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explain_lutimes(3) Library Functions Manual explain_lutimes(3)

NAME

explain_lutimes - explain lutimes(3) errors

SYNOPSIS

#include <libexplain/lutimes.h>

const char *explain_lutimes(const char *pathname, const struct timeval *data);
const char *explain_errno_lutimes(int errnum, const char *pathname, const struct timeval *data);
void explain_message_lutimes(char *message, int message_size, const char *pathname, const struct timeval *data);
void explain_message_errno_lutimes(char *message, int message_size, int errnum, const char *pathname, const struct timeval *data);

DESCRIPTION

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

explain_lutimes

const char *explain_lutimes(const char *pathname, const struct timeval *data);

The explain_lutimes function is used to obtain an explanation of an error returned by the lutimes(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.

The original pathname, exactly as passed to the lutimes(3) system call.
The original data, exactly as passed to the lutimes(3) system call.
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.

Example: This function is intended to be used in a fashion similar to the following example:


if (lutimes(pathname, data) < 0)
{

fprintf(stderr, "%s\n", explain_lutimes(pathname, data));

exit(EXIT_FAILURE); }

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

explain_errno_lutimes

const char *explain_errno_lutimes(int errnum, const char *pathname, const struct timeval *data);

The explain_errno_lutimes function is used to obtain an explanation of an error returned by the lutimes(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 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.
The original pathname, exactly as passed to the lutimes(3) system call.
The original data, exactly as passed to the lutimes(3) system call.
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.

Example: This function is intended to be used in a fashion similar to the following example:


if (lutimes(pathname, data) < 0)
{

int err = errno;

fprintf(stderr, "%s\n", explain_errno_lutimes(err, pathname, data));

exit(EXIT_FAILURE); }

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

explain_message_lutimes

void explain_message_lutimes(char *message, int message_size, const char *pathname, const struct timeval *data);

The explain_message_lutimes function is used to obtain an explanation of an error returned by the lutimes(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.

The location in which to store the returned message. If a suitable message return buffer is supplied, this function is thread safe.
The size in bytes of the location in which to store the returned message.
The original pathname, exactly as passed to the lutimes(3) system call.
The original data, exactly as passed to the lutimes(3) system call.

Example: This function is intended to be used in a fashion similar to the following example:


if (lutimes(pathname, data) < 0)
{

char message[3000];
explain_message_lutimes(message, sizeof(message), pathname, data);


fprintf(stderr, "%s\n", message);
exit(EXIT_FAILURE); }

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

explain_message_errno_lutimes

void explain_message_errno_lutimes(char *message, int message_size, int errnum, const char *pathname, const struct timeval *data);

The explain_message_errno_lutimes function is used to obtain an explanation of an error returned by the lutimes(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 location in which to store the returned message. If a suitable message return buffer is supplied, this function is thread safe.
The size in bytes of the location in which to store the returned message.
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.
The original pathname, exactly as passed to the lutimes(3) system call.
The original data, exactly as passed to the lutimes(3) system call.

Example: This function is intended to be used in a fashion similar to the following example:


if (lutimes(pathname, data) < 0)
{

int err = errno;
char message[3000];
explain_message_errno_lutimes(message, sizeof(message), err, pathname, data);


fprintf(stderr, "%s\n", message);
exit(EXIT_FAILURE); }

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

SEE ALSO

lutimes(3)
modify file timestamps
explain_lutimes_or_die(3)
modify file timestamps and report errors

COPYRIGHT

libexplain version 1.4
Copyright (C) 2013 Peter Miller