/****************************************************************************
*                                                                           *
*                kep_reload.c: Simple socket-based utility to               *
*                  force a reload of PREDICT's TLE database                 *
*                                                                           *
*       Syntax: kep_reload name_of_server  (default is "localhost")         *
*       Written by: John A. Magliacane, KD2BD on Friday 06-Apr-2001         *
*              Original socket code by Ivan Galysh, KD4HBO                  *
*                      Last modified on:  02-Jun-2001                       *
*                                                                           *
*****************************************************************************
*                                                                           *
* 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 2 of the License or any later    *
* version.                                                                  *
*                                                                           *
* This program is distributed in the hope that it will 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.                                                         *
*                                                                           *
*****************************************************************************/

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

char string[625];

int connectsock(char *host, char *service, char *protocol)
{
	/* This function is used to connect to the server.  "host" is the
	   name of the computer on which PREDICT is running in server mode.
	   "service" is the name of the socket port.  "protocol" is the
	   socket protocol.  It should be set to UDP. */

	struct hostent *phe;
	struct servent *pse;
	struct protoent *ppe;
	struct sockaddr_in sin;
	
	int s, type;
	
	bzero((char *)&sin,sizeof(struct sockaddr_in));
	sin.sin_family=AF_INET;
	
	if ((pse=getservbyname(service,protocol)))
		sin.sin_port=pse->s_port;

	else if ((sin.sin_port=htons((unsigned short)atoi(service)))==0)
	{
		printf("Can't get services\n");
		return -1;
	}

	if ((phe=gethostbyname(host)))
		bcopy(phe->h_addr,(char *)&sin.sin_addr,phe->h_length);

	else if ((sin.sin_addr.s_addr=inet_addr(host))==INADDR_NONE)
	{
		printf("Can't get host: %c%s%c.\n",34,host,34);
		return -1;
	}
	
	if ((ppe=getprotobyname(protocol))==0)
		return -1;

	if (strcmp(protocol,"udp")==0)
		type=SOCK_DGRAM;
	else
		type=SOCK_STREAM;
	
	s=socket(PF_INET,type,ppe->p_proto);

	if (s<0)
	{
		printf("Can't get socket.\n");
		return -1;
	}

	if (connect(s,(struct sockaddr *)&sin,sizeof(sin))<0)
	{
		printf("Can't connect to socket.\n");
		return -1;
	}

	return s;
}

void get_response(int sock, char *buf)
{
	/* This function gets a response from the
	   server in the form of a character string. */

	int n;
	alarm(10); 
	n=read(sock,buf,625);

	if (errno==EINTR)
		return;

	if (n<0)
	{
		alarm(0); 
		return;
	}
	
	buf[n]='\0';
	alarm(0); 
}

char *send_command(host, command)
char *host, *command;
{
	int sk;

	/* This function sends "command" to PREDICT running on
	   machine "host", and returns the result of the command
	   as a pointer to a character string. */

	/* Open a network socket */
	sk=connectsock(host,"predict","udp");

	if (sk<0)
		exit(-1);

	/* Build a command buffer */
	sprintf(string,"%s\n",command);

	/* Send the command to the server */
   	write(sk,command,strlen(string));

	/* clear string[] so it can be re-used for the response */
	string[0]=0;

	/* Get the response */
   	get_response(sk,string);

	/* Close the connection */
   	close(sk);

	return string;
}

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

	if (argc==1)
		send_command("localhost", "RELOAD_TLE");
	else
		for (x=1; x<argc; x++)
			send_command(argv[x],"RELOAD_TLE");

	exit(0);
}

