sir,
i am traping some of the system calls for my application by preoading concept.
Rightnow i am traping READ ,WRITE ,CLOSE ,OPEN .
What i found after my execution is somewhat interesting. It calls READ,WRITE,CLOSE system calls without any call to OPEN.
How is the file descriptor used in READ,WRITE,CLOSE created without calling to OPEN ?
I suspect it might be using socket() system call instead of OPEN.

With thanks in advance,
barun

Absent specific examples it's hard to say, but I daresay that the OPEN call is out there somewhere. Check the underlying source-code...

Here goes my code. Here i am preloading the open() system call and printing that Open() is called with the process-id.

int open(const char* path, int flags) {
char * error;
char str[81];
void * handle;
int ret=0;
pid_t pid;

int (*original) (const char *,int);

handle=dlopen("/lib/libc-2.3.3.so",RTLD_LAZY);
if(handle==NULL) {
error=dlerror();
printf("\n error in dlopen : %s",error);
exit(0);
}

original=dlsym(handle,"open");
if( (error=dlerror()) !=NULL) {
printf("error in dlsym : %s",error);
exit(0);
}

ret=original(path,flags);
if(strcmp(path,"/dev/usb/lp0")==0) {
printf("\nOPEN : %s\n", path);
printf("Fd is %d\n", ret);
}
return(ret);
}


Now figure out the problem .