kottans-backend

Git intro.

I first learned about Git. Everything is new for me.

Unix shell

quiz1 quiz2 quiz3 quiz4

I got a ton of info about Linux terminal command, bash scripts.

Git Collaboration

Screenshot

Github issues was new for me, contributing rules is a good idea.

Memory Management

Answers:

1. Segmentation fault.
2. Heap is enlarged to make room for the requested block.
3. Data segment contents static variables initialized in source code, text segment is read-only and contents program code.

5617a111d000-5617a1221000 r-xp 00000000 08:01 15206325                   /bin/bash
5617a1420000-5617a1424000 r--p 00103000 08:01 15206325                   /bin/bash
5617a1424000-5617a142d000 rw-p 00107000 08:01 15206325                   /bin/bash
5617a142d000-5617a1437000 rw-p 00000000 00:00 0 
5617a1dc1000-5617a1f2d000 rw-p 00000000 00:00 0                          [heap]
7f0dcc9d8000-7f0dcc9e3000 r-xp 00000000 08:01 9442157                    /lib/x86_64-linux-gnu/libnss_files-2.27.so
7f0dcc9e3000-7f0dccbe2000 ---p 0000b000 08:01 9442157                    /lib/x86_64-linux-gnu/libnss_files-2.27.so
7f0dccbe2000-7f0dccbe3000 r--p 0000a000 08:01 9442157                    /lib/x86_64-linux-gnu/libnss_files-2.27.so
7f0dccbe3000-7f0dccbe4000 rw-p 0000b000 08:01 9442157                    /lib/x86_64-linux-gnu/libnss_files-2.27.so
7f0dccbe4000-7f0dccbea000 rw-p 00000000 00:00 0 
7f0dccbea000-7f0dccc01000 r-xp 00000000 08:01 9442151                    /lib/x86_64-linux-gnu/libnsl-2.27.so
7f0dccc01000-7f0dcce00000 ---p 00017000 08:01 9442151                    /lib/x86_64-linux-gnu/libnsl-2.27.so
7f0dcce00000-7f0dcce01000 r--p 00016000 08:01 9442151                    /lib/x86_64-linux-gnu/libnsl-2.27.so
7f0dcce01000-7f0dcce02000 rw-p 00017000 08:01 9442151                    /lib/x86_64-linux-gnu/libnsl-2.27.so
7f0dcce02000-7f0dcce04000 rw-p 00000000 00:00 0 
7f0dcce04000-7f0dcce0f000 r-xp 00000000 08:01 9442168                    /lib/x86_64-linux-gnu/libnss_nis-2.27.so
7f0dcce0f000-7f0dcd00e000 ---p 0000b000 08:01 9442168                    /lib/x86_64-linux-gnu/libnss_nis-2.27.so
7f0dcd00e000-7f0dcd00f000 r--p 0000a000 08:01 9442168                    /lib/x86_64-linux-gnu/libnss_nis-2.27.so
7f0dcd00f000-7f0dcd010000 rw-p 0000b000 08:01 9442168                    /lib/x86_64-linux-gnu/libnss_nis-2.27.so
7f0dcd010000-7f0dcd018000 r-xp 00000000 08:01 9442153                    /lib/x86_64-linux-gnu/libnss_compat-2.27.so
7f0dcd018000-7f0dcd218000 ---p 00008000 08:01 9442153                    /lib/x86_64-linux-gnu/libnss_compat-2.27.so
7f0dcd218000-7f0dcd219000 r--p 00008000 08:01 9442153                    /lib/x86_64-linux-gnu/libnss_compat-2.27.so
7f0dcd219000-7f0dcd21a000 rw-p 00009000 08:01 9442153                    /lib/x86_64-linux-gnu/libnss_compat-2.27.so
7f0dcd21a000-7f0dcd671000 r--p 00000000 08:01 13900535                   /usr/lib/locale/locale-archive
7f0dcd671000-7f0dcd858000 r-xp 00000000 08:01 9442067                    /lib/x86_64-linux-gnu/libc-2.27.so
7f0dcd858000-7f0dcda58000 ---p 001e7000 08:01 9442067                    /lib/x86_64-linux-gnu/libc-2.27.so
7f0dcda58000-7f0dcda5c000 r--p 001e7000 08:01 9442067                    /lib/x86_64-linux-gnu/libc-2.27.so
7f0dcda5c000-7f0dcda5e000 rw-p 001eb000 08:01 9442067                    /lib/x86_64-linux-gnu/libc-2.27.so
7f0dcda5e000-7f0dcda62000 rw-p 00000000 00:00 0 
7f0dcda62000-7f0dcda65000 r-xp 00000000 08:01 9442090                    /lib/x86_64-linux-gnu/libdl-2.27.so
7f0dcda65000-7f0dcdc64000 ---p 00003000 08:01 9442090                    /lib/x86_64-linux-gnu/libdl-2.27.so
7f0dcdc64000-7f0dcdc65000 r--p 00002000 08:01 9442090                    /lib/x86_64-linux-gnu/libdl-2.27.so
7f0dcdc65000-7f0dcdc66000 rw-p 00003000 08:01 9442090                    /lib/x86_64-linux-gnu/libdl-2.27.so
7f0dcdc66000-7f0dcdc8b000 r-xp 00000000 08:01 9442225                    /lib/x86_64-linux-gnu/libtinfo.so.5.9
7f0dcdc8b000-7f0dcde8b000 ---p 00025000 08:01 9442225                    /lib/x86_64-linux-gnu/libtinfo.so.5.9
7f0dcde8b000-7f0dcde8f000 r--p 00025000 08:01 9442225                    /lib/x86_64-linux-gnu/libtinfo.so.5.9
7f0dcde8f000-7f0dcde90000 rw-p 00029000 08:01 9442225                    /lib/x86_64-linux-gnu/libtinfo.so.5.9
7f0dcde90000-7f0dcdeb7000 r-xp 00000000 08:01 9442039                    /lib/x86_64-linux-gnu/ld-2.27.so
7f0dce099000-7f0dce09e000 rw-p 00000000 00:00 0 
7f0dce0b0000-7f0dce0b7000 r--s 00000000 08:01 14288493                   /usr/lib/x86_64-linux-gnu/gconv/gconv-modules.cache
7f0dce0b7000-7f0dce0b8000 r--p 00027000 08:01 9442039                    /lib/x86_64-linux-gnu/ld-2.27.so
7f0dce0b8000-7f0dce0b9000 rw-p 00028000 08:01 9442039                    /lib/x86_64-linux-gnu/ld-2.27.so
7f0dce0b9000-7f0dce0ba000 rw-p 00000000 00:00 0 
7ffdddb1e000-7ffdddb3f000 rw-p 00000000 00:00 0                          [stack]
7ffdddb89000-7ffdddb8c000 r--p 00000000 00:00 0                          [vvar]
7ffdddb8c000-7ffdddb8e000 r-xp 00000000 00:00 0                          [vdso]
ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0                  [vsyscall]

Examples: Heap - 5617a1dc1000-5617a1f2d000, Stack - 7ffdddb1e000-7ffdddb3f000, MMS - 7f0dcc9d8000-7f0dcc9e3000

All content is new for me, I'm not sure I understood all of this right.

Python Basics 1

Hackerrank Screenshot

TCP. UDP. Network

Internet 101 Networking for web developers Networking for web developers port-sniffer.py

This task was complicated for me. I found few new modules for python (argparse, socket) and will use it in future.

HTTP & HTTPS

Get list repositories of "Kottans"

curl -i https://api.github.com/users/kottans/repos

Create issue:

curl -i -u dviacheslav -d '{"title":"issue title", "body":"issue body"}' https://api.github.com/repos/dviacheslav/kottans-backend/issues
Enter host password for user 'dviacheslav':************

Answers:

1. Privacy, integrity and identification. If you use HTTP instead HTTPS crime can read your data, change your data, change your destination server.
2. User has private key and public key. Data can be encrypt with private key and decrypt with public key. Also data can be encrypt with public key and decrypt only private key.
3. POST for adding new pet, GET for search pet by name, PUT for all other.

File system

secret.txt file_system_task.py