#include <libexplain/chmod.h>
const char *explain_chmod(const char *pathname, int mode);
const char *explain_errno_chmod(int errnum, const char *pathname, int mode);
void explain_message_chmod(char *message, int message_size,
const char *pathname, int mode);
void explain_message_errno_chmod(char *message, int message_size,
int errnum, const char *pathname, int mode);
DESCRIPTION
These functions may be used to otain
explanations for chmod(2) errors.
explain_chmod
const char *explain_chmod(const char *pathname, int mode);
The explain_chmod function is used to obtain an explanation of an
error returned by the chmod(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 pathname, exactly as passed to the chmod(2) system call.
mode
The original mode, exactly as passed to the chmod(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.
explain_errno_chmod
const char *explain_errno_chmod(int errnum, const char *pathname, int mode);
The explain_errno_chmod function is used to obtain an explanation
of an error returned by the chmod(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 (chmod(pathname) < 0)
{
int err = errno;
fprintf(stderr, '%s, explain_errno_chmod(err, pathname));
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 chmod(2) system call.
mode
The original mode, exactly as passed to the chmod(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.
explain_message_chmod
void explain_message_chmod(char *message, int message_size,
const char *pathname, int mode);
The explain_message_chmod function is used to obtain an explanation
of an error returned by the chmod(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. Because a message
return buffer has been supplied, this function 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 chmod(2) system call.
mode
The original mode, exactly as passed to the chmod(2) system call.
explain_message_errno_chmod
void explain_message_errno_chmod(char * message, int message_size,
int errnum, const char *pathname, int mode);
The explain_message_errno_chmod function is used to obtain
an explanation of an error returned by the chmod(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 (chmod(pathname) < 0)
{
int err = errno;
char message[3000];
explain_message_errno_chmod(message, sizeof(message), err,
pathname);
fprintf(stderr, '%s, 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.
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 chmod(2) system call.
mode
The original mode, exactly as passed to the chmod(2) system call.
COPYRIGHT
libexplain version 0.37
Copyright (C) 2008 Peter Miller