NAME
explain_rename - explain rename(2) errors
SYNOPSIS
#include <libexplain/rename.h>
const char *explain_rename(const char *oldpath, const char *newpath);
const char *explain_errno_rename(int errnum, const char *oldpath, const
char *newpath);
void explain_message_rename(char *message, int message_size, const char
*oldpath, const char *newpath);
void explain_message_errno_rename(char *message, int message_size, int
errnum, const char *oldpath, const char *newpath);
DESCRIPTION
The functions declared in the <libexplain/rename.h> include file may be
used to explain errors returned by the rename(2) system call.
explain_rename
const char *explain_rename(const char *oldpath, const char *newpath);
The explain_rename function is used to obtain an explanation of an
error returned by the rename(2) 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:
if (rename(oldpath, rewpath) < 0)
{
fprintf(stderr, "%s\n", explain_rename(oldpath, newpath));
exit(EXIT_FAILURE);
}
oldpath The original oldpath, exactly as passed to the rename(2) system
call.
newpath The original newpath, exactly as passed to the rename(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_rename
const char *explain_errno_rename(int errnum, const char *oldpath, const
char *newpath);
The explain_errno_rename function is used to obtain an explanation of
an error returned by the rename(2) 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:
if (rename(oldpath, newpath) < 0)
{
int err = errno;
fprintf(stderr, "%s\n", explain_errno_rename(err, oldpath,
newpath));
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.
oldpath The original oldpath, exactly as passed to the rename(2) system
call. newpath The original newpath, exactly as passed to the
rename(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_rename
void explain_message_rename(char *message, int message_size, const char
*oldpath, const char *newpath);
The explain_message_rename function is used to obtain an explanation of
an error returned by the rename(2) 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:
if (rename(oldpath, newpath) < 0)
{
char message[3000];
explain_message_rename(message, sizeof(message), oldpath,
newpath);
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.
oldpath The original oldpath, exactly as passed to the rename(2) system
call.
newpath The original newpath, exactly as passed to the rename(2) system
call.
explain_message_errno_rename
void explain_message_errno_rename(char *message, int message_size, int
errnum, const char *oldpath, const char *newpath);
The explain_message_errno_rename function is used to obtain an
explanation of an error returned by the rename(2) 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:
if (rename(oldpath, newpath) < 0)
{
int err = errno;
char message[3000];
explain_message_errno_rename(message, sizeof(message), err,
oldpath, newpath);
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, given a thread safe buffer.
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.
oldpath The original oldpath, exactly as passed to the rename(2) system
call.
newpath The original newpath, exactly as passed to the rename(2) system
call.
COPYRIGHT
libexplain version
Copyright (C) 2008 Peter Miller
AUTHOR
Written by Peter Miller <pmiller@opensource.org.au>
explain_rename(3)