UNIX Shell Clone

A UNIX-style shell project built in C with both a local shell and a TCP-based remote shell. The codebase also includes a scheduler-driven execution path for long-running demo programs, live state logging, and a standalone scheduler test harness.

Features

• Local shell executable: myshell
• Remote shell server and client: server and client
• Task scheduling support for program execution
• Preemption and re-queueing for long-running tasks
• Live demo progress updates for ./demo N
• Colored task-state output in the server logs
• Gantt-style execution summary for preempted workloads
• Standalone scheduler test binary: scheduler_test

Project Layout

• src/main.c — entry point for the local shell
• src/client.c — remote shell client
• src/server.c — remote shell server and task execution logic
• src/scheduler.c — task scheduling core
• src/scheduler_test.c — scheduler test harness
• src/demo.c — long-running demo program
• include/ — project headers

Build

Build everything with:

make clean && make all

This produces:

• myshell
• client
• server
• scheduler_test
• demo

Run

Local Shell

Start the local shell:

./myshell

Remote Shell

Start the server in one terminal:

./server

Start the client in another terminal (multiple clients can be started in multiple terminals):

./client

Example commands inside the client:

pwd
ls -l
./demo 3
exit

Demo Program

./demo N runs for N one-second iterations and is used to show scheduling behavior and real-time progress updates.

Example:

./demo 5

Scheduler Test

The standalone scheduler test can be run with:

./scheduler_test

It exercises the task queue, dispatch logic, preemption, and re-queueing behavior without needing the full client/server flow.

Notes

• The server prints colored task-state logs for easier reading.
• The execution summary includes a Gantt-style timeline when preemption occurs.
• Output files such as output.txt and error.log may be created depending on the commands you run.
• Use exit in the client to close the remote session cleanly.

Requirements

• A C compiler
• POSIX-compatible environment
• Standard build tools such as make

License

No explicit license has been provided.