How to identify special character in text string

i have text file and i am reading the text, i need to find what is the special character

Define “special character”, we also don’t know what means a special character.
Can you present some example of what you want?

i am try to find what number is the special character is, in notepad it look like arrow looking up

Load the file into a good text editor, like BBEdit, that will identify character codes for you.

Write a small app that will load the file, then enter each character and its code into a Listbox.

If you have RegExRX, load the file into the text area, then highlight the character. It will tell you its code in the upper, right of the text area.