explain_futimes - explain futimes(3) errors
#include <libexplain/futimes.h>
const char *explain_futimes(int fildes, const struct timeval *tv);
const char *explain_errno_futimes(int errnum, int fildes, const struct timeval
*tv);
void explain_message_futimes(char *message, int message_size, int fildes, const
struct timeval *tv);
void explain_message_errno_futimes(char *message, int message_size, int errnum,
int fildes, const struct timeval *tv);
These functions may be used to obtain explanations for errors returned by the
futimes(3) system call.
const char *explain_futimes(int fildes, const struct timeval *tv);
The
explain_futimes function is used to obtain an explanation of an error
returned by the
futimes(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.
This function is intended to be used in a fashion similar to the following
example:
if (futimes(fildes, tv) < 0)
{
fprintf(stderr, "%s\n", explain_futimes(fildes, tv));
exit(EXIT_FAILURE);
}
The above code example is available pre‐packaged as the
explain_futimes_or_die(3) function.
- fildes
- The original fildes, exactly as passed to the futimes(3) system
call.
- tv
- The original tv, exactly as passed to the futimes(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
buffer across all threads, and many other functions in this library.
const char *explain_errno_futimes(int errnum, int fildes, const struct timeval
*tv);
The
explain_errno_futimes function is used to obtain an explanation of an
error returned by the
futimes(3) 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 (futimes(fildes, tv) < 0)
{
int err = errno;
fprintf(stderr, "%s\n", explain_errno_futimes(err, fildes, tv));
exit(EXIT_FAILURE);
}
The above code example is available pre‐packaged as the
explain_futimes_or_die(3) function.
- 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.
- fildes
- The original fildes, exactly as passed to the futimes(3) system
call.
- tv
- The original tv, exactly as passed to the futimes(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
buffer across all threads, and many other functions in this library.
void explain_message_futimes(char *message, int message_size, int fildes, const
struct timeval *tv);
The
explain_message_futimes function may be used to obtain an explanation
of an error returned by the
futimes(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.
This function is intended to be used in a fashion similar to the following
example:
if (futimes(fildes, tv) < 0)
{
char message[3000];
explain_message_futimes(message, sizeof(message), fildes, tv);
fprintf(stderr, "%s\n", message);
exit(EXIT_FAILURE);
}
The above code example is available pre‐packaged as the
explain_futimes_or_die(3) function.
- 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.
- fildes
- The original fildes, exactly as passed to the futimes(3) system
call.
- tv
- The original tv, exactly as passed to the futimes(3) system
call.
void explain_message_errno_futimes(char *message, int message_size, int errnum,
int fildes, const struct timeval *tv);
The
explain_message_errno_futimes function may be used to obtain an
explanation of an error returned by the
futimes(3) 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 (futimes(fildes, tv) < 0)
{
int err = errno;
char message[3000];
explain_message_errno_futimes(message, sizeof(message), err, fildes, tv);
fprintf(stderr, "%s\n", message);
exit(EXIT_FAILURE);
}
The above code example is available pre‐packaged as the
explain_futimes_or_die(3) function.
- 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 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.
- fildes
- The original fildes, exactly as passed to the futimes(3) system
call.
- tv
- The original tv, exactly as passed to the futimes(3) system
call.
- futimes(3)
- change file timestamps
- explain_futimes_or_die(3)
- change file timestamps and report errors
libexplain version 1.3
Copyright (C) 2008 Peter Miller