Problem Reading File when Name contains character numbers 63 ("?"),164, 186, 243, 248

I am trying to access all of the files in a directory, using
$a=opendir($dir) ; while ($file=readdir($a)) and
$b=file_get_contents($dir."/".$file). However, when $file contains
characters 63 ("?"), 164, 186, 243 or 248 $b is "". I tried
substituting each of the characters chr(0 to 255) for a single "?" in
file names but none of the resulting names created a value for $b
other than "".

How do I read these file contents?

P -

Here are suggestions that I have received from various sources and am
trying myself (to the extent that I know what he's talking about):

1. ? is a special symbol that shouldn't be used within a file name.
As for other symbols - 164 might require you to set a proper non-
unicode symbol table, and other symbols are just garbage, as far as i
see the ASCII table.

2. I think this is a trouble that has to do with the file system you
are using, some file systems requires prepending "\\?\" to the file
name to be able to get around it's normal file name checks.

3. If your code is working for normal files, odds are good that you
need to escape these special characters before you can read them.
Escaping these is dependent on your operating system, so the character
you'll use depends on the system you're running. If your system uses
the backslash to escape characters (ie, Linux), try writing these
characters with a leading backspace, ie:
foreach(glob("$dir/*") as $eachFile) {
$eachFile = preg_replace('/['.chr(63).chr(164).chr(186).']/', '\\\
\\\0', $eachFile);
print "$eachFile : ".strlen(file_get_contents($eachFile))."\n"; }

4. Question mark is illegal in file names on both Windows and Unix...
It is illegal on Windows, but it is quite valid in Unix. Forward
slash / is the only character that is invalid in a Unix file name.
Try replacing "?" with "%3F"

5. Try this one, just to explore some. echo(basename
($PHP_SELF)."<br>"); // returnes filename.php

6. You will need to construct a routine to preface the file read or to
actually dig into the PHP library and modify the base module for that
read.

7. Could we copy the original file to a standard name, or rename it,
without causing an error? I will look and see what ways the different
functions have of handling filenames and
pathing...