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explain_setsid(3)	   Library Functions Manual	     explain_setsid(3)

NAME
       explain_setsid -	explain	setsid(2) errors

SYNOPSIS
       #include	<libexplain/setsid.h>
       const char *explain_setsid(void);
       const char *explain_errno_setsid(int errnum, void);
       void explain_message_setsid(char	*message, int message_size, void);
       void explain_message_errno_setsid(char *message,	int message_size, int
       errnum, void);

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

   explain_setsid
       const char *explain_setsid(void);

       The  explain_setsid function is used to obtain an explanation of	an er-
       ror returned by the setsid(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.

       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:
	      pid_t result = setsid();
	      if (result < 0)
	      {
		  fprintf(stderr, "%s\n", explain_setsid());
		  exit(EXIT_FAILURE);
	      }

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

   explain_errno_setsid
       const char *explain_errno_setsid(int errnum, void);

       The explain_errno_setsid	function is used to obtain an  explanation  of
       an  error  returned by the setsid(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.

       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:
	      pid_t result = setsid();
	      if (result < 0)
	      {
		  int err = errno;
		  fprintf(stderr, "%s\n", explain_errno_setsid(err, ));
		  exit(EXIT_FAILURE);
	      }

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

   explain_message_setsid
       void explain_message_setsid(char	*message, int message_size, void);

       The explain_message_setsid function is used to obtain an	explanation of
       an  error  returned by the setsid(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.

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

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

   explain_message_errno_setsid
       void explain_message_errno_setsid(char *message,	int message_size, int
       errnum, void);

       The explain_message_errno_setsid	function is used to obtain an explana-
       tion  of	 an error returned by the setsid(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.

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

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

SEE ALSO
       setsid(2)
	       creates a session and sets the process group ID

       explain_setsid_or_die(3)
	       creates	a session and sets the process group ID	and report er-
	       rors

COPYRIGHT
       libexplain version 1.3
       Copyright (C) 2011 Peter	Miller

							     explain_setsid(3)

NAME | SYNOPSIS | DESCRIPTION | SEE ALSO | COPYRIGHT

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