Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages

  
 
  

home | help
explain_setsockopt(3)	   Library Functions Manual	 explain_setsockopt(3)

NAME
       explain_setsockopt - explain setsockopt(2) errors

SYNOPSIS
       #include	<libexplain/setsockopt.h>
       const  char  *explain_setsockopt(int  fildes, int level,	int name, void
       *data, socklen_t	data_size);
       const char *explain_errno_setsockopt(int	errnum,	int fildes, int	level,
       int name, void *data, socklen_t data_size);
       void  explain_message_setsockopt(char  *message,	 int message_size, int
       fildes, int level, int name, void *data,	socklen_t data_size);
       void explain_message_errno_setsockopt(char *message, int	 message_size,
       int  errnum,  int  fildes,  int	level, int name, void *data, socklen_t
       data_size);

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

   explain_setsockopt
       const  char  *explain_setsockopt(int  fildes, int level,	int name, void
       *data, socklen_t	data_size);

       The explain_setsockopt function is used to obtain an explanation	of  an
       error returned by the setsockopt(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 (setsockopt(fildes, level, name, data,	data_size) < 0)
	      {
		  fprintf(stderr, "%s\n", explain_setsockopt(fildes,
		      level, name, data, data_size));
		  exit(EXIT_FAILURE);
	      }

       The  above  code	 example is available pre-packaged as the explain_set-
       sockopt_or_die(3) function.

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

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

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

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

       data_size
	       The original data_size, exactly as passed to the	 setsockopt(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,  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_setsockopt
       const char *explain_errno_setsockopt(int	errnum,	int fildes, int	level,
       int name, void *data, socklen_t data_size);

       The  explain_errno_setsockopt function is used to obtain	an explanation
       of an error returned by the setsockopt(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 (setsockopt(fildes, level, name, data,	data_size) < 0)
	      {
		  int err = errno;
		  fprintf(stderr, "%s\n", explain_errno_setsockopt(err,
		      fildes, level, name, data, data_size));
		  exit(EXIT_FAILURE);
	      }

       The  above  code	 example is available pre-packaged as the explain_set-
       sockopt_or_die(3) function.

       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.

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

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

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

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

       data_size
	       The original data_size, exactly as passed to the	 setsockopt(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,  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_setsockopt
       void explain_message_setsockopt(char *message,  int  message_size,  int
       fildes, int level, int name, void *data,	socklen_t data_size);

       The  explain_message_setsockopt	function may be	used to	 obtain	an ex-
       planation of an error returned by the setsockopt(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 (setsockopt(fildes, level, name, data,	data_size) < 0)
	      {
		  char message[3000];
		  explain_message_setsockopt(message, sizeof(message),
		      fildes, level, name, data, data_size);
		  fprintf(stderr, "%s\n", message);
		  exit(EXIT_FAILURE);
	      }

       The  above  code	 example is available pre-packaged as the explain_set-
       sockopt_or_die(3) function.

       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.

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

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

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

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

       data_size
	       The  original data_size,	exactly	as passed to the setsockopt(2)
	       system call.

   explain_message_errno_setsockopt
       void explain_message_errno_setsockopt(char *message, int	 message_size,
       int  errnum,  int  fildes,  int	level, int name, void *data, socklen_t
       data_size);

       The explain_message_errno_setsockopt function may be used to obtain  an
       explanation of an error returned	by the setsockopt(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 (setsockopt(fildes, level, name, data,	data_size) < 0)
	      {
		  int err = errno;
		  char message[3000];
		  explain_message_errno_setsockopt(message, sizeof(message),
		      err, fildes, level, name,	data, data_size);
		  fprintf(stderr, "%s\n", message);
		  exit(EXIT_FAILURE);
	      }

       The  above  code	 example is available pre-packaged as the explain_set-
       sockopt_or_die(3) function.

       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.

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

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

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

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

       data_size
	       The  original data_size,	exactly	as passed to the setsockopt(2)
	       system call.

SEE ALSO
       setsockopt(2)
	       get and set options on sockets

       explain_setsockopt_or_die(3)
	       get and set options on sockets and report errors

COPYRIGHT
       libexplain version 1.3
       Copyright (C) 2009 Peter	Miller

							 explain_setsockopt(3)

NAME | SYNOPSIS | DESCRIPTION | SEE ALSO | COPYRIGHT

Want to link to this manual page? Use this URL:
<https://www.freebsd.org/cgi/man.cgi?query=explain_setsockopt&sektion=3&manpath=FreeBSD+12.2-RELEASE+and+Ports>

home | help