Another way to do this?

[Trebor A. Rude]

In an effort learn Perl, I was converting some of my smaller C++ programs to
Perl scripts. I had one program which printed out the bytes of an integer
as characters (so 0x616263 would be "abc"). I've got a Perl solution, but
for some reason it seems unnecessarily complicated. Is there a better way
to accomplish the same thing as the script below? I keep thinking that pack
or unpack can do it, but darned if I can figure out how.

#!/usr/bin/perl -w

use strict;

for (@ARGV)
{
$_ = oct if /^0/;
my @bytes;
do { unshift @bytes, $_ & 0xFF; } while (($_ >>= 8) > 0);
print chr for @bytes;
print "\n";
}

 

[Tassilo v. Parseval]

Also sprach Trebor A. Rude:

In an effort learn Perl, I was converting some of my smaller C++ programs to
Perl scripts. I had one program which printed out the bytes of an integer
as characters (so 0x616263 would be "abc"). I've got a Perl solution, but
for some reason it seems unnecessarily complicated. Is there a better way
to accomplish the same thing as the script below? I keep thinking that pack
or unpack can do it, but darned if I can figure out how.

Yes, pack() and unpack() are quite suitable for that.

#!/usr/bin/perl -w

use strict;

for (@ARGV)
{
$_ = oct if /^0/;
my @bytes;
do { unshift @bytes, $_ & 0xFF; } while (($_ >>= 8) > 0);
print chr for @bytes;
print "\n";
}

In Perl this can be condensed into a one-liner:

perl -le 'print unpack "A*", pack "H*", $_ for @ARGV' 0x616263 0x626364
abc
bcd

Or as a real script:

print ((unpack "A*", pack "H*", $_), "\n") for @ARGV;

See 'perldoc -f pack'.

Tassilo