rshell

rshell imitates the functionality of a bash terminal. rshell performs the following steps:

Assignment 1

1. Prints the command prompt with the user's username<userName>@<hostName> $
2. Read in a command(s) on one line. Commands can be separated by connectors.
   • Arguements are separated by spaces.
   • Connectors include ;, &&, ||, and #.
   • Able to mix and match connectors and commands and still logically work.
3. Execute the line of commands
   • If a command is followed by ;, then the next command is always executed.
   • If a command is followed by &&, then the next command is executed only if the first one succeeds.
   • If a command is followed by ||, then the next command is executed only if the first one does not succeed.
   • Anything found after the first found # is considered a comment will not be passed through the terminal.

Assignment 2

1. Allows the user to utilize the 'test' command to see if a directory exists or not.
   • The 'test' command could be tested in 2 ways: test -flag test/file/path OR [ -flag test/file/path ].
   • The user is allowed to use one of three flags: -e, -f, -d.
   • The -e flag will be used by default if none are defined.
   • If a directory exists the terminal will output (True).
   • If a directory is not found/doesn't exist, the ternimal will output (False).
2. The user may use precedence parameters ( ) These parameters are used to change the precedence of returns of commands, connectors, and chains of connectors.
   • Ex) echo A && echo B || echo C && echo D will output:
   • A
   • B
   • D
   • However, the parenthesis may change the precedence of these commands.
   • Ex) (echo A && echo B) || (echo C && echo D) will output:
   • A
   • B

Bugs(Assignment 1)

1. cd: This alone other built-in bash commands will not work due to the fact that they have no executable file in the bin
2. exit: Sometimes requires to be input 2-4 times. Functionality works, just this bug was observed enough times
3. &&: Sometimes when and || is based in the sequence false || true && , and && after this do not get run.
4. echo: when doing echo "[connectot]" nothing is output, echo " [anything else]" works as expected
5. Massive sequences of || (5>) with all except last returning false will return the last || as false in cases
6. Error comes up on first input in the command line. Works fine after that

Bugs (Assignment 2)

1. cd: This alone other built-in bash commands will not work due to the fact that they have no executable file in the bin
2. echo: when doing echo "[connectot]" nothing is output, echo " [anything else]" works as expected
3. Seg fault may occur if # is put in multiple ().
4. &&: Sometimes when and || is based in the sequence false || true && , and && after this do not get run.
5. Multi exit VERY unlikely

How To Run rshell

$ git clone https://github.com/samhwangg/rshell.git
$ cd rshell
$ git checkout hw2
$ make
$ bin/rshell