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explain_adjtimex(3)	    Library Functions Manual	     explain_adjtimex(3)

NAME
     explain_adjtimex - explain adjtimex(2) errors

SYNOPSIS
     #include <libexplain/adjtimex.h>
     const char *explain_adjtimex(struct timex *data);
     const char *explain_errno_adjtimex(int errnum, struct timex *data);
     void explain_message_adjtimex(char *message, int message_size, struct timex
     *data);
     void explain_message_errno_adjtimex(char *message, int message_size, int
     errnum, struct timex *data);

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

   explain_adjtimex
     const char *explain_adjtimex(struct timex *data);

     The explain_adjtimex function is used to obtain an explanation of an  error
     returned by the adjtimex(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  de-
     coded.

     data    The  original  data,  exactly  as	passed to the adjtimex(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 ar-
	     gument list.  This will be overwritten by the next call to any lib-
	     explain 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.

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

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

   explain_errno_adjtimex
     const char *explain_errno_adjtimex(int errnum, struct timex *data);

     The  explain_errno_adjtimex function is used to obtain an explanation of an
     error returned by the adjtimex(2) system call.  The least the message  will
     contain  is  the value of strerror(errno), but usually it will do much bet-
     ter, 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 neces-
	     sary if you need to call any code between the system call to be ex-
	     plained  and  this function, because many libc functions will alter
	     the value of errno.

     data    The original data, exactly as  passed  to	the  adjtimex(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  ar-
	     gument list.  This will be overwritten by the next call to any lib-
	     explain 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.

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

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

   explain_message_adjtimex
     void explain_message_adjtimex(char *message, int message_size, struct timex
     *data);

     The explain_message_adjtimex function is used to obtain an  explanation  of
     an  error	returned  by the adjtimex(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 de-
     coded.

     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.

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

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

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

   explain_message_errno_adjtimex
     void explain_message_errno_adjtimex(char *message, int message_size, int
     errnum, struct timex *data);

     The  explain_message_errno_adjtimex  function is used to obtain an explana-
     tion of an error returned by the adjtimex(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	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 ex-
	     plained  and  this function, because many libc functions will alter
	     the value of errno.

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

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

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

SEE ALSO
     adjtimex(2)
	     tune kernel clock

     explain_adjtimex_or_die(3)
	     tune kernel clock and report errors

COPYRIGHT
     libexplain version 1.3
     Copyright (C) 2009 Peter Miller

							     explain_adjtimex(3)

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