added more codes

miscellaneous/fork.c

@@ -0,0 +1,30 @@
+#include<unistd.h>
+#include<stdio.h>
+#include<sys/wait.h>
+
+int main(int argc, char const *argv[])
+{
+	int pid = fork();
+	int status=0;
+	//int s =wait(&status);
+//	printf("\nIn code with pid = %d, the first status=%d\t%d\n", getpid(),status,s);
+	if(pid==0)
+	{
+		printf("\nMy id :%d\n", getpid());
+		sleep(20);
+		printf("Parent id after sleep:%d\n", getppid());
+		exit(0);
+
+	}	
+	int p=fork();
+	if(p==0)
+		exit(0);
+	int s =wait(&status);
+	printf("\nIn code with pid = %d, the first status=%d\t%d\n", getpid(),status,s);
+	while(s>=0)
+	{	s =wait(&status);
+		printf("\nIn the second part of the code with pid = %d, the first status=%d\t%d\n", getpid(),status,s);
+	}
+
+		return 0;
+}

miscellaneous/test_wait.c

@@ -0,0 +1,40 @@
+#include<sys/types.h>
+#include<sys/wait.h>
+#include<stdio.h>
+#include<stdlib.h>
+int main(void)
+{
+    pid_t   pid;
+    int     status;
+
+    if ((pid = fork()) < 0)
+        printf("fork error");
+    else if (pid == 0)              /* child */
+        exit(7);
+
+    if (wait(&status) != pid)       /* wait for child */
+        printf("\nwait error");
+	printf("\n status=%d\n",status);                /* and print its status */
+
+	status=0;
+    if ((pid = fork()) < 0)
+        printf("\nfork error");
+    else if (pid == 0)              /* child */
+        abort();                    /* generates SIGABRT */
+
+    if (wait(&status) != pid)       /* wait for child */
+        printf("\nwait error");
+    printf("\n status=%d\n",status);                /* and print its status */                 
+status=0;
+    if ((pid = fork()) < 0)
+        printf("\nfork error");
+    else if (pid == 0)              /* child */
+        status /= 0;                /* divide by 0 generates SIGFPE */
+
+    if (wait(&status) != pid)       /* wait for child */
+        printf("\nwait error");
+        	printf("\n status=%d\n",status);                /* and print its status */              
+
+    exit(0);
+}
+

tcp/tcp-iterative/tcp-iterative-client.c

@@ -0,0 +1,36 @@
+#include<stdio.h>
+#include<stdlib.h>
+#include<sys/socket.h>
+#include<arpa/inet.h>
+
+#define SERV_IP "127.0.0.1"
+#define SERV_PORT 9002
+#define MAX 1001
+
+int main()
+{
+	int sockfd;
+	struct sockaddr_in server,client;
+	socklen_t clilen;
+    char sendline[MAX],recvline[MAX];
+	sockfd=socket(AF_INET,SOCK_STREAM,0);
+	int n;
+
+	bzero(&server,sizeof(server));
+	server.sin_family=AF_INET;
+	server.sin_addr.s_addr=inet_addr(SERV_IP);
+	server.sin_port=htons(SERV_PORT);
+
+	bind(sockfd,(struct sockaddr*)&server,sizeof(server));
+
+    connect(sockfd,(struct sockaddr*)&server,sizeof(server));
+	while(fgets(sendline,MAX,stdin)!=NULL)
+	{
+	   write(sockfd,sendline,strlen(sendline));
+	   n=read(sockfd,recvline,MAX);
+	   recvline[n]=0;
+	   fputs(recvline,stdout);
+	   bzero(&recvline,sizeof(recvline));
+	   bzero(&sendline,sizeof(sendline));	
+	}
+}

tcp/tcp-iterative/tcp-iterative-server.c

@@ -0,0 +1,43 @@
+#include<stdio.h>
+#include<sys/socket.h>
+#include<arpa/inet.h>
+#include<string.h>
+
+#define PORT 9002
+#define SERV_IP "127.0.0.1"
+#define MAX 1001
+
+int main()
+{
+	int listenfd,connfd;
+	struct sockaddr_in server,client;
+	socklen_t clilen;
+	char buff[MAX];
+	int n;
+
+    listenfd=socket(AF_INET,SOCK_STREAM,0);
+
+    server.sin_family=AF_INET;
+    server.sin_addr.s_addr=inet_addr(SERV_IP);
+    server.sin_port=htons(PORT);
+
+    bind(listenfd,(struct sockaddr*)&server,sizeof(server));
+
+    listen(listenfd,5);
+
+    for(;;)
+    {   
+    	clilen=sizeof(client);
+    	connfd=accept(listenfd,(struct sockaddr*)&client,&clilen);
+    	while((n=read(connfd,buff,MAX))>0)
+        {
+        	printf("Echoing back\n");
+        	write(connfd,buff,n);
+        }
+        if(n==0)
+          close(connfd);		
+    }
+    close(listenfd);
+
+    return 0;
+}