> -----Original Message-----
> From: rajesh k [mailto:community-noreply@qnx.com]
> Sent: February-20-09 5:41 PM
> To: technology-networking
> Subject: select() call is not working
> 
> HI,
>  any one can help on this.
> select() call is not working on file descriptors. it is not all
> blocking.
> 
> #include<sys/select.h>
> #include <sys/syspage.h>
> #include <fcntl.h>
> #include"nipcinternonblk.h"
> 
> 
> int main(int argc, char *argv[]) {
> 
> 	int sel_res, fd;
> 	fd_set rd_set;
> 
> 	fd = open("/tmp/tst",O_RDWR );
> 
> 
> while(1)
> {
> 	printf("entered whl loop\n");
> 	FD_ZERO(&rd_set);
>                 FD_SET(fd,&rd_set);
> 	sel_res = select(FD_SETSIZE, &rd_set,NULL,NULL,NULL);
> 	printf("select val:%d\n",sel_res);-----------> always giving 1
> 	if(FD_ISSET(chid, &rd_set ))
>                           do something..............
> 
> }
> }
> 
I believe FD_SETSIZE should be equal to fd + 1.  That being said under QNX6 it don't think it makes any sense to do a 
select on a file description that is pointing to a file.

> _______________________________________________
> Technology
> http://community.qnx.com/sf/go/post22673
> 

On Fri, Feb 20, 2009 at 05:40:39PM -0500, rajesh k wrote:
> HI,
>  any one can help on this.
> select() call is not working on file descriptors. it is not all blocking.
> 
> #include<sys/select.h>
> #include <sys/syspage.h>
> #include <fcntl.h>
> #include"nipcinternonblk.h"
> 
> 
> int main(int argc, char *argv[]) {
> 	
> 	int sel_res, fd;
> 	fd_set rd_set;
> 
> 	fd = open("/tmp/tst",O_RDWR );
> 	
> 	
> while(1)
> {
> 	printf("entered whl loop\n");
> 	FD_ZERO(&rd_set);
>                 FD_SET(fd,&rd_set);
> 	sel_res = select(FD_SETSIZE, &rd_set,NULL,NULL,NULL);
> 	printf("select val:%d\n",sel_res);-----------> always giving 1
> 	if(FD_ISSET(chid, &rd_set ))
>                           do something..............
> 
> }
> }

Returning from select() for read means you won't block on read which
I suspect you won't in this example.

Regards,

-seanb