Hex value 1A terminates <>

tekkie has asked for the wisdom of the Perl Monks concerning the following question:

Consider the code:

$count = 0;
open(FILE, 'test.txt');
while(<FILE>) { $count++; }
close FILE;
print "$count\n";
[download]

Where 'test.txt' resembles:

Arbitrary data
Arbitrary data
Arbitrary data
Arbitrary data
<SUB>
Arbitrary data
Arbitrary data
Arbitrary data
Arbitrary data
[download]

And where <SUB> is the SUBstitute character (Dec 26 Hex 1A Oct 032)

When running on WinNT 4.0 with ActivePerl build 631 the above code prints 4 when the SUB is there, and 9 if that line is left blank.

Has anyone encountered this problem before?
Is there a way to get the <> operator to read past the SUB char?

Edit by Petruchio Thu Jan 16 18:05:09 UTC 2003 - The ^Z character was causing trouble for certain browsers. It was replaced in two places with the string <SUB>, as chosen by the author.

Comment on Hex value 1A terminates <> Select or Download Code

Replies are listed 'Best First'.
Re: Hex value 1A terminates <> by jmcnamara (Monsignor) on Jan 13, 2003 at 14:19 UTC
You probably need to binmode the filehandle: `... open FILE, 'test.txt' or die "Error message here: $!\n"; binmode FILE; ...` [download] ASCII 26 is CTRL-Z on Windows and indicates the end of file. -- John.	[reply] [d/l]
Re: Hex value 1A terminates <> by derby (Abbot) on Jan 13, 2003 at 14:24 UTC
Just a guess here but SUB -> HEX 1A -> DEC 26 -> Ctrl-Z -> EOF marker for DOS files? What happens when you apply binmode? -derby	[reply]
Hex value 1A terminates <> by tekkie (Beadle) on Jan 13, 2003 at 14:26 UTC
binmode fixed the problem... thanks to all for helping me realizes what should've been obvious. I hate mondays...	[reply]
Re: Hex value 1A terminates <> by boo_radley (Parson) on Jan 13, 2003 at 14:18 UTC
That's an EOF character. Don't they teach control codes in school anymore? Oh, for the days when every computing book had a basic ASCII guide in the back. ~~anyway, I believe that you'll have to treat your source file as a binary, and use, e.g., read and seek on them.~~ No coffee, too early, mumble mumble, binmode, mumble mumble.	[reply]


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