explain_connect(3)					     Library Functions Manual						explain_connect(3)

NAME

       explain_connect - explain connect(2) errors

SYNOPSIS

       #include <libexplain/connect.h>
       const char *explain_connect(int fildes, const struct sockaddr *serv_addr, int serv_addr_size);
       const char *explain_errno_connect(int errnum, int fildes, const struct sockaddr *serv_addr, int serv_addr_size);
       void explain_message_connect(char *message, int message_size, int fildes, const struct sockaddr *serv_addr, int serv_addr_size);
       void  explain_message_errno_connect(char  *message,  int  message_size,	int  errnum,  int  fildes,  const  struct sockaddr *serv_addr, int
       serv_addr_size);

DESCRIPTION

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

   explain_connect
       const char *explain_connect(int fildes, const struct sockaddr *serv_addr, int serv_addr_size);

       The explain_connect function is used to obtain an explanation of an error returned by the connect(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 following example:
	      if (connect(fildes, serv_addr, serv_addr_size) < 0)
	      {
		  fprintf(stderr, "%s
", explain_connect(fildes, serv_addr,
		      serv_addr_size));
		  exit(EXIT_FAILURE);
	      }

       fildes  The original fildes, exactly as passed to the connect(2) system call.

       serv_addr
	       The original serv_addr, exactly as passed to the connect(2) system call.

       serv_addr_size
	       The original serv_addr_size, exactly as passed to the connect(2) system 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,  including  other
	       threads.

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

   explain_errno_connect
       const char *explain_errno_connect(int errnum, int fildes, const struct sockaddr *serv_addr, int serv_addr_size);

       The explain_errno_connect function is used to obtain an explanation of an error returned by the connect(2) system call.	The least the mes-
       sage 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 following example:
	      if (connect(fildes, serv_addr, serv_addr_size) < 0)
	      {
		  int err = errno;
		  fprintf(stderr, "%s
", explain_errno_connect(err,
		      fildes, serv_addr, serv_addr_size));
		  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 neces-
	       sary 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.

       fildes  The original fildes, exactly as passed to the connect(2) system call.

       serv_addr
	       The original serv_addr, exactly as passed to the connect(2) system call.

       serv_addr_size
	       The original serv_addr_size, exactly as passed to the connect(2) system 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, including other
	       threads.

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

   explain_message_connect
       void explain_message_connect(char *message, int message_size, int fildes, const struct sockaddr *serv_addr, int serv_addr_size);

       The explain_message_connect function may be used to  obtain an explanation of an error returned by the connect(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 following example:
	      if (connect(fildes, serv_addr, serv_addr_size) < 0)
	      {
		  char message[3000];
		  explain_message_connect(message, sizeof(message),
		      fildes, serv_addr, serv_addr_size);
		  fprintf(stderr, "%s
", 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 returned message.

       fildes  The original fildes, exactly as passed to the connect(2) system call.

       serv_addr
	       The original serv_addr, exactly as passed to the connect(2) system call.

       serv_addr_size
	       The original serv_addr_size, exactly as passed to the connect(2) system call.

   explain_message_errno_connect
       void  explain_message_errno_connect(char  *message,  int  message_size,	int  errnum,  int  fildes,  const  struct sockaddr *serv_addr, int
       serv_addr_size);

       The explain_message_errno_connect function may be used to obtain an explanation of an error returned by the connect(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 following example:
	      if (connect(fildes, serv_addr, serv_addr_size) < 0)
	      {
		  int err = errno;
		  char message[3000];
		  explain_message_errno_connect(message, sizeof(message), err,
		      fildes, serv_addr, serv_addr_size);
		  fprintf(stderr, "%s
", 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 returned message.

       errnum  The error value to be decoded, usually obtained from the errno global variable just before this function is called.  This is neces-
	       sary 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.

       fildes  The original fildes, exactly as passed to the connect(2) system call.

       serv_addr
	       The original serv_addr, exactly as passed to the connect(2) system call.

       serv_addr_size
	       The original serv_addr_size, exactly as passed to the connect(2) system call.

SEE ALSO

       connect(2)
	       initiate a connection on a socket

       explain_connect_or_die(3)
	       initiate a connection on a socket and report errors

COPYRIGHT

       libexplain version 0.52
       Copyright (C) 2008 Peter Miller

																explain_connect(3)