What is , in a URL?

Question

I\'m trying to understand the structure of a URL, and I\'m seeing a lot of %2C. I\'m guessing this is a result of some encoding. What does that stand for?

Answer 1

It's the ASCII keycode in hexadecimal for a comma (,).

You should use your language's URL encoding methods when placing strings in URLs.

You can see a handy list of characters with man ascii. It has this compact diagram available for mapping hexadecimal codes to the character:

   2 3 4 5 6 7       
 -------------      
0:   0 @ P ` p     
1: ! 1 A Q a q     
2: " 2 B R b r     
3: # 3 C S c s     
4: $ 4 D T d t     
5: % 5 E U e u     
6: & 6 F V f v     
7: ' 7 G W g w     
8: ( 8 H X h x     
9: ) 9 I Y i y     
A: * : J Z j z
B: + ; K [ k {
C: , < L \ l |
D: - = M ] m }
E: . > N ^ n ~
F: / ? O _ o DEL

You can also quickly check a character's hexadecimal equivalent with:

$ echo -n , | xxd -p
2c