Comment déboguer TCP recv()

Question

J'ai une simulation client - server - server socket avec communication bidirectionnelle.

Ma ligne

recv(fd3, serv3_buf, BUFSIZE - 1, 0); 

retours -1

Comment pouvez-vous déboguer recv en utilisant errno.h?

Answer 1

Voici l'explication de l'utilisateur (ual) des relevés d'erreur à recv!

ERREURS Voici quelques erreurs standard générées par la couche socket. Des erreurs supplémentaires peuvent être générées et renvoyées à partir des prototypes sous-jacents ; voir leurs pages de manuel.

EAGAIN or EWOULDBLOCK 
      The socket is marked nonblocking and the receive operation would 
      block, or a receive timeout had been set and the timeout expired 
      before data was received. POSIX.1-2001 allows either error to 
      be returned for this case, and does not require these constants 
      to have the same value, so a portable application should check 
      for both possibilities. 

    EBADF The argument sockfd is an invalid descriptor. 

    ECONNREFUSED 
      A remote host refused to allow the network connection (typically 
      because it is not running the requested service). 

    EFAULT The receive buffer pointer(s) point outside the process's 
      address space. 

    EINTR The receive was interrupted by delivery of a signal before any 
      data were available; see signal(7). 

    EINVAL Invalid argument passed. 

    ENOMEM Could not allocate memory for recvmsg(). 

    ENOTCONN 
      The socket is associated with a connection-oriented protocol and 
      has not been connected (see connect(2) and accept(2)). 

    ENOTSOCK 
      The argument sockfd does not refer to a socket. 

Vous pouvez utiliser pour gérer une chaîne d'erreur perror() et strerror() lors du retour de recv -1.

Voir l'homme concerné (uel) pour l'explication:

perror

strerror