hexdumper task

TODO.md

@@ -1,10 +0,0 @@
-# Things that tasks would be cool
-
-## Kryptography
-- [ ] Caesar-encryption, decryption, brute force
-
-## Math
-- [ ] calculate determinant of a matrix
-
-## General Tech
-- [ ] Regex

TODO.norg

@@ -0,0 +1,15 @@
+This is a list of tasks that would be cool to add.
+
+* Tasks
+** Basic
+*** Files
+		- ( ) Hex dumper
+*** Networking
+		- ( ) Mini curl
+*** Packaging
+		- ( ) Installing a package to your system
+		- ( ) Building a library
+
+** Cryptography
+*** Signature
+		- ( ) Check a signature with OpenSSL

Tasks.md

@@ -178,7 +178,7 @@ Difficulty: 2/5
     - How many possible strings consisting of 16 alphanumeric characters can exist?
     - Add the possibility for a second argument `-v` that indicates your script should be more
       verbose.
-    - print the security bits ($log_2(L)$ where $L$ is the total number of possibilites) when the 
+    - print the security bits ($log_2(L)$ where $L$ is the total number of possibilities) when the
       `-v` flag is applied
 
 Example:
@@ -287,3 +287,78 @@ A regex that fullfills the requirements is `\b[a-z][AEIOUaeiou]([a-w]|[A-W])`.
 [Code Example](src/tasks/regex.py)
 
 </details>
+
+## Making a Hexeditor
+
+In this section, we're building a little hexeditor. You will be able to install
+it on your system and use it instead of the `hexdump` and `xxd` built into most 
+Linux distributions.
+
+Hexdumping is actually really simple, all you have to do is read a file and
+print it's direct content interpreted as numbers in hexadecimal. Apply some
+fancy string formatting and we're done!
+
+The editing part is a lot harder. It requires us to build a functioning TUI -
+Terminal User Interface, as working with command line arguments or regular
+reading from stdin won't help us much for editing a file. (if that's your thing,
+use `ed`.).
+
+Note: If you're looking for a great, fully featured hexeditor, I'd recommend
+`bvi` ("binary vi"), which is packaged by most distributions.
+
+-> `apt-get install bvi`
+
+Note: I have no Idea how to install a python script as executable on windows, I
+don't like windows either, so no support for installing stuff on windows.
+
+### A. Hexdumper
+Difficulty: 2/5
+
+
+1. Dump the data of [data/metasyntactic.md](./data/metasyntactic.md) -- In
+   Hexadecumal.
+2. Make the dumped Bytes look pretty, something like the example below:
+
+<details>
+    <summary>Hexdump Example Display</summary>
+
+`data/metasyntactic.md` looks like this when hexdumped:
+
+```text
+Line      Data
+=================================================
+0000000 ┃ 6f4e 6574 203a 6854 7369 6920 2073 6874
+0000010 ┃ 2065 6957 696b 6570 6964 2061 6170 6567
+0000020 ┃ 6620 726f 6d20 7465 7361 6e79 6174 7463
+0000030 ┃ 6369 7620 7261 6169 6c62 7365 6920 206e
+0000040 ┃ 6e45 6c67 7369 2c68 3220 3230 2d33 3930
+0000050 ┃ 302d 2e35 4620 6e69 2064 6874 0a65 7075
+0000060 ┃ 7420 206f 6164 6574 6f20 6972 6967 616e
+0000070 ┃ 206c 685b 7265 5d65 6828 7474 7370 2f3a
+0000080 ┃ 652f 2e6e 6977 696b 6570 6964 2e61 726f
+0000090 ┃ 2f67 6977 696b 4d2f 7465 7361 6e79 6174
+00000a0 ┃ 7463 6369 765f 7261 6169 6c62 2965 0a2e
+00000b0 ┃ 230a 4d20 7465 7361 6e79 6174 7463 6369
+00000c0 ┃ 7620 7261 6169 6c62 0a65 230a 2023 6f54
+00000d0 ┃ 6c6f 0a73 460a 6f72 206d 6957 696b 6570
+00000e0 ┃ 6964 2c61 7420 6568 6620 6572 2065 6e65
+00000f0 ┃ 7963 6c63 706f 6465 6169 540a 6968 2073
+0000100 ┃ 7261 6974 6c63 2065 7369 6120 6f62 7475
+0000110 ┃ 6d20 7465 7361 6e79 6174 7463 6369 7620
+...
+```
+
+<details>
+<summary>Hints</summary>
+
+TODO: add hints
+
+</details>
+<details>
+<summary>Solution</summary>
+
+TODO: formulate solution text
+
+[Code Example](src/tasks/hexdumper-a.py)
+
+</details>

src/tasks/hexdumper-a.py

@@ -0,0 +1,8 @@
+#!/usr/bin/env python3
+import sys
+
+def main():
+    # parse args
+
+if __name__ == "__main__":
+    main()