Communities

Writing
Writing
Codidact Meta
Codidact Meta
The Great Outdoors
The Great Outdoors
Photography & Video
Photography & Video
Scientific Speculation
Scientific Speculation
Cooking
Cooking
Electrical Engineering
Electrical Engineering
Judaism
Judaism
Languages & Linguistics
Languages & Linguistics
Software Development
Software Development
Mathematics
Mathematics
Christianity
Christianity
Code Golf
Code Golf
Music
Music
Physics
Physics
Linux Systems
Linux Systems
Power Users
Power Users
Tabletop RPGs
Tabletop RPGs
Community Proposals
Community Proposals
tag:snake search within a tag
answers:0 unanswered questions
user:xxxx search by author id
score:0.5 posts with 0.5+ score
"snake oil" exact phrase
votes:4 posts with 4+ votes
created:<1w created < 1 week ago
post_type:xxxx type of post
Search help
Notifications
Mark all as read See all your notifications »
Q&A

Welcome to Software Development on Codidact!

Will you help us build our independent community of developers helping developers? We're small and trying to grow. We welcome questions about all aspects of software development, from design to code to QA and more. Got questions? Got answers? Got code you'd like someone to review? Please join us.

How do I choose the correct Perl module from these variations?

+3
−1

When looking for Perl modules to handle JSON strings and/or documents, I found JSON::PP and JSON::XS. The documentation of JSON::PP says it is compatible with JSON::XS.

  1. What do these suffixes mean?
  2. Which one should I use and why?
History
Why does this post require moderator attention?
You might want to add some details to your flag.
Why should this post be closed?

0 comment threads

2 answers

+0
−0

Realistically in 2024, you should be using Cpanel::JSON::XS, and JSON::MaybeXS. Cpanel::JSON::XS is by far the best JSON implementation for Perl, but not every platform will have it, so you can use JSON::MaybeXS to include the "best" JSON implementation for the current platform. Which could be any of Cpanel::JSON::XS (best), JSON::XS, JSON::PP, or JSON.

History
Why does this post require moderator attention?
You might want to add some details to your flag.

0 comment threads

+6
−2

Perl modules sometimes have different implementations. The ::PP suffix means it's a "Pure Perl" implementation, where portability is the goal. The ::XS suffix is for the C-based implementation, where speed is the goal. Finally, JSON is just the top-level module itself, i.e. the one you actually use.

This site has a good description of their differences, but to quote:

JSON

JSON.pm is a wrapper around JSON::PP and JSON::XS - it also does a bunch of moderately crazy things for compatibility reasons, including extra shim code for very old perls [...]

JSON::PP

This is the standard pure perl implementation, and if you're not performance dependent, there's nothing wrong with using it directly [...]

JSON::XS

Ridiculously fast JSON implementation in C. Absolutely wonderful [...]

Just installing the top-level JSON module should work. The part about compatibility just means that both do the same thing, i.e. you should get the same output from both.

I installed the Perl JSON module a few years ago on a RHEL server I managed and it was a really straightforward process: just install (or build) the module from CPAN and done. (Note that this is just an example and you may want to look for more recent versions.)

Installing should be a simple case of either using the OS package manager (if in GNU+Linux), using the cpan utility, or building from source. The OS package manager is recommended because it helps keep things updated automatically.

To verify that it's installed, just try the following command from the terminal (assuming GNU+Linux):

$ perl -e 'use JSON;'

If it doesn't complain, then you should be good to go. If you get errors, then you should get ready to go in an adventure.

History
Why does this post require moderator attention?
You might want to add some details to your flag.

0 comment threads

Sign up to answer this question »