MKS65C-shell

Raunak Chowdhury and Tina Wong

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TODO:

• Read a line at a time, parse the line to separate the command from its arguments. It should then fork and exec the command.
• Read and separate multiple commands on one line with ;
• Can change dirs and exit the shell
• Implement simple redirection using > (redirecting stdout) and < (redirecting stdin)
• Implement simple pipes

Features

• Unlimited command chains using semicolons, regardless of spacing
• shell command prompt
• cd
• exit
• redirecting into a file (> and >>)
• redirecting stdin (<)
• Can chain pipes

Attempted Features

Bugs

• If you make a typo (such as cd.. instead of cd ..), exit won't work on the next line.

Function Headers

shell.c

• handles all line parsing and executing command functions
• char * strip( char * string)
  • Inputs: char * string
  • Returns a char array that has been stripped of leading/trailing whitespace.
  • Strips leading and trailing whitespace.
• char ** parse_args( char * line, char * delimiter )
  • Inputs: char * line, char * delimiter
  • Returns an array derived from the line using strsep.
  • Processes the line, including pipes and redirects. Ignores whitespace.
• void redirect_stdout(char ** arr, int index)
  • Inputs: char ** arr, int index
  • Does not return
  • Takes in the command and executes redirection of that command into a text file.
• void redirect_stdin(char ** arr, int index)
  • Inputs: char ** arr, int index
  • Does not return
  • Takes in the command and redirects text file in to stdin.
• void piping(char ** arr, int index)
  • Inputs: char ** arr, int index
  • Does not return
  • Takes in the command and executes piping.

prompt.c

• handles shell display
• char * get_hostname()
  • No input
  • Returns a char pointer to the user's hostname
  • Gets and returns hostname of user.