Re: How do I read a 24 bit integer?

Sorry. I have to repeat this here. It seems I can't go down enough levels to read even my own last reply. As I said, this code:

#!/usr/bin/perl -w
use strict;

my $myinput="\x00\x00\x00\x00\x00\x00\x01\x02\x03\x04\x05\x06";
my($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]

produces:

Use of uninitialized value in concatenation (.) or string at ./test2.p
+l line 10.

Use of uninitialized value in concatenation (.) or string at ./test2.p
+l line 11.

66051
263430
[download]

When I would expect to see:

0
0
66051
263430
[download]

Comment on Re: How do I read a 24 bit integer? Select or Download Code

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Re^2: How do I read a 24 bit integer? by juster (Friar) on Jan 03, 2010 at 18:43 UTC
Click on a note's title in order to show the responses beneath it. Pack mojo is always interesting and very deep! I found this in the pack manpage in order to explain your problem and BrowserUK's solution: When unpacking, "A" strips trailing whitespace and nulls, "Z" strips everything after the first null, and "a" returns data verbatim.	[reply]