Re^2: pack() returns an unusable string

Guessing is sometimes fine, but the OP gave an entire and complete test script which you can examine and even run. If I make a small modification to the test script given we can test the theory:

# test.pl
use warnings;
$template = 'd<';
$nv = 2.4;
$p = pack $template, $nv;
$s = "'$p'";
print ">$s<\n";

system $^X, '-wle', "print unpack('H*', $s);";
[download]

prints:

>'333333@'<
3333333333330340
[download]

running a 64 bit build of 5.32. Note that there is an ETX character between the final 3 and the @ character, which, when you think about it, is the string that the unpack is showing us so for the success case there is a trailing @ and it isn't swallowing the trailing '.

Optimising for fewest key strokes only makes sense transmitting to Pluto or beyond

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Re^3: pack() returns an unusable string by tybalt89 (Monsignor) on May 26, 2021 at 23:29 UTC
OP said error only happens on D<, not d<, which doesn't run on my machine. However, here is a number for which the error occurs on 5.32 with d< `#!/usr/bin/perl -l use strict; use warnings; my $template = 'd<'; my $nv = 2.4; $nv = 4135; # NOTE errors for this number my $p = pack $template, $nv; my $s = "'$p'"; print ">$s<\n"; system $^X, '-wle', "print unpack('H*', $s);";` [download] Outputs: `>''°@'< Can't find string terminator "'" anywhere before EOF at -e line 1.` [download] which shows that my guess that the pack produces a single quote character is plausible.	[reply] [d/l] [select]
Re^4: pack() returns an unusable string by choroba (Cardinal) on May 27, 2021 at 09:54 UTC
In blead, it runs with `D<` and fails with `Can't find string terminator "'" anywhere before EOF at -e line 1.` [download] However, when I tried to output `say join ', ', map ord, split //, $p;` [download] I got `0, 152, 153, 153, 153, 153, 153, 153, 0, 64, 0, 0, 0, 0, 0, 0` [download] `map{substr$_->[0],$_->[1]\|\|0,1}[\\|\|{},3],[[]],[ref qr-1,-,-1],[{}],[sub{}^ARGV,3]`	[reply] [d/l] [select]