Thak you for your help. this helped to solve the problem. Now I am using pcap_loop to capture packets. The project 
compiles and builds but during debugging when I run pcap_loop function the program stops and shows 

No source available for "pcap_loop() " 


my code


#include <stdlib.h>
#include <stdio.h>
#include "pcap.h"

/* prototype of the packet handler */
void packet_handler(u_char *param, const struct pcap_pkthdr *header, const u_char *pkt_data);

int main(int argc, char *argv[]) {
	pcap_if_t *alldevs;
	pcap_if_t *d;
	int inum;
	int i=0;
	pcap_t *adhandle;
	char errbuf[PCAP_ERRBUF_SIZE];

	    /* Retrieve the device list on the local machine */
	    if (pcap_findalldevs(&alldevs, errbuf) == -1)
	    {
	        fprintf(stderr,"Error in pcap_findalldevs: %s\n", errbuf);
	        exit(1);
	    }

	    /* Print the list */
	    for(d=alldevs; d; d=d->next)
	    {
	        printf("%d. %s", ++i, d->name);
	        if (d->description)
	            printf(" (%s)\n", d->description);
	        else
	            printf(" (No description available)\n");
	    }

	    if(i==0)
	    {
	        printf("\nNo interfaces found! Make sure WinPcap is installed.\n");
	        return -1;
	    }

	    printf("Enter the interface number (1-%d):",i);
	    //scanf("%d", &inum);
	    inum=1;

	    if(inum < 1 || inum > i)
	    {
	        printf("\nInterface number out of range.\n");
	        /* Free the device list */
	        pcap_freealldevs(alldevs);
	        return -1;
	    }

	    /* Jump to the selected adapter */
	    for(d=alldevs, i=0; i< inum-1 ;d=d->next, i++);

	    /* Open the device */

	    adhandle=pcap_open_live(d->name, 65536, 1, 20, errbuf);

	    if (adhandle=NULL)
	    {
	        fprintf(stderr,"\nUnable to open the adapter. %s is not supported by WinPcap\n", d->name);
	        /* Free the device list */
	        pcap_freealldevs(alldevs);
	        return -1;
	    }

	    //printf("\nlistening on %s...\n", d->description);

	    /* At this point, we don't need any more the device list. Free it */
	    pcap_freealldevs(alldevs);

	    /* start the capture */
	    pcap_loop(adhandle, 0, packet_handler, NULL);

	return EXIT_SUCCESS;
}

/* Callback function invoked by libpcap for every incoming packet */
void packet_handler(u_char *param, const struct pcap_pkthdr *header, const u_char *pkt_data)
{
    struct tm *ltime;
    char timestr[16];
    time_t local_tv_sec;

    /* convert the timestamp to readable format */
    local_tv_sec = header->ts.tv_sec;
    ltime=localtime(&local_tv_sec);
    strftime( timestr, sizeof timestr, "%H:%M:%S", ltime);

    printf("%s,%.6d len:%d\n", timestr, header->ts.tv_usec, header->len);

}

> > 
> > You mean I have to add libpcap in Project\linker\Extra library\pcap
> 
> I guess so.  However the ide lets you do it :)
> 
> > 
> > I did that it gives me more error.
> > 
> > 
> > Description	Resource	Path	Location	Type
> >  undefined reference to `ether_hostton'	packetcapture2		line 0	C/C++ Problem
> 
> >  undefined reference to `freeaddrinfo'	packetcapture2		line 0	C/C++ Problem
> >  undefined reference to `freeifaddrs'	packetcapture2		line 0	C/C++ Problem
> >  undefined reference to `getaddrinfo'	packetcapture2		line 0	C/C++ Problem
> >  undefined reference to `gethostbyname'	packetcapture2		line 0	C/C++ Problem
> 
> >  undefined reference to `getifaddrs'	packetcapture2		line 0	C/C++ Problem
> >  undefined reference to `getnetbyname'	packetcapture2		line 0	C/C++ Problem
> >  undefined reference to `getprotobyname'	packetcapture2		line 0	C/C++ 
> Problem
> >  undefined reference to `getservbyname'	packetcapture2		line 0	C/C++ Problem
> 
> >  undefined reference to `ioctl_socket'	packetcapture2		line 0	C/C++ Problem
> >  undefined reference to `socket'	packetcapture2		line 0	C/C++ Problem
> > C:/QNX641/target/qnx6/x86/usr/lib\libpcap.a(pcap-bpf.o): more undefined 
> references to `ioctl_socket' follow	packetcapture2		line 0	C/C++ Problem
> > make[2]: *** [C:/ide-4.6-workspace/packetcapture2/x86/o-g/packetcapture2_g] 
> Error 1	packetcapture2		line 0	C/C++ Problem
> > make[2]: *** [C:/ide-4.6-workspace/packetcapture2/x86/o/packetcapture2] 
> Error 1	packetcapture2		line 0	C/C++ Problem
> > 
> 
> These are in libsocket.
> 
> -seanb

Re: using pcap.h

Thak you for your help. this helped to solve the problem. Now I am using pcap_loop to capture packets. The project 
compiles and builds but during debugging when I run pcap_loop function the program stops and shows 

No source available for "pcap_loop() " 


my code


#include <stdlib.h>
#include <stdio.h>
#include "pcap.h"

/* prototype of the packet handler */
void packet_handler(u_char *param, const struct pcap_pkthdr *header, const u_char *pkt_data);

int main(int argc, char *argv[]) {
	pcap_if_t *alldevs;
	pcap_if_t *d;
	int inum;
	int i=0;
	pcap_t *adhandle;
	char errbuf[PCAP_ERRBUF_SIZE];

	    /* Retrieve the device list on the local machine */
	    if (pcap_findalldevs(&alldevs, errbuf) == -1)
	    {
	        fprintf(stderr,"Error in pcap_findalldevs: %s\n", errbuf);
	        exit(1);
	    }

	    /* Print the list */
	    for(d=alldevs; d; d=d->next)
	    {
	        printf("%d. %s", ++i, d->name);
	        if (d->description)
	            printf(" (%s)\n", d->description);
	        else
	            printf(" (No description available)\n");
	    }

	    if(i==0)
	    {
	        printf("\nNo interfaces found! Make sure WinPcap is installed.\n");
	        return -1;
	    }

	    printf("Enter the interface number (1-%d):",i);
	    //scanf("%d", &inum);
	    inum=1;

	    if(inum < 1 || inum > i)
	    {
	        printf("\nInterface number out of range.\n");
	        /* Free the device list */
	        pcap_freealldevs(alldevs);
	        return -1;
	    }

	    /* Jump to the selected adapter */
	    for(d=alldevs, i=0; i< inum-1 ;d=d->next, i++);

	    /* Open the device */

	    adhandle=pcap_open_live(d->name, 65536, 1, 20, errbuf);

	    if (adhandle=NULL)
	    {
	        fprintf(stderr,"\nUnable to open the adapter. %s is not supported by WinPcap\n", d->name);
	        /* Free the device list */
	        pcap_freealldevs(alldevs);
	        return -1;
	    }

	    //printf("\nlistening on %s...\n", d->description);

	    /* At this point, we don't need any more the device list. Free it */
	    pcap_freealldevs(alldevs);

	    /*...