NAME
explain_lstat - explain lstat(3) errors
SYNOPSIS
#include <libexplain/lstat.h>
const char *explain_lstat(const char *pathname, const struct stat
*buf);
void explain_message_lstat(char *message, int message_size, const char
*pathname, const struct stat *buf);
const char *explain_errno_lstat(int errnum, const char *pathname, const
struct stat *buf);
void explain_message_errno_lstat(char *message, int message_size, int
errnum, const char *pathname, const struct stat *buf);
DESCRIPTION
These functions may be used to obtains explanations for lstat(2)
errors.
explain_lstat
const char *explain_lstat(const char *pathname, const struct stat
*buf);
The explain_lstat function is used to obtain an explanation of an error
returned by the lstat(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 (lstat(pathname, &buf) < 0)
{
fprintf(stderr, ’%s0, explain_lstat(pathname, &buf));
exit(EXIT_FAILURE);
}
pathname
The original pathname, exactly as passed to the lstat(2) system
call.
buf The original buf, exactly as passed to the lstat(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_lstat
"const char *explain_errno_lstat(int errnum, const char *pathname,
const struct stat *buf);
The explain_errno_lstat function is used to obtain an explanation of an
error returned by the lstat(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 (lstat(pathname, &buf) < 0)
{
int err = errno;
fprintf(stderr, ’%s0, explain_errno_lstat(err, pathname, &buf));
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 lstat(2) system
call.
buf The original buf, exactly as passed to the lstat(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_lstat
void explain_message_lstat(char *message, int message_size, const char
*pathname, const struct stat *buf);
The explain_message_lstat function is used to obtain an explanation of
an error returned by the lstat(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 (lstat(pathname, &buf) < 0)
{
char message[3000];
explain_message_lstat(message, sizeof(message), pathname, &buf);
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 lstat(2) system
call.
buf The original buf, exactly as passed to the lstat(2) system
call.
explain_message_errno_lstat
void explain_message_errno_lstat(char *message, int message_size, int
errnum, const char *pathname, const struct stat *buf);
The explain_message_errno_lstat function is used to obtain an
explanation of an error returned by the lstat(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 (lstat(pathname, &buf) < 0)
{
int err = errno;
char message[3000];
explain_message_errno_lstat(message, sizeof(message), err,
pathname, &buf);
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 lstat(2) system
call.
buf The original buf, exactly as passed to the lstat(2) system
call.
COPYRIGHT
libexplain version
Copyright (C) 2008 Peter Miller
AUTHOR
Written by Peter Miller <pmiller@opensource.org.au>
explain_lstat(3)