variants: all .c in directory or .c files in list
+aux_source_directory(${CMAKE_CURRENT_SOURCE_DIR} SOURCES)
+#list(REMOVE_ITEM SOURCES ${CMAKE_CURRENT_SOURCE_DIR}/<file to remove>)
+#set(SOURCES list_of_c_files)
+
+# we can change file list
+#if(NOT DEFINED something)
+#	set(SOURCES ${SOURCES} one_more_list)
+#	add_definitions(-DSOME_DEFS)
+#endif()
+
+# cmake -DDEBUG=1 -> debugging
+if(DEBUG)
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Og -g3 -ggdb -Werror")
+    add_definitions(-DEBUG)
+    set(CMAKE_BUILD_TYPE DEBUG)
+    set(CMAKE_VERBOSE_MAKEFILE "ON")
+else()
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -O3 -march=native -fdata-sections -ffunction-sections -flto=auto")
+    SET(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -Wl,--gc-sections -flto=auto")
+    set(CMAKE_BUILD_TYPE RELEASE)
+endif()
+
+list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_LIST_DIR}")
+###### pkgconfig ######
+find_package(PkgConfig REQUIRED)
+pkg_check_modules(${PROJ} REQUIRED usefull_macros>=0.3.5)
+
+# external modules like OpenMP:
+#include(FindOpenMP)
+#if(OPENMP_FOUND)
+#	set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${OpenMP_C_FLAGS}")
+#	set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${OpenMP_CXX_FLAGS}")
+#	set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${OpenMP_EXE_LINKER_FLAGS}")
+#endif()
+
+# append data from find_package:
+#list(APPEND ${PROJ}_INCLUDE_DIRS ${<pkg1>_INCLUDE_DIR} ${<pkg2>_INCLUDE_DIR})
+#list(APPEND ${PROJ}_LIBRARIES ${<pkg1>_LIBRARY} ${<pkg2>_LIBRARY})
+#list(APPEND ${${PROJ}_LIBRARY_DIRS}  ${<pkg1>_LIBRARY_DIRS})
+
+# static library
+#set(LIBSRC fd.c weathlib.c)
+#set(LIBHEADER weathlib.h)
+#add_library(${PROJLIB} STATIC ${LIBSRC})
+#set_target_properties(${PROJLIB} PROPERTIES VERSION ${VERSION})
+
+# exe file
+add_executable(${PROJ} ${SOURCES})
+# another exe, depending on some other files
+#add_executable(test_client client.c usefull_macros.c parceargs.c)
+# -I
+include_directories(${${PROJ}_INCLUDE_DIRS})
+# -L
+link_directories(${${PROJ}_LIBRARY_DIRS})
+# -D
+add_definitions(-D_XOPEN_SOURCE=1234 -D_DEFAULT_SOURCE -D_GNU_SOURCE
+        -DPACKAGE_VERSION=\"${VERSION}\" -DMINOR_VERSION=\"${MINOR_VERSION}\" -DMID_VERSION=\"${MID_VERSION}\"
+        -DMAJOR_VERSION=\"${MAJOR_VERSION}\")
+
+###### pthreads ######
+#find_package(Threads REQUIRED)
+#if(THREADS_HAVE_PTHREAD_ARG)
+#  set_property(TARGET ${PROJ} PROPERTY COMPILE_OPTIONS "-pthread")
+#  set_property(TARGET ${PROJ} PROPERTY INTERFACE_COMPILE_OPTIONS "-pthread")
+#endif()
+#if(CMAKE_THREAD_LIBS_INIT)
+#  list(APPEND ${PROJ}_LIBRARIES "${CMAKE_THREAD_LIBS_INIT}")
+#endif()
+
+# target libraries
+target_link_libraries(${PROJ} ${${PROJ}_LIBRARIES} ${CMAKE_DL_LIBS})
+
+# install
+include(GNUInstallDirs)
+install(TARGETS ${PROJ} DESTINATION "bin")
+# Script to be executed at installation time (kind of post-intallation script) to
+# change the right accesses on the installed files
+#INSTALL(SCRIPT inst.cmake)
+
+# subdirs
+#add_subdirectory("plugins")

Daemons/weather_logger/main.c

@@ -0,0 +1,126 @@
+/*
+ * This file is part of the meteologger project.
+ * Copyright 2026 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/prctl.h>
+#include <signal.h>
+#include <stdatomic.h>
+#include <sys/prctl.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <usefull_macros.h>
+
+#include "parseargs.h"
+#include "server.h"
+
+static volatile atomic_int catchsig = 0;
+static pid_t childpid = 0;
+
+void signals(int signo){
+    signal(signo, SIG_IGN);
+    if(catchsig == 0){
+        DBG("superloop not inited");
+        exit(signo);
+    }
+    if(0 == childpid){
+        if(signo == SIGUSR1){ // reload logs after rotating
+            DBG("Got USR1 -> reinit logs");
+            if(!reinit_logs()){
+                stop_server();
+                catchsig = signo;
+            }else signal(signo, signals);
+        }else{ // kill
+            DBG("Got %d -> kill", signo);
+            stop_server();
+            catchsig = signo; // could be 0 or error code / signo
+        }
+    }else{ // throw signal to child
+        if(signo > 0){
+            kill(childpid, signo);
+            LOGMSG("Send received signal %d to child", signo);
+            if(signo != SIGUSR1) catchsig = signo;
+        }else catchsig = signo;
+    }
+}
+
+static void prepare_and_run(glob_pars *G){
+    if(!G) return;
+    sl_socktype_e stype = (G->isunix) ? SOCKT_UNIX : SOCKT_NET;
+    set_reqinterval(G->req_interval);
+    set_nettimeout(G->net_timeout);
+    DBG("Run server");
+    run_server(G->node, stype, G->bddir);
+    DBG("Server died");
+}
+
+int main(int argc, char **argv){
+    sl_init();
+    glob_pars *G = parseargs(&argc, &argv);
+    if(!G) return 1;
+    sl_check4running(NULL, G->pidfile);
+    signal(SIGTERM, signals);
+    signal(SIGINT, signals);
+    signal(SIGQUIT, signals);
+    signal(SIGPIPE, SIG_IGN); // for sockets
+    signal(SIGUSR1, signals); // reload DB
+#ifndef EBUG
+    if(sl_daemonize()) ERRX("Can't daemonize");
+    catchsig = INT_MAX; // now `signals` won't run exit()
+    while(catchsig == INT_MAX){ // guard for dead processes
+        childpid = fork();
+        if(childpid){
+            LOGDBG("create child with PID %d\n", childpid);
+            DBG("Created child with PID %d\n", childpid);
+            pid_t expid = 0;
+            while(catchsig == INT_MAX){
+                expid = waitpid(childpid, NULL, WNOHANG);
+                if(expid < 0){
+                    LOGERR("waitpid() returns -1; exit");
+                    ERRX("waitpid() returns -1; exit");
+                }
+                if(expid == childpid) break;
+                usleep(50000);
+            }
+            WARNX("Child %d died\n", childpid);
+            LOGWARN("Child %d died\n", childpid);
+            sleep(1);
+        }else{
+            prctl(PR_SET_PDEATHSIG, SIGTERM); // send SIGTERM to child when parent dies
+            break; // go out to normal functional
+        }
+    }
+#else
+    // init for DEBUG mode
+    catchsig = INT_MAX;
+#endif
+
+    if(childpid){
+        LOGERR("Main process exits with status %d", catchsig);
+        if(G->pidfile) unlink(G->pidfile);
+    }else{
+        pid_t self = getpid();
+        prepare_and_run(G);
+        if(catchsig == INT_MAX) LOGERR("Child process %d died", self);
+        else LOGERR("Child process %d exits with status %d", self, catchsig);
+        ; // cleanup child here
+#ifdef EBUG
+        if(G->pidfile) unlink(G->pidfile); // unlink PID-file in debug-mode
+#endif
+        usleep(10000); // wait processes to die
+    }
+    return catchsig;
+}

Daemons/weather_logger/meteologger.cflags

@@ -0,0 +1 @@
+-std=c23

Daemons/weather_logger/meteologger.config

@@ -0,0 +1,3 @@
+#define _XOPEN_SOURCE=1234
+#define _DEFAULT_SOURCE
+#define _GNU_SOURCE

Daemons/weather_logger/meteologger.creator

@@ -0,0 +1 @@
+[General]

Daemons/weather_logger/meteologger.cxxflags

@@ -0,0 +1 @@
+-std=c++23

Daemons/weather_logger/meteologger.files

@@ -0,0 +1,6 @@
+CMakeLists.txt
+main.c
+parseargs.c
+parseargs.h
+server.c
+server.h

Daemons/weather_logger/parseargs.c

@@ -0,0 +1,82 @@
+/*
+ * This file is part of the meteologger project.
+ * Copyright 2026 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <string.h>
+#include <usefull_macros.h>
+
+#include "parseargs.h"
+#include "server.h"
+
+#define DEFAULT_PID         "/tmp/meteologger.pid"
+#define MIN_REQ_INTERVAL    (0.2)
+#define MAX_REQ_INTERVAL    (900.)
+#define MIN_NET_TMOUT       (0.1)
+#define MAX_NET_TMOUT       (30.)
+
+static int help;
+
+static glob_pars G = {
+    .pidfile = DEFAULT_PID,
+    .req_interval = 0.5,
+    .net_timeout = 1.,
+};
+
+static sl_option_t opts[] = {
+    {"help",    NO_ARGS,    NULL,   'h',    arg_int,    APTR(&help),        "show this help"},
+    {"node",    NEED_ARG,   NULL,   'n',    arg_string, APTR(&G.node),      "node to connect (host:port or UNIX socket name)"},
+    {"logfile", NEED_ARG,   NULL,   'l',    arg_string, APTR(&G.logfile),   "save logs to file"},
+    {"pidfile", NEED_ARG,   NULL,   'p',    arg_string, APTR(&G.pidfile),   "pidfile name (default: " DEFAULT_PID ")"},
+    {"isunix",  NO_ARGS,    NULL,   'u',    arg_string, APTR(&G.isunix),    "use UNIX socket instead of network"},
+    {"verbose", NO_ARGS,    NULL,   'v',    arg_none,   APTR(&G.verb),      "verbose level (each -v increases)"},
+    {"output",  NEED_ARG,   NULL,   'o',    arg_string, APTR(&G.bddir),     "output directory to store database"},
+    {"interval",NEED_ARG,   NULL,   'i',    arg_double, APTR(&G.req_interval), "weather request interval, s (min: 0.2, max: 900)"},
+    {"timeout", NEED_ARG,   NULL,   't',    arg_double, APTR(&G.net_timeout),"timeout for server's answer, s (min: 0.1, max: 30)"},
+    end_option
+};
+
+glob_pars *parseargs(int *argc, char ***argv){
+    sl_parseargs(argc, argv, opts);
+    if(help){
+        sl_showhelp(-1, opts);
+        return NULL;
+    }
+    if(!G.node) ERRX("Point node to correct");
+    if(!G.bddir) ERRX("Need to know path to save DB");
+    if(!checkDBpath(G.bddir)) ERRX("Can't create logs in %s", G.bddir);
+    // remove trailing '/'
+    int eol = strlen(G.bddir) - 1;
+    DBG("eol=%d", eol);
+    while(eol > 0){
+        DBG("before: %s", G.bddir);
+        if(G.bddir[eol] == '/') G.bddir[eol] = 0;
+        else break;
+        DBG("after: %s", G.bddir);
+        --eol;
+    }
+    if(G.req_interval < MIN_REQ_INTERVAL || G.req_interval > MAX_REQ_INTERVAL)
+        ERRX("Wrong time interval %g, should be in [%g, %g]", G.req_interval, MIN_REQ_INTERVAL, MAX_REQ_INTERVAL);
+    if(G.net_timeout < MIN_NET_TMOUT || G.net_timeout > MAX_NET_TMOUT)
+        ERRX("Wrong network timeout %g, should be in [%g, %g]", G.net_timeout, MIN_NET_TMOUT, MAX_NET_TMOUT);
+    if(G.logfile){
+        sl_loglevel_e lvl = LOGLEVEL_ERR + G.verb;
+        if(lvl >= LOGLEVEL_AMOUNT) lvl = LOGLEVEL_AMOUNT - 1;
+        DBG("Loglevel: %d", lvl);
+        if(!OPENLOG(G.logfile, lvl, 1)) ERRX("Can't open log file %s", G.logfile);
+    }
+    return &G;
+}

Daemons/weather_logger/parseargs.h

@@ -0,0 +1,32 @@
+/*
+ * This file is part of the meteologger project.
+ * Copyright 2026 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+typedef struct{
+    int isunix;             // use UNIX-sockets instead of net
+    int verb;               // verbocity level
+    double req_interval;    // requests interval
+    double net_timeout;     // network timeout
+    char *bddir;            // directory to store all data
+    char *logfile;          // logfile name
+    char *node;             // node of server
+    char *pidfile;          // pidfile name
+} glob_pars;
+
+glob_pars *parseargs(int *argc, char ***argv);

Daemons/weather_logger/server.c

@@ -0,0 +1,413 @@
+/*
+ * This file is part of the meteologger project.
+ * Copyright 2026 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <dirent.h>
+#include <fcntl.h>
+#include <regex.h>
+#include <stdatomic.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include "server.h"
+
+// some "standard" keys from server
+static const char *key_pluginname = "PLUGIN";
+static const char *key_nvalues = "NVALUES";
+
+// sensor's db filename mask: DBpath/weatherXX.log
+static const char *dbfilename_mask = "%s/weather%02d.log";
+// and search regex
+static const char *dbfilename_regex = "weather[[:digit:]]{2}\\.log";
+
+static volatile atomic_bool isrunning = true;
+static volatile atomic_bool logreinit = false;
+static double req_interval = 0.5;   // request interval, s
+static double net_timeout = 1.;     // timeout for server's answer, s
+static char *DBpath = NULL; // path to storage
+
+typedef struct{
+    int fd;             // log file descriptor
+    int idx;            // index of station for requests
+    int nvalues;        // maximal amount of values
+    char path[PATH_MAX];// path to file
+    char *sensname;     // sensor's name
+    char **keys;        // keyword names for header and index in string
+    int *levels;        // array of `weather level` for each keyword
+} senslog_t;
+
+static int Nsensors = 0; // amount of sensors for logging
+static senslog_t *sensors = NULL; // array of files for logging
+
+// commands for communication with server
+typedef enum{
+    CMD_LIST,
+    CMD_GET,
+    CMD_CHKLEVEL,
+    CMD_TIME,
+    CMD_AMOUNT
+} req_commands;
+static const char *commands[CMD_AMOUNT] = {
+    [CMD_LIST] = "list",
+    [CMD_GET] = "get",
+    [CMD_CHKLEVEL] = "chklevel",
+    [CMD_TIME] = "time",
+};
+
+static void delete_senskeys(senslog_t *sensor){
+    if(!sensor) return;
+    for(int j = 0; j < sensor->nvalues; ++j)
+        FREE(sensor->keys[j]);
+    FREE(sensor->keys);
+    sensor->nvalues = 0;
+}
+
+static void sensors_delete(){
+    if(!sensors) return;
+    for(int i = 0; i < Nsensors; ++i){
+        senslog_t *sensor = &sensors[i];
+        delete_senskeys(sensor);
+        FREE(sensor->levels);
+        FREE(sensor->sensname);
+    }
+    FREE(sensors);
+}
+
+// stop server process
+void stop_server(){
+    FNAME();
+    isrunning = false;
+}
+
+// set request interval to this value
+void set_reqinterval(double dt){
+    req_interval = dt; // all checking is in `parseargs.c`
+}
+
+// set network timeout
+void set_nettimeout(double dt){
+    net_timeout = dt;
+}
+
+/**
+ * @brief send_request - send request to server
+ * @param cmd - command index
+ * @return true if OK, false if disconnected
+ */
+static bool send_request(sl_sock_t *sock, const char *req){
+    if(sl_sock_sendstrmessage(sock, req) < 1){
+        LOGERR("Can't send request '%s'", req);
+        return false;
+    }
+    return true;
+}
+
+// reinit logs at start or after rotating
+// @return false if failed
+bool reinit_logs(){
+    FNAME();
+    logreinit = true;
+    return true;
+}
+
+bool checkDBpath(const char *path){
+    struct stat path_stat;
+    if(stat(path, &path_stat)){
+        WARNX("Can't stat() %s", path);
+        return false; // `stat` failed
+    }
+    if(!S_ISDIR(path_stat.st_mode)){
+        WARNX("%s isn't a directory", path);
+        return false; // not a directory
+    }
+    // now check if we can write there
+    if(access(path, W_OK)){
+        WARNX("Can't write to %s", path);
+        return false;
+    }
+    return true;
+}
+
+// find if this sensor already have opened BD;
+// if have, modify sensor->fd and sensor->path, open file for appending and return `true`
+static bool find_old_file(senslog_t *sensor){
+    if(sensor->fd > -1){
+        DBG("found opened file %s with fd %d -> close", sensor->path, sensor->fd);
+        close(sensor->fd);
+        return false; // we need to open new file after logrotating
+    }
+
+    regex_t regex;
+
+    // Compile regex
+    if(regcomp(&regex, dbfilename_regex, REG_EXTENDED | REG_NOSUB) != 0){
+        LOGERR("find_old_file(): error in regcomp(), %s", strerror(errno));
+        WARNX("regcomp()");
+        return false;
+    }
+
+    bool ret = false;
+    DIR *d = opendir(DBpath);
+    if(d){
+        struct dirent *dir;
+        while((dir = readdir(d))){
+            // Check if filename matches regex
+            if(regexec(&regex, dir->d_name, 0, NULL, 0) == 0){
+                DBG("Found: %s", dir->d_name);
+                char fname[PATH_MAX], line[BUFSIZ];
+                snprintf(fname, PATH_MAX, "%s/%s", DBpath, dir->d_name);
+                FILE *fp = fopen(fname, "r");
+                if(!fp){
+                    LOGERR("Cannot open %s for reading: %s", fname, strerror(errno));
+                    DBG("Can't open");
+                    continue;
+                }
+                if(fgets(line, sizeof(line), fp) == NULL){
+                    LOGWARN("Found empty BD file %s - WTF???", fname);
+                    fclose(fp);
+                    continue;
+                }
+                fclose(fp);
+                int len = strlen(line);
+                if(len > 0 && line[len-1] == '\n') line[len-1] = 0; // remove trailing newline
+                if(line[0] != '#' || line[1] != ' '){ // should starts from comment with station's name
+                    LOGWARN("Found broken database file: %s", fname);
+                    continue;
+                }
+                const char *stname = line + 2; // station name from comment
+                if(0 == strcmp(stname, sensor->sensname)){ // good, we found this file!
+                    DBG("Found existant file %s -> append to it", fname);
+                    int newfd = open(fname, O_WRONLY | O_APPEND);
+                    if(newfd < 0){
+                        LOGERR("Can't open existant BD file %s for append, try to create new", fname);
+                        continue;
+                    }
+                    sensor->fd = newfd;
+                    ret = true;
+                    break;
+                }
+            }
+        }
+        closedir(d);
+    }else{
+        LOGERR("Can't open %s: %s", DBpath, strerror(errno));
+    }
+    regfree(&regex);
+    return ret;
+}
+
+// create new database file in `DBpath`
+static bool create_db_file(senslog_t *sensor){
+    FNAME();
+    int num = 0;
+    char path[PATH_MAX];
+    for(; num <= 99; ++num){
+        snprintf(path, PATH_MAX, dbfilename_mask, DBpath, num);
+        DBG("Try to create %s", path);
+        if(access(path, F_OK) != 0) break;   // no such file
+    }
+    if(num > 99){
+        LOGERR("Can't find free filename for station '%s', all numbers from 0 to 99 are busy! WTF???",
+               sensor->sensname);
+        WARNX("No free numbers for sensors");
+        return false;
+    }
+    // create and open write-only
+    int newfd = open(path, O_WRONLY | O_CREAT, 0644);
+    if(newfd < 0){
+        LOGERR("Can't open file %s for station %s: %s", path, sensor->sensname, strerror(errno));
+        WARNX("Can't open %s", path);
+        return false;
+    }
+    DBG("OK, %s opened, try to write header", path);
+    int len = snprintf(path, PATH_MAX, "# %s\n", sensor->sensname);
+    if(write(newfd, path, len) != len){
+        LOGERR("Can't write sensor's name '%s' to file %s: %s", sensor->sensname, path, strerror(errno));
+        WARNX("Can't write header");
+        close(newfd);
+        return false;
+    }
+    DBG("%s now have descriptor %d: %s", sensor->sensname, newfd, path);
+    sensor->fd = newfd;
+    return true;
+}
+
+static bool get_sensor_keys(senslog_t _U_ *sensor, sl_sock_t _U_ *sock){
+    return true;
+}
+
+// prepare BD files and fill `sensors[i].fd` fields; make header in new file or move write pointer to the end of existant
+// `sensors` should be prepared already
+// this function called at start and on any logs reinit
+static bool prepare_files(sl_sock_t *sock){
+    if(!sock || !DBpath || Nsensors < 1) return false;
+    for(int i = 0; i < Nsensors; ++i){
+        senslog_t *sensor = &sensors[i];
+        if(!get_sensor_keys(sensor, sock)) return false;
+        DBG("Check if there's something for sensor[%d]", i);
+        if(!find_old_file(sensor)){ // create new file
+            DBG("Nothing found, try to create new");
+            if(!create_db_file(sensor)){
+                DBG("Oops: can't create");
+                return false;
+            }
+        }
+    }
+    DBG("All ready!");
+    return true;
+}
+
+static bool analyse_list(sl_sock_t *sock){
+    FNAME();
+    char str[BUFSIZ], key[SL_KEY_LEN], value[SL_VAL_LEN];
+    double tlast = sl_dtime();
+    while(sl_dtime() - tlast < net_timeout){
+        ssize_t len = sl_sock_readline(sock, str, BUFSIZ-1);
+        if(len == 0) continue;
+        if(len < 0){
+            WARNX("Seems like server disconnected");
+            LOGWARN("Server disconnected?");
+            sensors_delete();
+            return false;
+        }
+        tlast = sl_dtime();
+        DBG("Got answer: %s", str);
+        if(2 != sl_get_keyval(str, key, value)){
+            LOGWARN("Wrong answer from meteodaemon for 'list' request: %s", str);
+            continue;
+        }
+        DBG("key: '%s', value: '%s'", key, value);
+        int idx;
+        // we don't need `str` now and can use it again
+        if(2 != sscanf(key, "%[^[][%d]", str, &idx)){
+            LOGWARN("Wrong key format: '%s'", key);
+            continue;
+        }
+        DBG("Got key '%s' with idx=%d", str, idx);
+        if(Nsensors <= idx){
+            int oldN = Nsensors;
+            Nsensors = idx + 1;
+            sensors = realloc(sensors, Nsensors * sizeof(senslog_t));
+            if(!sensors){
+                sensors_delete();
+                LOGERR("analyse_list(): error in realloc()");
+                WARNX("analyse_list(): error in realloc()");
+                return false;
+            }
+            bzero(&sensors[oldN], sizeof(senslog_t)*(Nsensors - oldN));
+        }
+        senslog_t *sensor = &sensors[idx];
+        if(0 == strcmp(str, key_pluginname)){ // found plugin name -> fill this field
+            if(sensor->sensname) free(sensor->sensname);
+            sensor->sensname = strdup(value);
+            sensor->idx = idx;
+            sensor->fd = -1; // not inited yet
+            DBG("name[%d]=%s", idx, sensor->sensname);
+        }else if(0 == strcmp(str, key_nvalues)){
+            int nvalues = atoi(value);
+            if(nvalues < 1){
+                LOGWARN("wrong server's responce for sensor[%d] values amount: %d", idx, nvalues);
+                continue;
+            }
+            if(sensor->nvalues) delete_senskeys(sensor);
+            sensor->nvalues = nvalues;
+            DBG("sensor[%d] have %d values", idx, sensor->nvalues);
+            sensor->keys = MALLOC(char*, nvalues); // prepare empty array for keywords
+            sensor->levels = MALLOC(int, nvalues);
+        }
+    }
+    // now check all we got
+    if(Nsensors < 1){
+        LOGWARN("Found 0 sensors in server's answer");
+        WARNX("Found 0 sensors in server's answer");
+        return false;
+    }
+    bool ans = true;
+    for(int i = 0; i < Nsensors; ++i){
+        senslog_t *sensor = &sensors[i];
+        DBG("Check sensor %s with values %d", sensor->sensname, sensor->nvalues);
+        if(sensor->nvalues < 1){
+            LOGWARN("Zero keys for station %s", sensor->sensname);
+            ans = false; break;
+        }
+    }
+    if(ans) ans = prepare_files(sock);
+    if(ans == false) sensors_delete();
+    return ans;
+}
+
+/*for(int i = 0; i < nvalues; ++i){
+                sensor->keys[i] = ;
+            }*/
+
+// prepare DB files at start
+static bool prepare_logfiles(sl_sock_t *sock, const char *path){
+    FNAME();
+    char buf[PATH_MAX];
+    if(DBpath) return false; // already inited??
+    if(!checkDBpath(path)) return false;
+    DBpath = strdup(path);
+    if(!DBpath){
+        WARN("strdup()");
+        return false;
+    }
+    DBG("Store files in %s; send `list` request", DBpath);
+    snprintf(buf, 255, "%s\n", commands[CMD_LIST]);
+    if(!send_request(sock, buf)){
+        WARNX("Can't send inited request");
+        return false;
+    }
+    // now we have an answer: 2*N strings a la "PLUGIN[i]=...\nNVALUES[i]=...\n" ->
+    //     prepare `sensors` and try to find opened files like `sensorXX.log`
+    if(!analyse_list(sock)) return false;
+    return true;
+}
+
+/**
+ * @brief run_server - run main server: send weather requests and store data
+ * @param node - node to connect
+ * @param type - socket type
+ * @param path - directory where to store data logs
+ */
+void run_server(const char *node, sl_socktype_e type, const char *path){
+    if(!node || !path) return;
+    sl_sock_t *sock = sl_sock_run_client(type, node, BUFSIZ);
+    if(!sock){
+        DBG("Can't connect");
+        LOGERR("Can't connect to %s", node);
+        return;
+    }
+    if(!prepare_logfiles(sock, path)) return;
+
+    DBG("Superloop");
+    int errctr = 0;
+    while(isrunning){
+        if(logreinit){
+            if(!prepare_files(sock)) ++errctr;
+            else logreinit = false;
+        }
+        if(errctr > 5){
+            LOGERR("Too much errors -> exit");
+            break;
+        }
+        usleep(1000);
+    }
+    if(sock) sl_sock_delete(&sock);
+    sensors_delete();
+}

Daemons/weather_logger/server.h

@@ -0,0 +1,28 @@
+/*
+ * This file is part of the meteologger project.
+ * Copyright 2026 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include <usefull_macros.h>
+
+bool checkDBpath(const char *path);
+void stop_server();
+void set_reqinterval(double dt);
+void set_nettimeout(double dt);
+void run_server(const char *node, sl_socktype_e type, const char *path);
+bool reinit_logs();