The Linux file descriptor is set to a non-blocking method

PassFcntlset file Descriptor PropertiesFcntl is the use of F_SETFL,F_GETFL, set the file flags, blocking is set to non-blocking, non-blocking is set to block (this can be encapsulated as a basic function in server development)1. Get the file's flags, which is the second parameter of the Open function:

    Flags = FCNTL (fd,f_getfl,0);

2, set the file flags:

     Fcntl (Fd,f_setfl,flags);

3, add a file of flags, such as the file is blocked, want to set to non-blocking:

      Flags = FCNTL (fd,f_getfl,0);      Flags |= O_nonblock;      Fcntl (Fd,f_setfl,flags);

Or one step the way:

     Fcntl (Socket,f_setfl,fcntl (SOCKET,F_GETFL) | O_nonblock);

4, cancel a file flags, such as the file is non-blocking, want to set up to become blocked: 

    Flags = FCNTL (fd,f_getfl,0);    Flags &= ~o_nonblock;    Fcntl (Fd,f_setfl,flags);

PassSocket APIcreate a non-blockingSocket

</pre><pre name= "code" class= "CPP" > #include <sys/types.h> #include <sys/socket.h>int socket ( int domain,int type,int protocal);

Typeparameter specifies the type of service, the type of service is mainlySock_streamServices,Sock_dgreamservice, it is worth noting that theLinuxKernel version2.6.17up,typeThe parameters can accept the above service and accept the following two symbols as well:Sock_nonblock,sock_cloexec,each of them represents the newly createdsockset to non-blocking, and inForkcall when creating a child process is closed in a child processsocket.However, previous versions are not supported.

1. Create blockingSocket

    int fd_sock = socket (af_inet,sock_stream,0);

2. create a non-blocking socket

    int fd_sock = socket (af_inet,sock_stream| sock_nonblock,0);

The above code indicates that a new socket created is non-blocking

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The Linux file descriptor is set to a non-blocking method