A custom-made version of Netcat

Ex2 in Operating Systems @ Ariel University

Overview

Developed a custom-made version of Netcat that uses sockets to:

• Show output/input of executed program, in another terminal (using sockets and pipes)
• Chat between terminals (using sockets and pipes)

Netcat is a versatile networking tool used for interacting with network sockets. For more information on using netcat, refer to the man nc command.

We also developed a dummy Tic-Tac-Toe AI and used it to test our work.

MyNetcat - (90 Points)

Folders: q2, q6

Implement mync to redirect input/output of a specified program. Supporting the following connections:

• TCP
• UDP
• Unix Domain Sockets (UDS)

Usage

The final code can be found under the q6 folder.

If you intend to use the Tic-Tac-Toe program from q1 please make sure to compile it (you can run make in the main directory to compile all questions).

./mync
      Optional:
      -e <program arguments>: run a program with arguments
      -i <parameter>: take input from opened parameter
      -o <parameter>: send output to opened parameter
      -b <parameter>: send output and input to opened parameter
      -t <timeout>: set timeout for UDP connection. defaults to 0

      Parameters:
      TCPS<PORT>: open a TCP server on port PORT
      TCPC<IP,PORT> / TCPC<hostname,port>: open a TCP client and connect to IP on port PORT
      UDPS<PORT>: open a UDP server on port PORT
      UDPC<IP,PORT> / UDPC<hostname,port>: open a UDP client and connect to IP on port PORT
      UDSSD<path>: open a Unix Domain Sockets Datagram server on path\n"
      UDSCD<path>: open a Unix Domain Sockets Datagram client and connect to path
      UDSSS<path>: open a Unix Domain Sockets Stream server on path
      UDSCS<path>: open a Unix Domain Sockets Stream client and connect to path

Examples

A video of all possible examples and combinations can be found here (CLICK HERE)

1. Starts a TCP server on port 4050 for input; output goes to stdout.

mync -e "ttt 123456789" -i TCPS4050

2. Starts a TCP server on port 4050 for both input and output.

mync -e "ttt 123456789" -b TCPS4050

3. TCP server on port 4050 for input, output sent to TCP client at localhost:4455.

mync -e "ttt 123456789" -i TCPS4050 -o TCPClocalhost,4455

4. UDP server on port 4050 with a 10-second timeout.

mync -e "ttt 123456789" -i UDPS4050 -t 10

5. UDP server on port 4050, echoing messages back to the sender, with a 12-second timeout.

mync -e "ttt 123456789" -b UDPS4050 -t 12

Tic-Tac-Toe AI (10 Points)

Folder: q1

The program receives a 9-digit strategy number as a parameter (e.g., 198345762), which must include each digit from 1 to 9 exactly once. If the input is invalid (missing/duplicate digits, includes 0, incorrect length), print Error\n and exit.

Dummy AI Strategy

• MSD/LSD: Most/Least Significant Digit
• The program prioritizes moves based on digit significance.
• Always choose the highest priority slot available.
• If only one slot remains, choose the LSD slot.

Gameplay

1. Program plays first by choosing the highest priority slot and prints the move.
2. The human player responds with a move (1-9).
3. The game continues until a win, loss, or draw.