TCP and UDP in C

http://pastebin.com/JCJ2U4xY

code=yes
#programming
#c

/*
 ============================================================================
 Name        : TCPServer.c
 Author      : www.facebook.com/unix4u
 Version     :
 Copyright   : LGPL
 Description : TCP-SERVER IN  C, Ansi-style
 ============================================================================
 */

#include <stdio.h>
#include <stdlib.h>
#include <netinet/in.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <errno.h>
#include <unistd.h>
#include <string.h>
#include <signal.h>

void signalhandler(int signum)
{
	if(SIGTERM==signum)
	{
		printf("See you later bye\n");
		exit(SIGTERM);
	}
}

int main(int argc,char *argv[]) {

	signal(SIGTERM,signalhandler);

	int server_sock_fd,client_sock_fd;
	struct sockaddr_in server_addr;
	char readbuffer[256]="",writebuffer[256]="";

	if(argc<2)
	{
		printf("please run as ./TCPServer <port-no> \n");
		exit(1);
	}

	server_sock_fd=socket(AF_INET,SOCK_STREAM,0);
	perror("Create socket");
	if(errno!=0)
		exit(errno);

	server_addr.sin_family=AF_INET;
	server_addr.sin_addr.s_addr=htonl(INADDR_ANY);
	server_addr.sin_port=htons(atoi(argv[1]));
	bind(server_sock_fd,(struct sockaddr *)&server_addr,sizeof(server_addr));
	perror("Bind");
	if(errno!=0)
	exit(errno);

	listen(server_sock_fd,1);
	perror("Listen");
	if(errno!=0)
		exit(errno);

	while(1)
	{
		int i,j,k,array[20];
		char temp[256];
		i=0;j=0;k=0;
		strcpy(temp," ");
		client_sock_fd=accept(server_sock_fd,(struct sockaddr *)NULL,(socklen_t *)NULL);
		perror("Accept");
		read(client_sock_fd,readbuffer,sizeof(readbuffer));
		perror("Get Data");
		if(strcmp(readbuffer,"stop")==0)
			break;
		strcpy(writebuffer," ");
		for(i=0;i<=strlen(readbuffer);i++)
		{
			if(readbuffer[i]!=':'&&i!=strlen(readbuffer))
			{
				if((readbuffer[i]-'0'<=9))
				temp[j++]=readbuffer[i];
			}
			else
			{

					array[k++]=atoi(temp);
					j=0;
					strcpy(temp," ");

			}
		}
		int ntemp;
		for(i=0;i<k;i++)
		{
			for(j=0;j<k-i-1;j++)
			{
				if(array[j]>array[j+1])
				{
					ntemp=array[j];
					array[j]=array[j+1];
					array[j+1]=ntemp;
				}
			}
		}

		for(i=0;i<k;i++)
		{
			strcpy(temp," ");
			sprintf(temp,"%d ",array[i]);
			strcat(writebuffer,temp);

		}


		write(client_sock_fd,writebuffer,sizeof(writebuffer));
		perror("Send Data");
		close(client_sock_fd);
		perror("Close connection");
		strcpy(readbuffer," ");
	}


	close(server_sock_fd);
    perror("Server Termination");



	return errno;
}

/*
 ============================================================================
 Name        : TCPClient.c
 Author      : www.facebook.com/unix4u
 Version     :
 Copyright   : LGPL
 Description : TCP CLIENT in C, Ansi-style
 ============================================================================
 */

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <arpa/inet.h>
#include <sys/socket.h>
#include <unistd.h>
#include <netinet/in.h>
#include <string.h>
#include <signal.h>

void signalhandler(int signum)
{
	if(SIGALRM==signum)
	{
		printf("Host timed Out\n");
		exit(ETIMEDOUT);
	}
	if(SIGTERM==signum)
	{
		printf("See you later bye\n");
		exit(SIGTERM);
	}


}

int main(int argc,char *argv[]) {

	signal(SIGALRM,signalhandler);
	signal(SIGTERM,signalhandler);

	int socket_fd;
    char writebuffer[256]="",readbuffer[256]="";
    struct sockaddr_in server_addr;
    int i;


    if(argc<4)
    {
    	printf("please run as ./TCPClient <ip-address> <port-no> <numbers>/stop \n");
    	exit(1);
    }

    if(argc>3)
    {
    	strcat(writebuffer,argv[3]);
    for(i=4;i<argc;i++)
    {
    	strcat(writebuffer,":");
    	strcat(writebuffer,argv[i]);

    }
    }

    socket_fd=socket(AF_INET,SOCK_STREAM,0);
    perror("Create socket");
    if(errno)
    	exit(errno);

    server_addr.sin_family=AF_INET;
    server_addr.sin_port=htons(atoi(argv[2]));
    inet_pton(AF_INET,argv[1],&server_addr.sin_addr.s_addr);
    perror("Ip address convertion");
    if(errno)
        exit(errno);

    alarm(5);
    connect(socket_fd,(struct sockaddr *)&server_addr,sizeof(server_addr));
    perror("Connection");
    if(errno)
        exit(errno);

    write(socket_fd,writebuffer,sizeof(writebuffer));
    perror("Send Data");
    if(errno)
        exit(errno);

    read(socket_fd,&readbuffer,sizeof(readbuffer));
    perror("Get Data");
    if(errno)
        exit(errno);

    puts(readbuffer);

    close(socket_fd);
    perror("Connection close");

    return errno;
}

/*
 ============================================================================
 Name        : UDPServer.c
 Author      : www.facebook.com/unix4u
 Version     :
 Copyright   : LGPL
 Description : UDP SERVER in C, Ansi-style
 ============================================================================
 */

#include <stdio.h>
#include <stdlib.h>
#include <netinet/in.h>
#include <errno.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <string.h>
#include <signal.h>

void signalhandler(int signum)
{
	if(SIGTERM==signum)
	{
		printf("See you later bye\n");
		exit(SIGTERM);
	}
}


int main(int argc,char *argv[])
{
	signal(SIGTERM,signalhandler);

	struct sockaddr_in server_addr,client_addr;
	char readbuffer[256]="",writebuffer[256]="";
	int server_sock_fd;
	socklen_t len=sizeof(client_addr);

	if(argc!=2)
	{
		printf("please run as ./UDPServer <port-no>\n");
		exit(1);
	}

	server_sock_fd=socket(AF_INET,SOCK_DGRAM,0);
	perror("Create socket");
	if(errno)
		exit(errno);

	server_addr.sin_family=AF_INET;
	server_addr.sin_port=htons(atoi(argv[1]));
	server_addr.sin_addr.s_addr=htonl(INADDR_ANY);

	bind(server_sock_fd,(struct sockaddr *)&server_addr,sizeof(server_addr));
	perror("Bind");
	if(errno)
		exit(errno);

	while(1)
	{
		int i,j,k,array[20];
		char temp[256];
		i=0;j=0;k=0;

		recvfrom(server_sock_fd,readbuffer,sizeof(readbuffer),0,(struct sockaddr*)&client_addr,&len);
		perror("Get Data");
		if(strcmp(readbuffer,"stop")==0)
			break;
		strcpy(writebuffer," ");
		for(i=0;i<=strlen(readbuffer);i++)
		{
			if(readbuffer[i]!=':'&&i!=strlen(readbuffer))
			{
				if((readbuffer[i]-'0'<=9))
				temp[j++]=readbuffer[i];
			}
			else
			{
				array[k++]=atoi(temp);
				j=0;
				strcpy(temp," ");
			}
		}
		int ntemp;
		for(i=0;i<k;i++)
		{
			for(j=0;j<k-i-1;j++)
			{
				if(array[j]>array[j+1])
				{
					ntemp=array[j];
					array[j]=array[j+1];
					array[j+1]=ntemp;
				}
			}
		}

		for(i=0;i<k;i++)
		{
			strcpy(temp," ");
			sprintf(temp,"%d ",array[i]);
			strcat(writebuffer,temp);
		}
		sendto(server_sock_fd,writebuffer,sizeof(writebuffer),0,(struct sockaddr*)&client_addr,len);
		perror("Send Data");
	}

	close(server_sock_fd);
	perror("Server Termination");

	return errno;
}

/*
 ============================================================================
 Name        : UDPClient.c
 Author      : www.facebook.com/unix4u
 Version     :
 Copyright   : LGPL
 Description : UDP Client in C, Ansi-style
 ============================================================================
 */

#include <stdio.h>
#include <stdlib.h>
#include <netinet/in.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <errno.h>
#include <unistd.h>
#include <string.h>
#include <arpa/inet.h>
#include <signal.h>

void signalhandler(int signum)
{
	printf("Host Timed out\n");
	exit(ETIMEDOUT);
}
int main(int argc,char *argv[]) {

	signal(SIGALRM,signalhandler);

	struct sockaddr_in server_addr;
	socklen_t len=sizeof(server_addr);
	char readbuffer[256]="",writebuffer[256]="";
	int server_sock_fd,i;

	 if(argc<4)
	    {
	    	printf("please run as ./TCPClient <ip-address> <port-no> <numbers>/stop\n");
	    	exit(1);
	    }

	    if(argc>3)
	    {
	    	strcat(writebuffer,argv[3]);
	    	for(i=4;i<argc;i++)
	    	{
	    		strcat(writebuffer,":");
	    		strcat(writebuffer,argv[i]);
	    	}
	    }

	server_sock_fd=socket(AF_INET,SOCK_DGRAM,0);
	perror("Create socket");
	if(errno)
		exit(errno);

	server_addr.sin_family=AF_INET;
	server_addr.sin_port=htons(atoi(argv[2]));
	inet_pton(AF_INET,argv[1],&server_addr.sin_addr.s_addr);
	perror("Ip address convertion");
	if(errno)
		exit(errno);


	sendto(server_sock_fd,writebuffer,sizeof(writebuffer),0,(struct sockaddr *)&server_addr,len);
	perror("Send Data");
	alarm(5);
	recvfrom(server_sock_fd,readbuffer,sizeof(readbuffer),0,(struct sockaddr *)&server_addr,&len);
	perror("Get Data");

	puts(readbuffer);

	close(server_sock_fd);
	perror("Close connection");

	return errno;
}