=over

=item eof FILEHANDLE

=item eof ()

=item eof

Returns 1 if the next read on FILEHANDLE will return end of file, or if
FILEHANDLE is not open.  FILEHANDLE may be an expression whose value
gives the real filehandle.  (Note that this function actually
reads a character and then C<ungetc()>s it, so isn't very useful in an
interactive context.)  Do not read from a terminal file (or call
C<eof(FILEHANDLE)> on it) after end-of-file is reached.  Filetypes such
as terminals may lose the end-of-file condition if you do.

An C<eof> without an argument uses the last file read as argument.
Using C<eof()> with empty parentheses is very different.  It indicates the pseudo file formed of
the files listed on the command line, i.e., C<eof()> is reasonable to
use inside a C<while (E<lt>E<gt>)> loop to detect the end of only the
last file.  Use C<eof(ARGV)> or eof without the parentheses to test
I<EACH> file in a while (E<lt>E<gt>) loop.  Examples:

    # reset line numbering on each input file
    while (<>) {
	next if /^\s*#/;	# skip comments 
	print "$.\t$_";
    } continue {
	close ARGV  if eof;	# Not eof()!
    }

    # insert dashes just before last line of last file
    while (<>) {
	if (eof()) {		# check for end of current file
	    print "--------------\n";
	    close(ARGV);	# close or break; is needed if we
				# are reading from the terminal
	}
	print;
    }

Practical hint: you almost never need to use C<eof> in Perl, because the
input operators return false values when they run out of data, or if there
was an error.

=back