PHP URL/slug accept chars - php

Question

I need to write simple routing system, I have only one question.
When I have url/slug like this
/article/1/simple-article-1
What characters should be allowed there.
Of course letters, digits, '-', '/' and?

Answer 1

.htaccess:
Options -Indexes
RewriteEngine on
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^(.*)$ index.php?/$1 [L,QSA]
PHP:
if(isset($_SERVER['QUERY_STRING'])) {
if(!preg_match('/^[a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*$/', $_SERVER['QUERY_STRING'])) {
return false;
}
$info = explode('/', $_SERVER['QUERY_STRING']);
....
}

Answer 2

What characters should be allowed there.
Usually slugs are all lowercase, with accented characters replaced by letters of the english alphabet and blank characters replaced by a - or an _. Punctuation marks like the period, comma, question mark, exclamation point, apostrophe and quotation mark are generally removed. It may be also truncated to keep a reasonable length.
The reserved chars that may have a particular meaning in the URI are: !, *, ', (, ), ;, :, #, &, =, +, $, /, ?, #, [ and ]. If the character would conflict with a reserved character's purpose, then the conflicting data must be percent-encoded before the URI is formed.
Once you product the URI from its component parts, if you want add characters that are not alpha, digit, -, ., _ or ~ you should always percent-encoding it.
Example:
/article/1/i!want!use!the!exclamation!mark <-- bad
/article/1/i%21want%21use%21the%21exclamation%21mark <-- good