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explain_socket(3)	   Library Functions Manual	     explain_socket(3)

NAME
       explain_socket -	explain	socket(2) errors

SYNOPSIS
       #include	<libexplain/socket.h>
       const char *explain_socket(int domain, int type,	int protocol);
       const  char *explain_errno_socket(int errnum, int domain, int type, int
       protocol);
       void explain_message_socket(char	*message, int  message_size,  int  do-
       main, int type, int protocol);
       void  explain_message_errno_socket(char *message, int message_size, int
       errnum, int domain, int type, int protocol);

DESCRIPTION
       These functions may be used to obtain explanations for errors  returned
       by the socket(2)	system call.

   explain_socket
       const char *explain_socket(int domain, int type,	int protocol);

       The  explain_socket function is used to obtain an explanation of	an er-
       ror returned by the socket(2) system call.  The least the message  will
       contain	is  the	 value of strerror(errno), but usually it will do much
       better, and indicate the	underlying cause in more detail.

       The errno global	variable will be used to obtain	the error value	to  be
       decoded.

       This  function  is intended to be used in a fashion similar to the fol-
       lowing example:
	      if (socket(domain, type, protocol) < 0)
	      {
		  fprintf(stderr, "%s\n", explain_socket(domain, type, protocol));
		  exit(EXIT_FAILURE);
	      }

       domain  The original domain, exactly as passed to the socket(2)	system
	       call.

       type    The  original  type,  exactly as	passed to the socket(2)	system
	       call.

       protocol
	       The original protocol, exactly as passed	to the socket(2)  sys-
	       tem call.

       Returns:
	       The  message  explaining	 the  error.   This  message buffer is
	       shared by all libexplain	functions which	do not supply a	buffer
	       in  their  argument list.  This will be overwritten by the next
	       call to any libexplain function which shares this  buffer,  in-
	       cluding other threads.

       Note: This function is not thread safe, because it shares a return buf-
       fer across all threads, and many	other functions	in this	library.

   explain_errno_socket
       const char *explain_errno_socket(int errnum, int	domain,	int type,  int
       protocol);

       The  explain_errno_socket  function is used to obtain an	explanation of
       an error	returned by the	socket(2) system call.	The least the  message
       will  contain  is the value of strerror(errnum),	but usually it will do
       much better, and	indicate the underlying	cause in more detail.

       This function is	intended to be used in a fashion similar to  the  fol-
       lowing example:
	      if (socket(domain, type, protocol) < 0)
	      {
		  int err = errno;
		  fprintf(stderr, "%s\n", explain_errno_socket(err,
		      domain, type, protocol));
		  exit(EXIT_FAILURE);
	      }

       errnum  The  error value	to be decoded, usually obtained	from the errno
	       global variable just before this	function is called.   This  is
	       necessary  if you need to call any code between the system call
	       to be explained and this	function, because many libc  functions
	       will alter the value of errno.

       domain  The  original domain, exactly as	passed to the socket(2)	system
	       call.

       type    The original type, exactly as passed to	the  socket(2)	system
	       call.

       protocol
	       The  original protocol, exactly as passed to the	socket(2) sys-
	       tem call.

       Returns:
	       The message explaining  the  error.   This  message  buffer  is
	       shared by all libexplain	functions which	do not supply a	buffer
	       in their	argument list.	This will be overwritten by  the  next
	       call  to	 any libexplain	function which shares this buffer, in-
	       cluding other threads.

       Note: This function is not thread safe, because it shares a return buf-
       fer across all threads, and many	other functions	in this	library.

   explain_message_socket
       void  explain_message_socket(char  *message,  int message_size, int do-
       main, int type, int protocol);

       The explain_message_socket function may be used to  obtain an  explana-
       tion  of	an error returned by the socket(2) system call.	 The least the
       message will contain is the value of strerror(errno),  but  usually  it
       will do much better, and	indicate the underlying	cause in more detail.

       The  errno global variable will be used to obtain the error value to be
       decoded.

       This function is	intended to be used in a fashion similar to  the  fol-
       lowing example:
	      if (socket(domain, type, protocol) < 0)
	      {
		  char message[3000];
		  explain_message_socket(message, sizeof(message), domain, type, protocol);
		  fprintf(stderr, "%s\n", message);
		  exit(EXIT_FAILURE);
	      }

       message The  location  in  which	 to  store the returned	message.  If a
	       suitable	message	return buffer is supplied,  this  function  is
	       thread safe.

       message_size
	       The  size  in  bytes  of	the location in	which to store the re-
	       turned message.

       domain  The original domain, exactly as passed to the socket(2)	system
	       call.

       type    The  original  type,  exactly as	passed to the socket(2)	system
	       call.

       protocol
	       The original protocol, exactly as passed	to the socket(2)  sys-
	       tem call.

   explain_message_errno_socket
       void  explain_message_errno_socket(char *message, int message_size, int
       errnum, int domain, int type, int protocol);

       The explain_message_errno_socket	function may be	used to	obtain an  ex-
       planation of an error returned by the socket(2) system call.  The least
       the message will	contain	is the value of	strerror(errnum), but  usually
       it  will	 do much better, and indicate the underlying cause in more de-
       tail.

       This function is	intended to be used in a fashion similar to  the  fol-
       lowing example:
	      if (socket(domain, type, protocol) < 0)
	      {
		  int err = errno;
		  char message[3000];
		  explain_message_errno_socket(message,	sizeof(message), err,
		      domain, type, protocol);
		  fprintf(stderr, "%s\n", message);
		  exit(EXIT_FAILURE);
	      }

       message The  location  in  which	 to  store the returned	message.  If a
	       suitable	message	return buffer is supplied,  this  function  is
	       thread safe.

       message_size
	       The  size  in  bytes  of	the location in	which to store the re-
	       turned message.

       errnum  The error value to be decoded, usually obtained from the	 errno
	       global  variable	 just before this function is called.  This is
	       necessary if you	need to	call any code between the system  call
	       to  be explained	and this function, because many	libc functions
	       will alter the value of errno.

       domain  The original domain, exactly as passed to the socket(2)	system
	       call.

       type    The  original  type,  exactly as	passed to the socket(2)	system
	       call.

       protocol
	       The original protocol, exactly as passed	to the socket(2)  sys-
	       tem call.

SEE ALSO
       socket(2)
	       create an endpoint for communication

       explain_socket_or_die(3)
	       create an endpoint for communication and	report errors

COPYRIGHT
       libexplain version 1.3
       Copyright (C) 2008 Peter	Miller

							     explain_socket(3)

NAME | SYNOPSIS | DESCRIPTION | SEE ALSO | COPYRIGHT

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