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

FreeBSD Manual Pages

  
 
  

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

NAME
       explain_sleep - explain sleep(3)	errors

SYNOPSIS
       #include	<libexplain/sleep.h>
       const char *explain_sleep(unsigned int seconds);
       const char *explain_errno_sleep(int errnum, unsigned int	seconds);
       void explain_message_sleep(char *message, int message_size, unsigned
       int seconds);
       void explain_message_errno_sleep(char *message, int message_size, int
       errnum, unsigned	int seconds);

DESCRIPTION
       These  functions	may be used to obtain explanations for errors returned
       by the sleep(3) system call.

   explain_sleep
       const char *explain_sleep(unsigned int seconds);

       The explain_sleep function is used to obtain an explanation of an error
       returned	 by  the sleep(3) system call. The least the message will con-
       tain is the value of strerror(errno), but usually it will do much  bet-
       ter, and	indicate the underlying	cause in more detail.

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

       seconds The original seconds, exactly as	passed to the sleep(3)	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:
	      unsigned int result = sleep(seconds);
	      if (result < 0)
	      {
		  fprintf(stderr, "%s\n", explain_sleep(seconds));
		  exit(EXIT_FAILURE);
	      }

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

   explain_errno_sleep
       const char *explain_errno_sleep(int errnum, unsigned int	seconds);

       The explain_errno_sleep function	is used	to obtain an explanation of an
       error  returned by the sleep(3) 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.

       seconds The  original seconds, exactly as passed	to the sleep(3)	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:
	      unsigned int result = sleep(seconds);
	      if (result < 0)
	      {
		  int err = errno;
		  fprintf(stderr, "%s\n", explain_errno_sleep(err, seconds));
		  exit(EXIT_FAILURE);
	      }

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

   explain_message_sleep
       void explain_message_sleep(char *message, int message_size, unsigned
       int seconds);

       The explain_message_sleep function is used to obtain an explanation  of
       an  error  returned  by the sleep(3) 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.

       seconds The  original seconds, exactly as passed	to the sleep(3)	system
	       call.

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

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

   explain_message_errno_sleep
       void explain_message_errno_sleep(char *message, int message_size, int
       errnum, unsigned	int seconds);

       The  explain_message_errno_sleep	function is used to obtain an explana-
       tion of an error	returned by the	sleep(3) 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.

       seconds The  original seconds, exactly as passed	to the sleep(3)	system
	       call.

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

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

SEE ALSO
       sleep(3)
	       Sleep for the specified number of seconds

       explain_sleep_or_die(3)
	       Sleep for the specified number of seconds and report errors

COPYRIGHT
       libexplain version 1.3
       Copyright (C) 2013 Peter	Miller

							      explain_sleep(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_sleep&sektion=3&manpath=FreeBSD+12.2-RELEASE+and+Ports>

home | help