██     ██  █████  ██      █████  █████▄
   ▓███▄ ▄███▒██▓  ██▓██▓   ▒██▓  ██▒██▓  █▌
   ▓██▀███▀██░██▒  ██▒██▒   ▒██▒  ██░██▒  █▌
   ▒██  ▀ ▒██░██   ██▒██░   ░██   ██░██   █▌
   ▒██▒   ░██░▒███▀█▄░██████░▒███▀█▄░█████▓
   ░  ░      ░░ ▒░  ░░ ░ ▒  ░░ ▒░  ░ ░ ▒  ▒
          ░      ░   ░   ░  ░   ░      ░
  File transfer over TCP/IP on sockets (POSIX)
=================================================
  ___   _      ___   _      ___   _      ___   _
 [(_)] |=|    [(_)] |=|    [(_)] |=|    [(_)] |=|
  '-`  |_|     '-`  |_|     '-`  |_|     '-`  |_|
 /mmm/  /     /mmm/  /     /mmm/  /     /mmm/  /
       |____________|____________|____________|
        mqlqd clients          |
  send files to the server     |
                               \         _______
             .-------.          \_______| _____ |
             | -----.-----.      server ||_____||
             | -----| -----\    running ||_____||
             | -----| ----- |     mqlqd ||_____||
             | -----| ----- |    daemon ||_____||
             '------| ----- |           ||_____||
                    '-------'           ||_____||
    listens for incoming connections    ||_____||
  receives and saves files in a storage |       |
     directory unique to the client     |=======|


CLIENT USAGE
============
Transfer file(s) over TCP/IP to the server running the mqlqd_daemon.
Usage:
  mqlqd_client [OPTIONS] [file paths as trailing arguments ...]

  -a, --addr arg  Server IP address with the mqlqd_daemon.
                  (default: 127.0.0.1)
  -p, --port arg  Port number of the daemon on the server.
                  (default: 42069)
  -c, --cat       Print file content (cat like utility mode).
  -f, --file arg  File path of the file to transmit.
  -h, --help      Show usage help.
  -u, --urge 1-7  Log urgency level. (All messages </> Only critical)


DAEMON USAGE
============
Accept file(s) over TCP/IP from the clients running the mqlqd_client.
Usage:
  mqlqd_daemon [OPTION...]

  -d, --dir  arg  Path to the storage dir, else default storage under cwd.
                  (default: ./mqlqd_storage)
  -p, --port arg  Use port number as identity of the daemon on the server.
                  (default: 42069)
  -h, --help      Show usage help.
  -u, --urge 1-7  Log urgency level. (All messages </> Only critical)


BUILD
=====
To make clean build
$ ./scripts/build.sh clean

To make cleaner build (for edge cases)
$ ./scripts/build.sh cleaner

Ninja (build system) is optional: change Generator -G Ninja in the above build script.


REQUIREMENTS
============
Platform requirement: Linux, BSD or origin from the UNIX family (POSIX compliant os).
* libc    To work with the socket API (socket API support is mandatory for the platform)

3rd party dependencies (fetched automatically with CMake fetch content)
* fmtlib  (https://github.com/fmtlib/fmt)
* cxxopts (https://github.com/jarro2783/cxxopts)

Tests require:
* gtest   (https://github.com/google/googletest)


RELATED ARTICLES
================
Linux man-pages are crucial for understanding of the sockets API.

The Linux socket API explained (brilliant simple and concise introduction)
https://www.youtube.com/watch?v=XXfdzwEsxFk

A brief intro to TCP/IP and a basic client-server setup in C++ that uses TCP/IP
https://lenngro.github.io/how-to/2021/01/05/Simple-TCPIP-Server-Cpp/

Berkeley BSD and POSIX sockets API (history)
https://en.wikipedia.org/wiki/Berkeley_sockets

OSI model (Open Systems Interconnection model) (history)
https://en.wikipedia.org/wiki/OSI_model


LICENSE
=======
0BSD