Current Perl documentation can be found at perldoc.perl.org.

Here is our local, out-dated (pre-5.6) version:

Normally perl ignores trailing blanks in filenames, and interprets certain leading characters (or a trailing ``|'') to mean something special. To avoid this, you might want to use a routine like this. It makes incomplete pathnames into explicit relative ones, and tacks a trailing null byte on the name to make perl leave it alone:

    sub safe_filename {
        local $_  = shift;
        return m#^/#
                ? "$_\0"
                : "./$_\0";
    }

    $fn = safe_filename("<<<something really wicked   ");
    open(FH, "> $fn") or "couldn't open $fn: $!";

You could also use the sysopen() function (see sysopen).