Hi Randi, Basically the select syscall check the kernel buffer or in other words it just waiting to be notified by the kernel that there are pending data to read/write, it doesn't store any file-descriptor's related data. - Ardhan --- nightdecoder@xxxxxxxxx wrote: From: Randi Botse <nightdecoder@xxxxxxxxx> To: linux-c-programming@xxxxxxxxxxxxxxx Subject: select() timeout question Date: Wed, 25 Nov 2009 03:29:33 -0500 Hi All, Im now learning the Linux's select() system call, #include <sys/select.h> int select(int fd, fd_set *rset, fd_set *wset, fd_set *excepfs, struct timeval *timeout); I want to receive notification when the given file descriptor is ready to read, i use TCP socket connection to demonstrate this, one for the sender and other for the receiver, with normal condition, when the sender send data via write(), the select() returns and tell the receiver there are data to read. My question is: what happen when the receiver's select() is reaching it's timeout while the sender send data? should the notification and it's data lost (discarded)? Based on my above experiment, select() never fail to notify although it's in timeout state, and i awalys can read the data, i'm curious with this, but i'm not sure if this always right. Thanks before. Randi, -- To unsubscribe from this list: send the line "unsubscribe linux-c-programming" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html _____________________________________________________________ Listen to KNAC, Hit the Home page and Tune In Live! ---> http://www.knac.com -- To unsubscribe from this list: send the line "unsubscribe linux-c-programming" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html