packet capturing tex file

hi every one i have taken a code of packet capturing from net and i am saving that information in a text file
but the problem is that even i have close the file using close() function but it is still created and i think there are not
packets in the network but is is still created i delete it and it is again created. any idea please tell me
here is the part where i have implemented filing. (i have run this code on terminal )

void packetHandler(u_char *userData, const struct pcap_pkthdr* pkthdr, const u_char* packet)
 {

FILE *f1;

   const struct ether_header* ethernetHeader;
 const struct ip* ipHeader;
 const struct udphdr* udpHeader;
        const struct tcphdr*tcpHeader;
 char sourceIp[INET_ADDRSTRLEN];
 char destIp[INET_ADDRSTRLEN];
        char * transport_protocol;
        char sp[5] ,dp[5];
  int sourcePort,destPort;
 u_char *data;
 int dataLength = 0;
        char dataStr[100]="";
        char filedata[500]="";

 ethernetHeader = (struct ether_header*)packet;
 if (ntohs(ethernetHeader->ether_type) == ETHERTYPE_IP)
                {
  ipHeader = (struct ip*)(packet + sizeof(struct ether_header));
  inet_ntop(AF_INET, &(ipHeader->ip_src), sourceIp, INET_ADDRSTRLEN);
  inet_ntop(AF_INET, &(ipHeader->ip_dst), destIp, INET_ADDRSTRLEN);

  if (ipHeader->ip_p == IPPROTO_UDP)
                 {

                   transport_protocol = "UDP";
     udpHeader = (struct udphdr*)(packet + sizeof(struct ether_header) + sizeof(struct ip));
     sourcePort = ntohs(udpHeader->source);
                   sprintf(sp,"%d",ntohs(udpHeader->source));
     destPort = ntohs(udpHeader->dest);
                   data = (u_char*)(packet + sizeof(struct ether_header) + sizeof(struct ip) + sizeof(struct udphdr));
     dataLength = pkthdr->len - (sizeof(struct ether_header) + sizeof(struct ip) + sizeof(struct udphdr));

             }
               else if (ipHeader->ip_p == IPPROTO_TCP)
                 {
                  transport_protocol = "TCP";
                  tcpHeader = (struct tcphdr*)(packet + sizeof(struct ether_header) + sizeof(struct ip));
    sourcePort = ntohs(tcpHeader->source);
    destPort = ntohs(tcpHeader->dest);
    data = (u_char*)(packet + sizeof(struct ether_header) + sizeof(struct ip) + sizeof(struct tcphdr));
    dataLength = pkthdr->len - (sizeof(struct ether_header) + sizeof(struct ip) + sizeof(struct tcphdr));

             }

        }

sprintf(sp,"%d",sourcePort);
sprintf(dp,"%d",destPort);

f1=fopen("info.txt","a");
fputs(sourceIp,f1);
fputs("\n",f1);

fputs(destIp,f1);
fputs(" ",f1);

fputs(sp,f1);
fputs(" ",f1);

fputs(dp,f1);
fputs(" ",f1);

fputs("\n",f1);

fclose(f1);

} //end function

thanks in adcance