( NevemTeve | 2025. 09. 11., cs – 11:19 )

Szabványtalan Linux-on a könnyen megtalálható /usr/include/asm-generic/errno.h file-ban:

#define EWOULDBLOCK EAGAIN /* Operation would block */

Valamint a /usr/include/asm-generic/errno-base.h file-ban:

#define EAGAIN 11  /* Try again */

Linuxon a read(2) manual a következőt írja:

EAGAIN or EWOULDBLOCK
  The file descriptor fd refers to a socket and has been marked
  nonblocking (O_NONBLOCK), and the read would block.
  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.