Provided by: explain_0.52.D002-1_amd64 
NAME
explain_chmod - explain chmod(2) errors
SYNOPSIS
#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:
if (chmod(pathname, mode) < 0)
{
fprintf(stderr, '%s0, explain_chmod(pathname, mode));
exit(EXIT_FAILURE);
}
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_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, '%s0, 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:
if (chmod(pathname, mode) < 0)
{
char message[3000];
explain_message_chmod(message, sizeof(message), pathname, mode);
fprintf(stderr, '%s0, 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.
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, '%s0, 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 0.52
Copyright (C) 2008 Peter Miller
AUTHOR
Written by Peter Miller <pmiller@opensource.org.au>
explain_chmod(3)