Re: Changing __FD_SETSIZE to extend select() limit

[Guy Harrison]

Shigeru Mabuchi wrote:

> 
> Hello.
> 
> I'm developing a socket server program on RH Linux 9.
> I use the select() function call to manage the socket I/O.
> However, the maximum file descripters can be handled in
> select() depends on the variable __FD_SETSIZE defined in
> the system header file. ( /usr/include/sys/posix_types.h
> in my case).
> 
> Is it appropiate to simply change the value of this __FD_SETSIZE
> (say, to 4096 instead of the default 1024) in the system header
> file and recompile my program to accomodate more file descripters
> for the select() function call in my server program?

No.

> Would it be harmful to other programs, or the linux system?
> All packages on my server are installed and managed in RPMs.
> 
> Any advice would be greatly appreciated. Thanks!

$ man select
$ man poll

Google on "increase FD_SETSIZE". Many of the groups will be ontopic (it
isn't here as you've no doubt guessed already).