Re^4: Displaying bit-vectors with Most Significant Bits to the left?

But vec's approach might provide reproducible results on different architectures.

Each of the snippets I posted produces the same output on both little-endian and big-endian machines.

With pack, you say what you want, and you get it. It's far cleaner than being told what you're going to get —sometimes LE, sometimes BE, based on the size of the third arg— and having to work around that.

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Re^5: Displaying bit-vectors with Most Significant Bits to the left? by LanX (Saint) on Jan 06, 2020 at 14:33 UTC
> Each of the snippets I posted produces the same output on both little-endian and big-endian machines I believe you, but how do you reliably check the output? And what does "same output" exactly mean? I did machine programming on big-endian architectures, I don't know what to trust anymore. Do I need to check with Devel::Peek to be sure? Cheers Rolf _{(addicted to the Perl Programming Language :) Wikisyntax for the Monastery FootballPerl is like chess, only without the dice}	[reply]
Re^6: Displaying bit-vectors with Most Significant Bits to the left? by ikegami (Patriarch) on Jan 07, 2020 at 18:47 UTC
I believe you, but how do you reliably check the output? Whether using `vec`, `pack` or some other means, there are two ways: Reading the documentation, or testing experimentally on the appropriate machines. And what does "same output" exactly mean? For the code in Re: Displaying bit-vectors with Most Significant Bits to the left?, the topic was producing `0000011100000101` from `$m0`. For the code in Re^2: Displaying bit-vectors with Most Significant Bits to the left?, the topic was producing a string consisting of the byte 0b00000111 followed by the byte 0b00000101. I did machine programming on big-endian architectures, I don't know what to trust anymore. Do I need to check with Devel::Peek to be sure? Check what? If `pack` or `vec` produced the expected strings? `Devel::Peek::Dump` would be too noisy. I'd use one of the following: `sprintf "%v02X", $bytes unpack 'H', $bytes` [download] For example, `$ perl -e' for my $format (qw( n v )) { my $bytes = pack($format, 0x1234); CORE::say sprintf "%v02X", $bytes; CORE::say unpack "H", $bytes; } ' 12.34 1234 34.12 3412` [download]	[reply] [d/l] [select]