Re: Accessing variables in an external hash without eval

Consider using a different storage format. I would choose JSON:

Format	Human readable	Arbitary structures (See update below)	8-bit clean	Version independant	Cross language	May execute code from file	Unexpected network access	Memory usage attack	Comments
Perl source code (generated manually or by tools like Data::Dumper)	kind of	yes	yes	mostly	no (only perl can parse Perl)	yes	by executable code	by executable code	yes
Storable	no	yes	yes	no (depends on Perl version, limited compatibility with other versions)	no	no	no	no	no
XML	yes	yes	no \x00 is illegal in XML, workaround like base64 required any amount of whitespace is often treated as a single space (CDATA required)	yes	yes	no	yes	yes	yes
YAML	yes (but with strange rules)	yes	yes	yes	yes	yes (may be disabled)	by executabe code	by executabe code	yes
JSON	yes	yes	yes	yes	yes	no	no	no	no (but some parsers allow Javascript or shell comments)
INI	yes	no, only HoH	no (escaping rules depend on reader and writer)	yes	yes	no	no	no	yes
CSV	yes	no, only 2D-Array (AoA)	no (escaping rules depend on reader and writer)	yes	yes	no	no	no	no

Updates:

"Arbitary structures" was not meant as arbitary as I wrote, thanks tobyink++. It should read something like "any mix of scalars, arrays, and hashes, without circular references, handles, code references, globs".

"Memory usage attack" means that either the parsed file uses significantly more memory (several orders of magnitute) than the file size, or parsing the file may execute code that allocates much memory.

"Unexpected network access" means either that parsing the file completely and correctly may require reading additional data from the internet, or parsing the file may execute code that accesses the network.

"8 bit clean" means that any binary data may be stored and fetched.

Added comments column

Added Data::Dumper

Alexander

--
Today I will gladly share my knowledge and experience, for there are no sweeter words than "I told you so". ;-)

Comment on Re: Accessing variables in an external hash without eval

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Re^2: Accessing variables in an external hash without eval by tobyink (Canon) on May 17, 2017 at 08:46 UTC
JSON cannot store "arbitrary structures". Not unless your definition of "arbitrary" is extremely limited. It can't contain cyclic references for example. Something like this can be represented in Perl code, Storable, YAML, and (using IDREF) probably in XML, but not JSON… `use strict; use warnings; use Data::Dumper qw(Dumper); use YAML::XS qw(Dump); my $data = do { my $child = {}; my $parent = { child => $child }; $child->{parent} = $parent; }; print "#### Perl ####\n"; print Dumper($data), "\n"; print "#### YAML ####\n"; print Dump($data), "\n";` [download]	[reply] [d/l]
Re^3: Accessing variables in an external hash without eval by afoken (Chancellor) on May 17, 2017 at 19:55 UTC
JSON cannot store "arbitrary structures". Not unless your definition of "arbitrary" is extremely limited. It can't contain cyclic references for example. You are right. Alexander -- Today I will gladly share my knowledge and experience, for there are no sweeter words than "I told you so". ;-)	[reply]


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