How to implement the pseudo-static of the PHP classification directory

How to implement the pseudo-static of the PHP classification directory
Want to implement similar to WordPress, such as the classification of the connection address is http://www.xxx.com/catname/

Because the category ID does not appear in the URL, but the category name, how do I read the article under that category? How to write pseudo-static rules
------to solve the idea----------------------
Pseudo-Static only one/category/(. *),/category?catename=$1
The principle is the same as the ID, but one is to use numbers to check, one is to use a string to check

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