RSHELL

Program Overview

This project is a simple command shell that reads in user-input commands on one line and work similarly to the bash shell. It is a project for CS100: Software Construction at UC Riverside, taught by Mike Izbicki.

Installation Guide / How to Use

Clone this project at: https://github.com/shawnjzlee/rshell.git.

Once cloned, enter a shell and type cd rshell to enter the project directory.

1. Type make to compile rshell.cpp and ls.cpp and place the executables in the ./bin folder, which will be created by Makefile.

   1. Type make rshell to compile and place rshell in the ./bin folder
   2. Type make ls to compile and place ls in the ./bin folder

2. Running the executable using your existing shell will prompt you with username@hostname$ and wait for an input

3. Press enter after typing in a command, its flags, etc.

   • Typing exit will close the executable.

• Type debug-rshell to enable the -g flag for debugging rshell
• Type debug-ls to enable the -g flag for debugging ls

Bugs/Known Issues/Limitations

###rshell

• ; connector does not work as intended. Even though multiple commands linked together should execute, only the first command before the ; executes.

  [FIX 0.01 (02/02/15)] All connectors are working as intended

• cd produces an error because it is not built into the bash command
• When scripting on Ubuntu 14.04, rshell will not be able to get username. It will instead throw an error and use default guest as its username.
• Multiple && and || connectors does not work as intended because connectors and their logic (as well as precedence) are not implemented correctly; however, single uses of these connectors work as intended.

  [FIX 0.01 (02/02/15)] See FIX 0.01

• exit does not work on a line with multiple commands. exit alone will work; however, ls; exit will not.

  [FIX 0.01 (02/02/15)] See FIX 0.01

• rshell does not work with infinitely large commands
• mkdir test creates a folder as intended; however, mkdir test#folder will treat folder as a comment and create a folder named test.
• touch test creates a file as intended; however, touch test#file will treat file as a comment and create a file named test.

###ls

• -R is incomplete. It acts like -a and can be combined with other flags for similar results (except total number of blocks allocated).
• Unless in a directory with all files of hard links 1, total number of allocated blocks displayed is incorrect.
• ls will not allow directories to be passed in to output its files; however, if files are passed in, it will output those files if they exist.
• ls -a outputs up to 64 characters per line, for better readability in console.
• ls cannot access directories before and after it because it cannot recognize the location.

###io redirection

• >, >> and < work as long as there are spaces on the between arguments.
• | outputs what is passed in through redirection, but does not work with grep and similar commands

###signals and changing directory

• calling a shell within a shell, as well as g++, does not work
• cd,ls, cat, pwd, echo work within rshell