NAME
explain_opendir - explain opendir(3) errors
SYNOPSIS
const char *explain_opendir(const char *pathname);
const char *explain_errno_opendir(int errnum, const char *pathname);
int errnum, const char *pathname);
void explain_message_opendir(char *message, int message_size,
void explain_message_errno_opendir(char *message, int message_size,
const char *pathname);
DESCRIPTION
These functions may be used to explain opendir(3) errors.
explain_opendir
const char *explain_opendir(const char *pathname);
The explain_opendir function is used to obtain an explanation of an
error returned by the opendir(3) function. 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:
DIR *dp = opendir(pathname);
if (!dp)
{
fprintf(stderr, "%s\n", explain_opendir(pathname));
exit(EXIT_FAILURE);
}
pathname
The original pathname, exactly as passed to the opendir(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.
explain_errno_opendir
const char *explain_errno_opendir(int errnum, const char *pathname);
int errnum, const char *pathname);
The explain_errno_opendir function is used to obtain an explanation of
an error returned by the opendir(3) function. 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:
DIR *dp = opendir(pathname);
if (!dp)
{
int errnum = errno;
const char *message = explain_errno_opendir(errnum, pathname);
fprintf(stderr, "%s\n", message);
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.
pathname
The original pathname, exactly as passed to the opendir(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.
explain_message_opendir
void explain_message_opendir(char *message, int message_size, const
char *pathname);
The explain_message_opendir function is used to obtain an explanation
of an error returned by the opendir(3) function. 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:
DIR *dp = opendir(pathname);
if (!dp)
{
char message[3000];
explain_message_opendir(message, sizeof(message), pathname);
fprintf(stderr, "%s\n", message);
exit(EXIT_FAILURE);
}
message The location in which to store the returned message. Because a
message return buffer has been supplied, this function is thread safe
if the buffer is thread safe.
message_size
The size in bytes of the location in which to store the
returned message.
pathname
The original pathname, exactly as passed to the opendir(3)
system call.
explain_message_errno_opendir
void explain_message_errno_opendir(char *message, int message_size,
const char *pathname);
The explain_message_errno_opendir function is used to obtain an
explanation of an error returned by the opendir(3) function. 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:
DIR *dp = opendir(pathname);
if (!dp);
{
int err = errno;
char message[3000];
explain_message_errno_opendir(message, sizeof(message), err,
pathname);
fprintf(stderr, ’%s\n’, message);
exit(EXIT_FAILURE);
}
message The location in which to store the returned message.
Because a message return buffer has been supplied, this
function is thread safe if the buffer 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.
pathname
The original pathname, exactly as passed to the
opendir(3) system call.
COPYRIGHT
libexplain version
Copyright (C) 2008 Peter Miller
AUTHOR
Written by Peter Miller <pmiller@opensource.org.au>
3()