What is the proper way of denoting URI with diacritics (letters with accents)? - perl

Question

What is the correct and official way of using diacritics in URI?
I have 3 different ways shown below:
Here á = %E1, â = %E2, space = %20, comma = %2C, but this link doesn't work properly since the characters are mangled:
http://www.recordspreservation.org/cgi-bin/list_directory_1.cgi?directory=%2CBrasil%2CGoi%E1s%2CLuzi%E2nia%2CSanta%20Luzia%2CBatismos%201749-1753%2CImagens&image_name=_MG_5229.JPG
Here space = %20, comma = %2C and I don't do anything with the a's. This link works:
http://www.recordspreservation.org/cgi-bin/list_directory_1.cgi?directory=%2CBrasil%2CGoiás%2CLuziânia%2CSanta%20Luzia%2CBatismos%201749-1753%2CImagens&image_name=_MG_5229.JPG
Here space = +, comma = %2C and I don't do anything with the a's. This link works:
http://www.recordspreservation.org/cgi-bin/list_directory_1.cgi?directory=%2CBrasil%2CGoiás%2CLuziânia%2CSanta+Luzia%2CBatismos+1749-1753%2CImagens&image_name=_MG_5229.JPG

Answer 1

The characters in a URL string must be within in a restricted subset of 7-bit ASCII, and no encoding is specified for wide characters
Some of that set are unreserved, and may be used literally anywhere the syntax allows
The remaining characters are reserved because they form part of the URL syntax; reserved characters must be percent-encoded if they are used outside their syntactical meaning
Eight-bit characters that are in neither the reserved nor the unreserved categories must always be percent-encoded
##Unreserved characters
0 to 9
A to Z
a to z
-
.
_
~
##Reserved characters
! - %21
# - %23
$ - %24
& - %26
' - %27
( - %28
) - %29
* - %2A
+ - %2B
, - %2C
/ - %2F
: - %3A
; - %3B
= - %3D
? - %3F
# - %40
[ - %5B
] - %5D
This link doesn't work properly since the characters are mangled
That is a problem between the client and the server. It looks like you're sending ISO-8859-1 characters, in which scheme E1 and E2 correspond to e acute, and e circumflex. But if your server is expecting UTF-8 encoding then those should appear as byte sequences C3 A1 and C3 A2
I can't tell what encoding is expected by your server, but it clearly isn't what you're sending. The current standard is to encode non-ASCII characters in UTF-8 and percent-encode the resulting bytes
###Update
The best solution is to use the URI module, which will encode character string as necessary
Take special note that, if you need to use UTF-8-encoded characters in your source code, as below, then you must have use utf8 at the top of your program. You also need to make sure that your editor is writing UTF-8 data to the program file.
use utf8;
use strict;
use warnings 'all';
use feature 'say';
use URI;
my $url = URI->new('http://www.recordspreservation.org/cgi-bin/list_directory_1.cgi?directory=,Brasil,Goiás,Luziânia,Santa Luzia,Batismos 1749-1753,Imagens&image_name=_MG_5229.JPG');
say $url;
###output
http://www.recordspreservation.org/cgi-bin/list_directory_1.cgi?directory=,Brasil,Goi%C3%A1s,Luzi%C3%A2nia,Santa%20Luzia,Batismos%201749-1753,Imagens&image_name=_MG_5229.JPG