FAQ 9.10 How do I decode or create those %-encodings on the web?

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9.10: How do I decode or create those %-encodings on the web?

If you are writing a CGI script, you should be using the CGI.pm module
that comes with perl, or some other equivalent module. The CGI module
automatically decodes queries for you, and provides an escape() function
to handle encoding.

The best source of detailed information on URI encoding is RFC 2396.
Basically, the following substitutions do it:

s/([^\w()'*~!.-])/sprintf '%%%02x', ord $1/eg; # encode

s/%([A-Fa-f\d]{2})/chr hex $1/eg; # decode
s/%([[:xdigit:]]{2})/chr hex $1/eg; # same thing

However, you should only apply them to individual URI components, not
the entire URI, otherwise you'll lose information and generally mess
things up. If that didn't explain it, don't worry. Just go read section
2 of the RFC, it's probably the best explanation there is.

RFC 2396 also contains a lot of other useful information, including a
regexp for breaking any arbitrary URI into components (Appendix B).



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Re: FAQ 9.10 How do I decode or create those %-encodings on theweb?

On Mon, 14 Apr 2008 18:03:02 -0700, PerlFAQ Server wrote:

> 9.10: How do I decode or create those %-encodings on the web?
>
> If you are writing a CGI script, you should be using the CGI.pm
> module that comes with perl, or some other equivalent module. The
> CGI module automatically decodes queries for you, and provides an
> escape() function to handle encoding.

This only deals with CGI scripts, but one might need to create a URI
encoding even when one is not writing a CGI script. Perhaps this FAQ
should mention the URI::Escape module too.

Re: FAQ 9.10 How do I decode or create those %-encodings on the web?

In article , Ben Bullock
wrote:

> On Mon, 14 Apr 2008 18:03:02 -0700, PerlFAQ Server wrote:
>
> > 9.10: How do I decode or create those %-encodings on the web?
> >
> > If you are writing a CGI script, you should be using the CGI.pm
> > module that comes with perl, or some other equivalent module. The
> > CGI module automatically decodes queries for you, and provides an
> > escape() function to handle encoding.
>
> This only deals with CGI scripts, but one might need to create a URI
> encoding even when one is not writing a CGI script. Perhaps this FAQ
> should mention the URI::Escape module too.

Good idea. I'll add that to my to do list.

Thanks, :)