joeFelek/shell

linux shell project

C shell Implementation

• How it works:

  1. Prints promt with syntax: [cs345sh][user][current_dir]~$

  2. Reads and separates the commands that are between pipes/redirects and stores them in an array of structs. The struct has two fields. An array of strings, that stores each command, and the commands arguments. and a string that stores the pipe/redirection symbol that follows after the command.

     struct Commands {
     	char** argv;
     	char* IO_symbol;
     };
     

  3. For each command, check if there is a pipe or redirection following, change the file descriptors accordingly and then execute.

  4. And loop again to 1. Runs until the exit command.

• Functionalities supported:

  1. Supports all system commands and 3 built-in functions:

     • cd to change directory.
     • exit to terminate the shell.
     • test runs an infinite loop, counter. To test ctrl-s,ctrl-q flow control hotkeys and ctrl-c terminate key.

  2. Pipes and multipipes.

  3. Redirections and combinations with pipes.

  4. Hotkeys ctrl-c terminate, ctrl-h backspase, ctrl-s and ctrl-q flow controls.

In the cs345lib.h there is a short explanation for what each function does.