Last modified: 2024-08-15, 15:20:19
Syntax:
<scheme>:<authority>/<path>?<query>#<fragment>
What happens if you meet a string like:
https://example.com/test/example:1.html?/adam
How can this be parsed? Answer: You don’t
Reserved Characters: - : - / -
? - # - [, ] -
@ - …
If you want to use these characters in the URI (not for parsing reasons above), you need to encode them first.
Percent Encoding must be used for anything that is
not of the following: - Alpha ([a-zA-Z]) - Digit
([0-9]) - - - . - _ -
~
Percent Encoding works by replacing the wanted byte with
%<hexadecimal-representation-of-byte>. Example: We
want to encode ?. 1. Lookup the hexadecimal repr of this
character (e.g. via man ascii or ascii -x) -
$ nix shell nixpkgs#ascii $ ascii -x 00 NUL 10 DLE 20 30 0 40 @ 50 P 60 ` 70 p 01 SOH 11 DC1 21 ! 31 1 41 A 51 Q 61 a 71 q 02 STX 12 DC2 22 " 32 2 42 B 52 R 62 b 72 r 03 ETX 13 DC3 23 # 33 3 43 C 53 S 63 c 73 s 04 EOT 14 DC4 24 $ 34 4 44 D 54 T 64 d 74 t 05 ENQ 15 NAK 25 % 35 5 45 E 55 U 65 e 75 u 06 ACK 16 SYN 26 & 36 6 46 F 56 V 66 f 76 v 07 BEL 17 ETB 27 ' 37 7 47 G 57 W 67 g 77 w 08 BS 18 CAN 28 ( 38 8 48 H 58 X 68 h 78 x 09 HT 19 EM 29 ) 39 9 49 I 59 Y 69 i 79 y 0A LF 1A SUB 2A * 3A : 4A J 5A Z 6A j 7A z 0B VT 1B ESC 2B + 3B ; 4B K 5B [ 6B k 7B { 0C FF 1C FS 2C , 3C < 4C L 5C \ 6C l 7C | 0D CR 1D GS 2D - 3D = 4D M 5D ] 6D m 7D } 0E SO 1E RS 2E . 3E > 4E N 5E ^ 6E n 7E ~ 0F SI 1F US 2F / 3F ? 4F O 5F _ 6F o 7F DEL
As we can see the Hex-Value for ? is 3F. 2.
Therefore, the Percent-Encoded String is now %3F