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

FreeBSD Manual Pages

  
 
  

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

NAME
       explain_setgroups - explain setgroups(2)	errors

SYNOPSIS
       #include	<libexplain/setgroups.h>
       const char *explain_setgroups(size_t data_size, const gid_t *data);
       const char *explain_errno_setgroups(int errnum, size_t data_size, const
       gid_t *data);
       void explain_message_setgroups(char *message, int message_size, size_t
       data_size, const	gid_t *data);
       void explain_message_errno_setgroups(char *message, int message_size,
       int errnum, size_t data_size, const gid_t *data);

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

   explain_setgroups
       const char *explain_setgroups(size_t data_size, const gid_t *data);

       The  explain_setgroups  function	is used	to obtain an explanation of an
       error returned by the setgroups(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.

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

       data    The original data, exactly as passed to the setgroups(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 buf-
       fer across all threads, and many	other functions	in this	library.

       Example:	This function is intended to be	used in	a fashion  similar  to
       the following example:
	      if (setgroups(data_size, data) < 0)
	      {
		  fprintf(stderr, "%s\n", explain_setgroups(data_size, data));
		  exit(EXIT_FAILURE);
	      }

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

   explain_errno_setgroups
       const char *explain_errno_setgroups(int errnum, size_t data_size, const
       gid_t *data);

       The  explain_errno_setgroups  function is used to obtain	an explanation
       of an error returned by the setgroups(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.

       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.

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

       data    The original data, exactly as passed to the setgroups(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 buf-
       fer across all threads, and many	other functions	in this	library.

       Example:	 This  function	is intended to be used in a fashion similar to
       the following example:
	      if (setgroups(data_size, data) < 0)
	      {
		  int err = errno;
		  fprintf(stderr, "%s\n", explain_errno_setgroups(err,
		  data_size, data));
		  exit(EXIT_FAILURE);
	      }

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

   explain_message_setgroups
       void explain_message_setgroups(char *message, int message_size, size_t
       data_size, const	gid_t *data);

       The explain_message_setgroups function is used to obtain	an explanation
       of an error returned by the setgroups(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.

       message The location in which to	store the returned message. If a suit-
	       able 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.

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

       data    The original data, exactly as passed to the setgroups(2)	system
	       call.

       Example:	This function is intended to be	used in	a fashion  similar  to
       the following example:
	      if (setgroups(data_size, data) < 0)
	      {
		  char message[3000];
		  explain_message_setgroups(message, sizeof(message),
		  data_size, data);
		  fprintf(stderr, "%s\n", message);
		  exit(EXIT_FAILURE);
	      }

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

   explain_message_errno_setgroups
       void explain_message_errno_setgroups(char *message, int message_size,
       int errnum, size_t data_size, const gid_t *data);

       The explain_message_errno_setgroups function is used to obtain  an  ex-
       planation  of  an  error	returned by the	setgroups(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.

       message The location in which to	store the returned message. If a suit-
	       able 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.

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

       data    The original data, exactly as passed to the setgroups(2)	system
	       call.

       Example:	 This  function	is intended to be used in a fashion similar to
       the following example:
	      if (setgroups(data_size, data) < 0)
	      {
		  int err = errno;
		  char message[3000];
		  explain_message_errno_setgroups(message, sizeof(message),
		  err, data_size, data);
		  fprintf(stderr, "%s\n", message);
		  exit(EXIT_FAILURE);
	      }

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

SEE ALSO
       setgroups(2)
	       get/set list of supplementary group IDs

       explain_setgroups_or_die(3)
	       get/set list of supplementary group IDs and report errors

COPYRIGHT
       libexplain version 1.3
       Copyright (C) 2009 Peter	Miller

							  explain_setgroups(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_setgroups&sektion=3&manpath=FreeBSD+12.2-RELEASE+and+Ports>

home | help