Welcome to WyShell

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Getting Started

To run WyShell, you have two convenient options:

Option 1: Manual Compilation and Run

1. Clone the Repository:

   git clone https://github.com/sambuaneesh/wyShell
   cd wyshell

2. Compile the Shell: Compile the WyShell binary using the following command:

   make main

3. Run WyShell: Run WyShell by executing the compiled binary:

   ./wysh

Option 2: One-Step Compilation and Run

You can compile and run WyShell in a single command:

make run

Cleaning Up

To clean up the compiled files and binaries, you can use the following command:

make clean

This command will remove the WyShell executable, the pastevents.txt file, and any other compiled binaries, ensuring a tidy project structure.

Table of Contents

• Welcome to WyShell
  • Getting Started
    • Option 1: Manual Compilation and Run
    • Option 2: One-Step Compilation and Run
  • Cleaning Up
  • Table of Contents
  • Basic System Calls
    • Display Requirement
    • Input Requirements
  • Shell Commands
    • warp [path]
    • peek [flags] [path/name]
    • pastevents
    • System Commands
      • Foreground Process
      • Background Process
      • ping <pid> <signal_number>
      • Ctrl - C, Ctrl - D, Ctrl - Z
    • proclore [pid]
    • seek [flags] [search] [target_directory]
  • Processes, Files, and Miscellaneous
    • I/O Redirection
    • Pipes
    • Redirection along with Pipes
    • Process Management
    • Neonate Command
  • Networking
    • iMan [command_name]

Basic System Calls

Display Requirement

The shell prompt is displayed in the following format:

<Username@SystemName:~>

• <Username>: Current username
• @: Separator
• SystemName: System's name
• ~: Represents the current home directory

Example:

<JohnDoe@SYS:~>

Input Requirements

• The shell supports ; or & separated lists of commands.
• Commands can be separated by random spaces and tabs.
• ; is used for sequential commands.
• & runs the preceding command in the background.

Example:

<JohnDoe@SYS:~> command1 ; command2 & command3

Shell Commands

warp [path]

The warp command changes the current directory to the specified path and updates the prompt accordingly. It supports symbols like . (current directory), .. (parent directory), ~ (home directory), and - (previous directory).

Example:

<JohnDoe@SYS:~> warp test
/home/johndoe/test
<JohnDoe@SYS:~/test> warp ~
/home/johndoe
<JohnDoe@SYS:~>

peek [flags] [path/name]

The peek command lists files and directories in the specified directory. It supports -a (show hidden files) and -l (display extra information) flags.

Example:

<JohnDoe@SYS:~> peek test
# Output
<JohnDoe@SYS:~> peek -al test
# Output with extra information

pastevents

The pastevents command displays the 15 most recent command statements based on certain constraints. It is persistent across different shell runs.

Example:

<JohnDoe@SYS:~> pastevents
# Output the 15 most recent commands
<JohnDoe@SYS:~> pastevents execute 1
# Execute the command at position 1
<JohnDoe@SYS:~> pastevents purge
# Clear all pastevents

System Commands

Foreground Process

Foreground processes wait for completion, and their output is displayed in the terminal.

Example:

<JohnDoe@SYS:~> sleep 5
# Executes sleep command in foreground

Background Process

Background processes run asynchronously. Their PIDs are displayed in the terminal.

Example:

<JohnDoe@SYS:~> sleep 10 &
# Executes sleep command in the background

ping <pid> <signal_number>

The ping command is used to send signals to processes. Take the pid of a process and send a signal to it corresponding to the provided signal number. Print error “No such process found” if the process with the given pid does not exist.

Example:

<JohnDoe@SYS:~> ping 221 9
Sent signal 9 to process with pid 221
<JohnDoe@SYS:~> ping 430 41
Sent signal 9 to process with pid 430

Ctrl - C, Ctrl - D, Ctrl - Z

• Ctrl - C: Interrupts any currently running foreground process by sending it the SIGINT signal. It has no effect if no foreground process is currently running.
• Ctrl - D: Logs out of your shell (after killing all processes) while having no effect on the actual terminal.
• Ctrl - Z: Pushes the (if any) running foreground process to the background and changes its state from “Running” to “Stopped”. It has no effect on the shell if no foreground process is running.

proclore [pid]

The proclore command provides information about a process with the given PID.

Example:

<JohnDoe@SYS:~> proclore
# Displays information about the shell

 process
<JohnDoe@SYS:~> proclore 301
# Displays information about the process with PID 301

seek [flags] [search] [target_directory]

The seek command searches for a file/directory in the specified target directory. It supports -d (look for directories only) and -f (look for files only) flags.

Example:

<JohnDoe@SYS:~> seek newfolder ./doe
# Output matching files/directories in ./doe

Processes, Files, and Miscellaneous

I/O Redirection

The shell supports input/output redirection using >, >>, and < operators.

Example:

<JohnDoe@SYS:~> echo "Hello world" > newfile.txt
# Redirects output to newfile.txt
<JohnDoe@SYS:~> wc < a.txt
# Reads input from a.txt and performs word count

Pipes

The shell supports piping multiple commands.

Example:

<JohnDoe@SYS:~> echo "Lorem Ipsum" | wc
# Pipes output of echo to wc command

Redirection along with Pipes

The shell supports redirection along with pipes.

Example:

<JohnDoe@SYS:~> cat < a.txt | wc | sed 's/ //g' | cat > b.txt
# Redirects input from a.txt, pipes through wc and sed, and outputs to b.txt

Process Management

The shell supports process management commands fg and bg.

Example:

<JohnDoe@SYS:~> fg 620
# Brings process with PID 620 to foreground
<JohnDoe@SYS:~> bg 620
# Changes process with PID 620 to background

Neonate Command

The neonate command prints the Process-ID of the most recently created process at specified intervals until the 'x' key is pressed.

Example:

<JohnDoe@SYS:

~> neonate -n 4
# Prints PID every 4 seconds until 'x' is pressed
11810
11811
11811
11812
11813 # Key 'x' is pressed, terminating the printing

Networking

iMan [command_name]

The iMan command fetches man pages from http://man.he.net/ using sockets.

Example:

<JohnDoe@SYS:~> iMan sleep
# Fetches and displays the man page for the 'sleep' command

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