Provided by: libexplain-dev_1.4.D001-13_amd64 
NAME
explain_lchown - explain lchown(2) errors
SYNOPSIS
#include <libexplain/lchown.h>
const char *explain_lchown(const char *pathname, int owner, int group);
const char *explain_errno_lchown(int errnum, const char *pathname, int owner, int group);
void explain_message_lchown(char *message, int message_size, const char *pathname, int owner, int group);
void explain_message_errno_lchown(char *message, int message_size, int errnum, const char *pathname, int
owner, int group);
DESCRIPTION
These functions may be used to obtain explanations for errors returned by the lchown(2) system call.
explain_lchown
const char *explain_lchown(const char *pathname, int owner, int group);
The explain_lchown function is used to obtain an explanation of an error returned by the lchown(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 (lchown(pathname, owner, group) < 0)
{
fprintf(stderr, "%s\n", explain_lchown(pathname, owner, group));
exit(EXIT_FAILURE);
}
pathname
The original pathname, exactly as passed to the lchown(2) system call.
owner The original owner, exactly as passed to the lchown(2) system call.
group The original group, exactly as passed to the lchown(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_lchown
const char *explain_errno_lchown(int errnum, const char *pathname, int owner, int group);
The explain_errno_lchown function is used to obtain an explanation of an error returned by the lchown(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 (lchown(pathname, owner, group) < 0)
{
int err = errno;
fprintf(stderr, "%s\n", explain_errno_lchown(err,
pathname, owner, group));
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 lchown(2) system call.
owner The original owner, exactly as passed to the lchown(2) system call.
group The original group, exactly as passed to the lchown(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_lchown
void explain_message_lchown(char *message, int message_size, const char *pathname, int owner, int group);
The explain_message_lchown function may be used to obtain an explanation of an error returned by the
lchown(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 (lchown(pathname, owner, group) < 0)
{
char message[3000];
explain_message_lchown(message, sizeof(message),
pathname, owner, group);
fprintf(stderr, "%s\n", message);
exit(EXIT_FAILURE);
}
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.
pathname
The original pathname, exactly as passed to the lchown(2) system call.
owner The original owner, exactly as passed to the lchown(2) system call.
group The original group, exactly as passed to the lchown(2) system call.
explain_message_errno_lchown
void explain_message_errno_lchown(char *message, int message_size, int errnum, const char *pathname, int
owner, int group);
The explain_message_errno_lchown function may be used to obtain an explanation of an error returned by
the lchown(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 (lchown(pathname, owner, group) < 0)
{
int err = errno;
char message[3000];
explain_message_errno_lchown(message, sizeof(message), err,
pathname, owner, group);
fprintf(stderr, "%s\n", message);
exit(EXIT_FAILURE);
}
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.
pathname
The original pathname, exactly as passed to the lchown(2) system call.
owner The original owner, exactly as passed to the lchown(2) system call.
group The original group, exactly as passed to the lchown(2) system call.
SEE ALSO
lchown(2)
change ownership of a file
explain_lchown_or_die(3)
change ownership of a file and report errors
COPYRIGHT
libexplain version 1.4
Copyright (C) 2008 Peter Miller
explain_lchown(3)