diff --git a/include/utils/logger.h b/include/utils/logger.h
index 59ca40f..eb2fffd 100644
--- a/include/utils/logger.h
+++ b/include/utils/logger.h
@@ -18,7 +18,8 @@ enum {
 #define log_fatal(...) log_printf(LOG_FATAL, __VA_ARGS__)
 
 extern int LOG_LEVEL;
-void log_perror(char *prefix);
+//void log_perror(char *prefix);
+void log_perror(const char *fmt, ...);
 void log_printf(int level, const char *fmt, ...);
 
 #endif
diff --git a/include/utils/process.h b/include/utils/process.h
index b979ead..db2a08c 100644
--- a/include/utils/process.h
+++ b/include/utils/process.h
@@ -6,6 +6,7 @@ typedef struct {
     char **cmd;
     char **env;
     char *cwd;
+    int8_t is_group; // bool value
 } process;
 
 void process_list_run();
@@ -14,4 +15,7 @@ void process_list_append(process *proc);
 void process_add_arg(process *proc, const char *arg);
 process* process_init(const char *caption, const char *bin);
 
+#include <unistd.h>
+pid_t process_exec(process *proc);
+
 #endif
diff --git a/src/cleardns.c b/src/cleardns.c
index 45034b7..d65a561 100644
--- a/src/cleardns.c
+++ b/src/cleardns.c
@@ -1,6 +1,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/wait.h>
 #include "loader.h"
 #include "logger.h"
 #include "constant.h"
@@ -51,20 +52,37 @@ int main(int argc, char *argv[]) { // ClearDNS server
 
     char *config_file = init(argc, argv);
 
+    LOG_LEVEL = LOG_DEBUG;
     log_info("ClearDNS server start (%s)", VERSION);
 
-    create_folder(WORK_DIR);
+//    process *test = process_init("TEST", "lls");
+    process *test = process_init("TEST", "ls");
 
-    load_config(config_file);
-    free(config_file);
+    process_add_arg(test, "-al");
 
-    process_list_init();
-    process_list_append(dnsproxy_load("Domestic", loader.domestic, "domestic.json"));
-    process_list_append(dnsproxy_load("Foreign", loader.foreign, "foreign.json"));
-    process_list_append(overture_load(loader.diverter, "overture.json"));
-    if (loader.filter != NULL) {
-        process_list_append(adguard_load(loader.filter, ADGUARD_DIR));
-    }
+//    test->cwd = "/etc/cleardns/fuck";
+
+    int pid = process_exec(test);
+
+    log_info("PID = %d", pid);
+
+    int status;
+    wait(&status);
+
+    return 0;
+
+    create_folder(WORK_DIR);
+
+//    load_config(config_file);
+//    free(config_file);
+//
+//    process_list_init();
+//    process_list_append(dnsproxy_load("Domestic", loader.domestic, "domestic.json"));
+//    process_list_append(dnsproxy_load("Foreign", loader.foreign, "foreign.json"));
+//    process_list_append(overture_load(loader.diverter, "overture.json"));
+//    if (loader.filter != NULL) {
+//        process_list_append(adguard_load(loader.filter, ADGUARD_DIR));
+//    }
 
     // TODO: running custom script
 
diff --git a/src/utils/logger.c b/src/utils/logger.c
index 121132f..944153f 100644
--- a/src/utils/logger.c
+++ b/src/utils/logger.c
@@ -51,9 +51,21 @@ void log_printf(int level, const char *fmt, ...) {
     }
 }
 
-void log_perror(char *prefix) {
+//void log_perror(char *prefix) {
+//    fprint_prefix();
+//    fprintf(stderr, " %s%s\x1b[0m ", log_color[LOG_ERROR], log_string[LOG_ERROR]);
+//    fflush(stderr);
+//    perror(prefix);
+//}
+
+// TODO: update perror logger
+
+void log_perror(const char *fmt, ...) {
+    va_list ap;
+    va_start(ap, fmt);
     fprint_prefix();
     fprintf(stderr, " %s%s\x1b[0m ", log_color[LOG_ERROR], log_string[LOG_ERROR]);
+    vfprintf(stderr, fmt, ap); // output log content
     fflush(stderr);
-    perror(prefix);
+    perror("");
 }
diff --git a/src/utils/process.c b/src/utils/process.c
index 31bc46e..e1496a2 100644
--- a/src/utils/process.c
+++ b/src/utils/process.c
@@ -1,4 +1,9 @@
 #include <stdlib.h>
+#include <unistd.h>
+#include <sys/wait.h>
+#include <sys/types.h>
+#include <sys/prctl.h>
+#include <stdio.h>
 #include "sundry.h"
 #include "process.h"
 #include "constant.h"
@@ -13,6 +18,7 @@ process* process_init(const char *caption, const char *bin) { // init process st
     proc->cmd = string_list_append(string_list_init(), bin); // argv[0] normally be process file name
     proc->env = string_list_init(); // empty environment variable
     proc->cwd = WORK_DIR; // current working directory
+    proc->is_group = FALSE; // create new process group
     return proc;
 }
 
@@ -39,3 +45,51 @@ void process_list_run() {
         log_warn("proc -> %s", (*p)->name);
     }
 }
+
+void server_exit() {
+    // TODO: kill subprocess and exit cleardns
+}
+
+
+void process_dump(process *proc) {
+    char *process_cmd = string_list_dump(proc->cmd);
+    char *process_env = string_list_dump(proc->env);
+    log_debug("%s cwd -> %s", proc->name, proc->cwd);
+    log_debug("%s command -> %s", proc->name, process_cmd);
+    log_debug("%s env variable -> %s", proc->name, process_env);
+    log_debug("%s new group -> %s", proc->name, show_bool(proc->is_group));
+    free(process_env);
+    free(process_cmd);
+}
+
+pid_t process_exec(process *proc) {
+    pid_t pid;
+
+    process_dump(proc);
+
+    if ((pid = fork()) < 0) { // fork error
+        log_perror("Fork error");
+        server_exit();
+    } else if (pid == 0) { // child process
+        // TODO: new process group
+
+        if (proc->is_group) {
+            setpgrp(); // new process group
+        }
+
+        if (chdir(proc->cwd)) { // change working directory
+            log_perror("%s with invalid cwd `%s` -> ", proc->name, proc->cwd);
+            exit(2);
+        }
+
+        prctl(PR_SET_PDEATHSIG, SIGKILL); // child process die with father process
+        if (execvpe(*(proc->cmd), proc->cmd, proc->env) < 0) {
+            log_perror("%s exec error -> ", proc->name);
+            exit(1);
+        }
+    }
+
+    return pid;
+
+}
+