diff --git a/TMP/Practice/sock20.10.23/app_client b/TMP/Practice/sock20.10.23/app_client
new file mode 100755
index 0000000..c647da4
Binary files /dev/null and b/TMP/Practice/sock20.10.23/app_client differ
diff --git a/TMP/Practice/sock20.10.23/app_server b/TMP/Practice/sock20.10.23/app_server
new file mode 100755
index 0000000..f050949
Binary files /dev/null and b/TMP/Practice/sock20.10.23/app_server differ
diff --git a/TMP/Practice/sock20.10.23/c4.c b/TMP/Practice/sock20.10.23/c4.c
index 010362d..c09eab9 100644
--- a/TMP/Practice/sock20.10.23/c4.c
+++ b/TMP/Practice/sock20.10.23/c4.c
@@ -9,8 +9,19 @@
 #include <unistd.h>
 #include <time.h>
 
-#define errExit(msg)       do { perror(msg); _exit(EXIT_FAILURE); } while (0)
-#define SerrExit(s,msg)    do { close(s); perror(msg); _exit(EXIT_FAILURE); } while (0)
+#define errExit(msg)       \
+   do                      \
+   {                       \
+      perror(msg);         \
+      _exit(EXIT_FAILURE); \
+   } while (0)
+#define SerrExit(s, msg)   \
+   do                      \
+   {                       \
+      close(s);            \
+      perror(msg);         \
+      _exit(EXIT_FAILURE); \
+   } while (0)
 
 #define SERVER_PATH "/tmp/unix_sock.server"
 #define CLIENT_PATH "unix_sock.client"
@@ -18,125 +29,146 @@
 #define BUF 128
 #define FINS "exit_s"
 #define FINC "exit_c"
-//#define INFO 
+// #define INFO
 
-int rcvBuffer(int sock_fd){
-      int rcvBufferSize;
-      socklen_t sockOptSize = sizeof(rcvBufferSize);
-      getsockopt(sock_fd, SOL_SOCKET, SO_RCVBUF, &rcvBufferSize, &sockOptSize);
+int rcvBuffer(int sock_fd)
+{
+   int rcvBufferSize;
+   socklen_t sockOptSize = sizeof(rcvBufferSize);
+   getsockopt(sock_fd, SOL_SOCKET, SO_RCVBUF, &rcvBufferSize, &sockOptSize);
 #ifdef INFO
-      printf("initial socket receive buf %d\n", rcvBufferSize);
+   printf("initial socket receive buf %d\n", rcvBufferSize);
 #endif
-      return rcvBufferSize;
+   return rcvBufferSize;
 }
 
-int recvCount(const void *s, int size){
+int recvCount(const void *s, int size)
+{
    register int count;
    register int mark;
    register char *p;
-   p=(char *)s;
+   p = (char *)s;
    count = 0;
    mark = 0;
-   do {
-     if (*p && !(*(p+1))) count++;
+   do
+   {
+      if (*p && !(*(p + 1)))
+         count++;
 #ifdef INFO
-     printf("[%c][%X]\n",*p,*p);
+      printf("[%c][%X]\n", *p, *p);
 #endif
-     p++;
-     mark++;
-   } while (!((*p == '\0') && (*(p+1)=='\0')) && (mark < size));
+      p++;
+      mark++;
+   } while (!((*p == '\0') && (*(p + 1) == '\0')) && (mark < size));
    return count;
 }
 
-int main(int argc,char *argv[]){
+int main(int argc, char *argv[])
+{
 
-    int client_sock, rc, len;
-    struct sockaddr_un server_sockaddr; 
-    struct sockaddr_un client_sockaddr; 
-    char obuf[BUF];
-    char **ibuf;
-    size_t obs=BUF,ibs;
-    char cpath[22];
+   int client_sock, rc, len;
+   struct sockaddr_un server_sockaddr;
+   struct sockaddr_un client_sockaddr;
+   char obuf[BUF];
+   char **ibuf;
+   size_t obs = BUF, ibs;
+   char cpath[22];
 
-    sprintf(cpath,"%d-%s",getpid(),CLIENT_PATH); 
-    len = sizeof(client_sockaddr);
-    memset(&server_sockaddr, 0, sizeof(struct sockaddr_un));
-    memset(&client_sockaddr, 0, sizeof(struct sockaddr_un));
-     
-    client_sock = socket(AF_UNIX, SOCK_STREAM, 0);
-    if (client_sock == -1) {
-        perror("socket");
-        exit(1);
-    }
+   sprintf(cpath, "%d-%s", getpid(), CLIENT_PATH);
+   len = sizeof(client_sockaddr);
+   memset(&server_sockaddr, 0, sizeof(struct sockaddr_un));
+   memset(&client_sockaddr, 0, sizeof(struct sockaddr_un));
 
+   client_sock = socket(AF_UNIX, SOCK_STREAM, 0);
+   if (client_sock == -1)
+   {
+      perror("socket");
+      exit(1);
+   }
 
-    client_sockaddr.sun_family = AF_UNIX;   
-    strcpy(client_sockaddr.sun_path, cpath); 
-    
-    unlink(cpath);
-    rc = bind(client_sock, (struct sockaddr *) &client_sockaddr, len);
-    if (rc == -1) SerrExit(client_sock,"bind");
+   client_sockaddr.sun_family = AF_UNIX;
+   strcpy(client_sockaddr.sun_path, cpath);
 
-    server_sockaddr.sun_family = AF_UNIX;
-    strcpy(server_sockaddr.sun_path, SERVER_PATH);
-    rc = connect(client_sock, (struct sockaddr *) &server_sockaddr, len);
-    if (rc == -1) SerrExit(client_sock,"connect");
-    
-    ibs=rcvBuffer(client_sock);
-    if ((ibuf=(char **)malloc(ibs)) == NULL ) errExit("malloc");
+   unlink(cpath);
+   rc = bind(client_sock, (struct sockaddr *)&client_sockaddr, len);
+   if (rc == -1)
+      SerrExit(client_sock, "bind");
 
-    do {
+   server_sockaddr.sun_family = AF_UNIX;
+   strcpy(server_sockaddr.sun_path, SERVER_PATH);
+   rc = connect(client_sock, (struct sockaddr *)&server_sockaddr, len);
+   if (rc == -1)
+      SerrExit(client_sock, "connect");
+
+   ibs = rcvBuffer(client_sock);
+   if ((ibuf = (char **)malloc(ibs)) == NULL)
+      errExit("malloc");
+
+   do
+   {
       memset(obuf, 0, obs);
-       printf("> ");
-      scanf("%s",obuf);
+      printf("> ");
+      scanf("%s", obuf);
 
       printf("Sending data...\n");
-      rc = send(client_sock, obuf, strlen(obuf)+1, 0);
-      if (rc == -1) {
+      rc = send(client_sock, obuf, strlen(obuf) + 1, 0);
+      if (rc == -1)
+      {
          perror("send");
          close(client_sock);
          exit(1);
-      } else {
-        printf("Data sent!\n");
+      }
+      else
+      {
+         printf("Data sent!\n");
       }
 
       printf("Waiting to recieve data...\n");
       memset(ibuf, 0, ibs);
-      rc = recv(client_sock, ibuf, ibs,0);
-      if (rc == -1) {
+      rc = recv(client_sock, ibuf, ibs, 0);
+      if (rc == -1)
+      {
          perror("recv");
          close(client_sock);
          exit(1);
-      } else {
-        int c = recvCount(ibuf,ibs);
+      }
+      else
+      {
+         int c = recvCount(ibuf, ibs);
 #ifdef INFO
-        char *p = (char *)ibuf;
-        printf("count: %d resieved\n",c);
-        for (int i = 0; i < 32; i++){
-           printf("[%c][%X]",*p,*p);
-           p++;
-        }
-        printf("\n");
+         char *p = (char *)ibuf;
+         printf("count: %d resieved\n", c);
+         for (int i = 0; i < 32; i++)
+         {
+            printf("[%c][%X]", *p, *p);
+            p++;
+         }
+         printf("\n");
 #endif
 #ifndef INFO
-        char p[obs];
-        char *tp = (char *)ibuf;
-//        if ((ibuf=(char **)malloc(ibs)) == NULL ) errExit("malloc");
-        for (int i = 0; i < c; i++){
-           memset(p,0,obs);
-           while (*tp) {strncat(p,tp,1);tp++;}
-           tp++;
-//           printf("DATA RECEIVED [%ld] = %s\n", strlen(ibuf[i]),ibuf[i]);
-           printf("DATA RECEIVED [%ld] = %s\n", strlen(p),p);
-//           printf("DATA RECEIVED [%ld] = %s\n", strlen(p[i]),p[i]);
-        }
+         char p[obs];
+         char *tp = (char *)ibuf;
+         //        if ((ibuf=(char **)malloc(ibs)) == NULL ) errExit("malloc");
+         for (int i = 0; i < c; i++)
+         {
+            memset(p, 0, obs);
+            while (*tp)
+            {
+               strncat(p, tp, 1);
+               tp++;
+            }
+            tp++;
+            //           printf("DATA RECEIVED [%ld] = %s\n", strlen(ibuf[i]),ibuf[i]);
+            printf("DATA RECEIVED [%ld] = %s\n", strlen(p), p);
+            //           printf("DATA RECEIVED [%ld] = %s\n", strlen(p[i]),p[i]);
+         }
 #endif
       }
-      
-    } while (strcmp(obuf,FINC) && strcmp(obuf,FINS));
 
-    close(client_sock);
-    unlink(cpath);
-    
-    return 0;
+   } while (strcmp(obuf, FINC) && strcmp(obuf, FINS));
+
+   close(client_sock);
+   unlink(cpath);
+
+   return 0;
 }
diff --git a/TMP/Practice/sock20.10.23/files/app_client b/TMP/Practice/sock20.10.23/files/app_client
new file mode 100755
index 0000000..c647da4
Binary files /dev/null and b/TMP/Practice/sock20.10.23/files/app_client differ
diff --git a/TMP/Practice/sock20.10.23/files/app_server b/TMP/Practice/sock20.10.23/files/app_server
new file mode 100755
index 0000000..72c8be5
Binary files /dev/null and b/TMP/Practice/sock20.10.23/files/app_server differ
diff --git a/TMP/Practice/sock20.10.23/s4.c b/TMP/Practice/sock20.10.23/s4.c
index 48b2e3f..c4f8b7d 100644
--- a/TMP/Practice/sock20.10.23/s4.c
+++ b/TMP/Practice/sock20.10.23/s4.c
@@ -11,132 +11,162 @@
 #include <sys/wait.h>
 #include <sys/types.h>
 
-#define errExit(msg)    do { perror(msg); _exit(EXIT_FAILURE); } while (0)
+#define errExit(msg)       \
+   do                      \
+   {                       \
+      perror(msg);         \
+      _exit(EXIT_FAILURE); \
+   } while (0)
 
-#define SOCK_PATH  "/tmp/unix_sock.server"
+#define SOCK_PATH "/tmp/unix_sock.server"
 #define DATA "Hello from server"
 #define BUF 128
 #define FINS "exit_s"
 #define FINC "exit_c"
 
-void child_handler(int sig) {
-    pid_t pid;
-    while((pid = waitpid(-1, NULL, WNOHANG)) > 0);
+void child_handler(int sig)
+{
+   pid_t pid;
+   while ((pid = waitpid(-1, NULL, WNOHANG)) > 0)
+      ;
 }
 
-void session(int client_sock, struct sockaddr_un server_sockaddr, struct sockaddr_un client_sockaddr){     
- int rc;
- char inbuf[BUF];
- char outbuf[BUF];
- int bytes_rec = 0;
- size_t bs = BUF;
- socklen_t len;
- pid_t ppid, pid;
+void session(int client_sock, struct sockaddr_un server_sockaddr, struct sockaddr_un client_sockaddr)
+{
+   int rc;
+   char inbuf[BUF];
+   char outbuf[BUF];
+   int bytes_rec = 0;
+   size_t bs = BUF;
+   socklen_t len;
+   pid_t ppid, pid;
 
- ppid=getppid();
- pid=getpid();
+   ppid = getppid();
+   pid = getpid();
 
    len = sizeof(client_sockaddr);
-   rc = getpeername(client_sock, (struct sockaddr *) &client_sockaddr, &len);
-   if (rc == -1){
+   rc = getpeername(client_sock, (struct sockaddr *)&client_sockaddr, &len);
+   if (rc == -1)
+   {
       close(client_sock);
       errExit("getpeer");
-   } else {
+   }
+   else
+   {
       printf("[%d] Client socket filepath: %s\n", pid, client_sockaddr.sun_path);
    }
-   do { 
-     printf("waiting for %s...\n",client_sockaddr.sun_path);
-     memset(inbuf, 0, bs);                
-     bytes_rec = recv(client_sock, inbuf, bs, 0);
-     if (bytes_rec == -1){
-        close(client_sock);
-        errExit("recv");
-     } else {
-      printf("[%s]:  %s\n", client_sockaddr.sun_path, inbuf);
-     }
-    
-     memset(outbuf, 0, bs);
-     strcpy(outbuf, DATA);      
-     printf("Sending data...\n");
-     rc = send(client_sock, outbuf, strlen(outbuf)+1, 0);
-     if (rc == -1) {
-        close(client_sock);
-        errExit("send");
-     } else {
-        printf("Data sent!\n");
-     }
-     if (strcmp(inbuf,FINS) == 0 ) {kill(ppid,SIGTERM);break;}
-   } while (strcmp(inbuf,FINC));
+   do
+   {
+      printf("waiting for %s...\n", client_sockaddr.sun_path);
+      memset(inbuf, 0, bs);
+      bytes_rec = recv(client_sock, inbuf, bs, 0);
+      if (bytes_rec == -1)
+      {
+         close(client_sock);
+         errExit("recv");
+      }
+      else
+      {
+         printf("[%s]:  %s\n", client_sockaddr.sun_path, inbuf);
+      }
+
+      memset(outbuf, 0, bs);
+      strcpy(outbuf, DATA);
+      printf("Sending data...\n");
+      rc = send(client_sock, outbuf, strlen(outbuf) + 1, 0);
+      if (rc == -1)
+      {
+         close(client_sock);
+         errExit("send");
+      }
+      else
+      {
+         printf("Data sent!\n");
+      }
+      if (strcmp(inbuf, FINS) == 0)
+      {
+         kill(ppid, SIGKILL);
+         break;
+      }
+   } while (strcmp(inbuf, FINC));
    memset(outbuf, 0, bs);
-   sprintf(outbuf,"Exit %d\n",pid);      
-   rc = send(client_sock, outbuf, strlen(outbuf)+1, 0);
-   if (rc == -1) {
+   sprintf(outbuf, "Exit %d\n", pid);
+   rc = send(client_sock, outbuf, strlen(outbuf) + 1, 0);
+   if (rc == -1)
+   {
       close(client_sock);
       errExit("send");
-   } 
+   }
    close(client_sock);
    exit(0);
 }
 
-int main(void){
+int main(void)
+{
 
- int server_sock, client_sock, rc;
- socklen_t len;
- struct sockaddr_un server_sockaddr;
- struct sockaddr_un client_sockaddr;     
- int backlog = 10;
- pid_t pid;
+   int server_sock, client_sock, rc;
+   socklen_t len;
+   struct sockaddr_un server_sockaddr;
+   struct sockaddr_un client_sockaddr;
+   int backlog = 10;
+   pid_t pid;
 
- struct sigaction new_act, old_act;
- sigemptyset (&new_act.sa_mask);
- new_act.sa_flags = SA_RESTART;
- new_act.sa_handler = child_handler;
- sigaction (SIGCHLD, &new_act, &old_act);
+   struct sigaction new_act, old_act;
+   sigemptyset(&new_act.sa_mask);
+   new_act.sa_flags = SA_RESTART;
+   new_act.sa_handler = child_handler;
+   sigaction(SIGCHLD, &new_act, &old_act);
 
- len = sizeof(server_sockaddr);
- memset(&server_sockaddr, 0, sizeof(struct sockaddr_un));
- memset(&client_sockaddr, 0, sizeof(struct sockaddr_un));
-    
- server_sock = socket(AF_UNIX, SOCK_STREAM, 0);
- if (server_sock == -1) errExit("socket");
-    
- server_sockaddr.sun_family = AF_UNIX;   
- strcpy(server_sockaddr.sun_path, SOCK_PATH); 
-    
- unlink(SOCK_PATH);
- rc = bind(server_sock, (struct sockaddr *) &server_sockaddr, len);
- if (rc == -1){
-    close(server_sock);
-    errExit("bind");
- }
-    
- rc = listen(server_sock, backlog);
- if (rc == -1){
-    close(server_sock);
-    errExit("listen");
- }
+   len = sizeof(server_sockaddr);
+   memset(&server_sockaddr, 0, sizeof(struct sockaddr_un));
+   memset(&client_sockaddr, 0, sizeof(struct sockaddr_un));
 
- printf("socket listening...\n");
+   server_sock = socket(AF_UNIX, SOCK_STREAM, 0);
+   if (server_sock == -1)
+      errExit("socket");
 
- do {
-   client_sock = accept(server_sock, (struct sockaddr *) &client_sockaddr, &len);
-   if (client_sock == -1){
+   server_sockaddr.sun_family = AF_UNIX;
+   strcpy(server_sockaddr.sun_path, SOCK_PATH);
+
+   unlink(SOCK_PATH);
+   rc = bind(server_sock, (struct sockaddr *)&server_sockaddr, len);
+   if (rc == -1)
+   {
       close(server_sock);
-      close(client_sock);
-      errExit("accept");
+      errExit("bind");
    }
-   if ((pid = fork()) == -1 ) {
-      close(server_sock);
-      close(client_sock);
-      errExit("fork");
-   }
-   if (pid == 0) session(client_sock,server_sockaddr,client_sockaddr);
-   close(client_sock);
- } while (1);
-   
 
- close(server_sock);
- unlink(SOCK_PATH);
-    
- return 0;
+   rc = listen(server_sock, backlog);
+   if (rc == -1)
+   {
+      close(server_sock);
+      errExit("listen");
+   }
+
+   printf("socket listening...\n");
+
+   do
+   {
+      client_sock = accept(server_sock, (struct sockaddr *)&client_sockaddr, &len);
+      if (client_sock == -1)
+      {
+         close(server_sock);
+         close(client_sock);
+         errExit("accept");
+      }
+      if ((pid = fork()) == -1)
+      {
+         close(server_sock);
+         close(client_sock);
+         errExit("fork");
+      }
+      if (pid == 0)
+         session(client_sock, server_sockaddr, client_sockaddr);
+      close(client_sock);
+   } while (1);
+
+   close(server_sock);
+   unlink(SOCK_PATH);
+
+   return 0;
 }