The explain_gettimeofday function is used to obtain an
explanation of an error returned by the gettimeofday(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 following example:
The original tv, exactly as passed to the gettimeofday(2) system call.
tz
The original tz, exactly as passed to the gettimeofday(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 buffer across all threads, and many other
functions in this library.
The explain_errno_gettimeofday function
is used to obtain an explanation of an error returned by
the gettimeofday(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 following example:
if (gettimeofday(tv, tz) < 0)
{
int err = errno;
fprintf(stderr, "%s\n", explain_errno_gettimeofday(err, tv, tz));
exit(EXIT_FAILURE);
}
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.
tv
The original tv, exactly as passed to the gettimeofday(2) system call.
tz
The original tz, exactly as passed to the gettimeofday(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 buffer across all threads, and many other
functions in this library.
The explain_message_gettimeofday
function may be used to obtain an explanation of an error
returned by the
gettimeofday(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 following example:
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.
tv
The original tv, exactly as passed to the gettimeofday(2) system call.
tz
The original tz, exactly as passed to the gettimeofday(2) system call.
explain_message_errno_gettimeofday
void explain_message_errno_gettimeofday(char *message, int message_size,
int errnum, struct timeval *tv, struct timezone *tz);
The explain_message_errno_gettimeofday
function may be used to obtain an explanation of an error
returned by the
gettimeofday(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 following example:
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 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.
tv
The original tv, exactly as passed to the gettimeofday(2) system call.
tz
The original tz, exactly as passed to the gettimeofday(2) system call.