Hi,

my project is VOIP. I'm beginer in programming.I use Fedora Core 4.I wrote socket program to send data other computer and this is code:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <errno.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include<unistd.h>
#include<netinet/in.h>
#include<sys/wait.h>
#include<signal.h>
#define DATA_PORT 5014
int main(){
int j;
int sockfd;
struct sockaddr_in Target,Source;
Source.sin_family=AF_INET;
Source.sin_addr.s_addr=inet_addr("192.168.0.2");
Source.sin_port=htons(0);
if((sockfd=socket(AF_INET,SOCK_DGRAM,0))==-1)
{
printf ("\n Socket for data msgs cannot be created\n");
exit(-1);}
if(bind(sockfd,(struct sockaddr*)&Source,sizeof(Source))==-1)
{ perror("\n Data socket cannot be binded to OS\n");
exit(-1);}
Target.sin_family=AF_INET;
Target.sin_port=htons(DATA_PORT);
Target.sin_addr.s_addr=inet_addr("192.168.0.4");
while(1){printf("sent ok\n");
j=sendto(sockfd,"alah akbar",10,0,(struct sockaddr*)&Target, sizeof(Target));
}
return 0;
}


and no error in this code


then I wrote socket program to receive the data from the first computer and this is code:


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

#define DATA_PORT 5000
int buf[10];
int g;

int main()
{
int j;
int sockfd;
struct sockaddr_in Target;
Target.sin_family=AF_INET;
Target.sin_port=htons(DATA_PORT);
Target.sin_addr.s_addr=inet_addr("192.168.0.3");
if((sockfd=socket(AF_INET,SOCK_DGRAM,0))==-1)
{
printf("\n Socket for data msgs cannot be created\n");
exit(-1);
}

if(bind(sockfd,(struct sockaddr*)&Target,sizeof(Target))==-1)
{
perror("\n Data socket cannot be binded to OS\n");
Exit(-1);
}

g=sizeof(Target);

while(1)
{
j=recvfrom(sockfd,buf,10,0,(struct sockaddr*
&Target,&g);
printf("%s\n"buf);
}

return 0;
}

but this code has error in line 43 this error is: (syntax error before struct )

I tried too much to repair this error but I cannot. I beginer in programming,please can you help me, thank you

Please post all code in code tags ([ code ] this is code [ / code ] -- without the spaces) if you want people to read it (and please don't post anything you don't want people to read). Also, your question is related to programming, so it really belongs in the Programming (sub)forum.

grovel through the headers in decreasing order of relevance to see if they define the relevant struct (sockaddr_in, right?). 'grep -C 4 sockaddr_in <filename>' might come in handy.

Moved: This thread is more suitable in Programming and has been moved accordingly to help your thread/question get the exposure it deserves.

It'd be helpful to have the program in code tags, because it's now hard to find out which line is 43. It looks to me that's
There's a simple mistake, no ). It should be

Hi,
I'm sorry for asking again.
my project is VOIP. I'm beginer in programming.I wrote socket program to send data other computer and this is code:
[

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <errno.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include<unistd.h>
#include<netinet/in.h>
#include<sys/wait.h>
#include<signal.h>
#define DATA_PORT 5014
int main(){
int j;
int sockfd;
struct sockaddr_in Target,Source;
Source.sin_family=AF_INET;
Source.sin_addr.s_addr=inet_addr("192.168.0.2");
Source.sin_port=htons(0);
if((sockfd=socket(AF_INET,SOCK_DGRAM,0))==-1)
{
printf ("\n Socket for data msgs cannot be created\n");
exit(-1);}
if(bind(sockfd,(struct sockaddr*)&Source,sizeof(Source))==-1)
{ perror("\n Data socket cannot be binded to OS\n");
exit(-1);}
Target.sin_family=AF_INET;
Target.sin_port=htons(DATA_PORT);
Target.sin_addr.s_addr=inet_addr("192.168.0.4");
while(1){printf("sent ok\n");
j=sendto(sockfd,"alah akbar",10,0,(struct sockaddr*)&Target, sizeof(Target));
}
return 0;
}

]


and no error in this code


then I wrote socket program to receive the data from the first computer I adjust in this code as you tell me,and this is code:

[

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

#define DATA_PORT 5000
int buf[10];
int g;

int main()
{
int j;
int sockfd;
struct sockaddr_in Target;
Target.sin_family=AF_INET;
Target.sin_port=htons(DATA_PORT);
Target.sin_addr.s_addr=inet_addr("192.168.0.3");
if((sockfd=socket(AF_INET,SOCK_DGRAM,0))==-1)
{
printf("\n Socket for data msgs cannot be created\n");
exit(-1);
}

if(bind(sockfd,(struct sockaddr*)&Target,sizeof(Target))==-1)
{
perror("\n Data socket cannot be binded to OS\n");
Exit(-1);
}

g=sizeof(Target);

while(1)
{
j=recvfrom(sockfd,buf,10,0,(struct sockaddr*)&Target,&g);

printf("%s\n",buf);
}

return 0;
}

]

but this code has error in line 42 this error is: (warning: pointer targets in passing argument 6 of 'recvfrom' differ in signedness )

I tried too much to repair this error but I cannot. I beginer in programming,please can you help me, thank you

Change "int g" to ... or ...

Change "j=recvfrom(sockfd,buf,10,0,(struct sockaddr*)&Target,&g);" to
Just FYI: <= On your platform, "socklen_t" happens to be unsigned, and the C/C++
standard dictates that an int pointer should be flagged as "incompatible" with
an unsigned int pointer, hence the need to cast (unsigned int *)

Tanks for you very very much for helping me to correct the error in my codes,but when I running this programs (sender&receiver),message appear at the bottom of debugger window:

((no debugging symbols found)using host libthread_db library "/lib/libthread_db.so.1")

I cannot understand this message.Are this message affect on running of my programs?.Please can you help me,thank you.

The debugger can't find symbol list for the library. It's understandable (they take space) and should not cause any harm (only if something fails in that library - debugging may be harder).