2021101084

Sriya Venepally

• sirya is a user-defined interactive shell program that can create and manage new processes

To run

• make
• ./a.out
• To exit, type exit

Assumptions

• Maximum input length is 1000 characters.
• Maximum number of commands is 1000.

Features

• Supports multiple commands separated with a semicolon
• Supports commands run with an &, i.e., background processes
• Supports input/output redirection and command pipelines
• ctrl+z pushes any currently running foreground process to the background
• ctrl+c interrupts any currently running foreground process
• ctrl+d logs out of the shell
• autocompletion is supported

Commands

cd

• Switches between directories
• '.' , '..', '-', '~' flags are implemented

pwd

• Prints the absolute path of the current working directory

echo

• Displays the line of text following it

ls

• Lists all the files and directories in the specified directory in alphabetical order
• '-l', '-a' flags are implemented
• Executables are listed in green, files in white and directories in blue

pinfo

• Prints the process related info of the shell
• pinfo <pid> prints the process info of the given pid

discover

• finds the given file from the specified directory
• if no file is given as input, lists all the files and directories in the specified directory
• does not search hidden folders

history

• prints the last 10 command line inputs
• stores only the last 20 commands
• creates a new file hist.txt for implementation

jobs

• prints list of all currently running background processes spawned by the shell, along with job number, process id, and state

sig

• sends a signal to the corresponding process

fg

• brings the running or stopped background job corresponding to job number to the foreground, and changes its state to running.

bg

• changes the state of a stopped background job to running (in the background)