in reply to Re: How do I read a 24 bit integer?
in thread How do I read a 24 bit integer?

I think I understand that, but a couple of curves:

1. How would I handle little endian data? Would it work correctly with no offset?

2. The real data file (of course) is somewhat more complicated. It has several consecutive 24 bit integers. So how would I read and unpack say four at a time?

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Re^3: How do I read a 24 bit integer?
by JavaFan (Canon) on Jan 01, 2010 at 17:15 UTC
    1. Little endian would have 8 trailing 0 bits, wouldn't it? I'm sure you'll be able to add a NUL byte to a string.
    2. How about reading them into four variables, and prepending them with NUL bytes?
[reply]
      Finally understanding this a bit, but it seems like I have one more problem.

      First, my code: 

      read FILE, $myinput, 12;
my($var1, $var2, $var3, $var4) = unpack('A3A3A3A3', $myinput);
$var1 = unpack ('N', "\x00" . $var1);
$var2 = unpack ('N', "\x00" . $var2);
$var3 = unpack ('N', "\x00" . $var3);
$var4 = unpack ('N', "\x00" . $var4);
print "$var1\n";
print "$var2\n";
print "$var3\n";
print "$var4\n";

      [download]
      The problem is that some of these values are legitimately zero, and when I try to print them, I get: 
      Use of uninitialized value in concatenation (.) or string at myscript.
+pl line 20.

      [download]
      What did I miss to allow zeroes?
[reply]
[d/l]
[select]
        Are you sure you actually read 12 bytes? Because it seems one of your variables wasn't set by the unpack (probably the $var4).
[reply]

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