README.md

Operating Systems and Networks Assignment 2,3 - C Shell

Sriteja Reddy Pashya | 2021111019

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FML Shell

Requirements

• GCC compiler
• Linux OS (preferably Ubuntu)

Running Shell

From the root directory of project, run make followed by ./fmlsh

File & Functions

• main.c

  • Run Shell Loop
  • Executes respective function based on arguments from command

• command.c

  • Takes input from user
  • Separates input into commands separated by ; and &, and arguments separated by whitespace

• prompt.c

  • Print prompts

• cd.c

  • Navigates to a given directory

• pwd.c

  • Prints the working directory

• echo.c

  • Prints user input after removing excess whitespace

• discover.c

  • executes the discover command,
  • Assumes that all file names are enclosed in ""

• history.c

  • Prints history of commands stored in .fmlsh_history
  • Doesn't store consecutive commands with the same arguments when extra whitespace is removed

• .fmlsh_history

  • stores all the commands

• ls.c

  • Executes the ls command

• pinfo.c

  • Executes the pinfo command

• runner.c

  • Executes the processes by forking into a child process

• headers.h

  • Contains all necessary headers

Other Implementations

• exit to exit the shell.
• fml easter egg.

Assumptions

• Reasonable assumptions are made for things like length of current path, number of commands, command length, etc. The shell will work perfectly for all "day to day work".

• echo will treat everything as normal character.

• File and directory names shouldn't contain spaces or special characters.

• Any error while running a command will result in aborting the command after printing an error message.

• I/O redirection operators <, >, >> and pipes | must have whitespace before and after them.