Developed from scratch for CSE assignment
make
./Pshell
All builtins are intended to work just as you may expect
ls, ll, la, cd, history, echo, pwd, clear, pinfo, setenv, unsetenv, jobs, kjob, fg, bg, overkill, quit, cronjob, nightswatch
Futher details on functionality can be read from assignment descriptions.
- Input-output redirection with
|,>,<,>>is supported - commands like rm, man (or any non-builtins) can be executed as external processes
- appending
&at the final position will run the exerternal process as a backgound process - Each ;-separated command is executed separately
- most builtins verify whether correct number of arguments and flags are provided
- ls (ll, la) allows multiple arguments, and accordingly lists content of all the directories provided
- CTRL-Z will stop a foreground process and push it to backgound
- CTRL-C will only kill the a foreground process (if exists)
- multiple up-arrows (
^[[A) can be used to execute a previously executed command.
- shell.c contains the main funtion with initializer like defining ~, user etc.
- It uses takingInput.c to take_input and calls the parse_and_execute from redirection.c
- redirection.c breaks the commands separated by pipe & checks for input-output redirection to accordingly set the stdin and stdout of each command
- It then uses parseInput function to break down command into flags, arguments etc
- driver.c checks if the command is one of the builtins
- The builtins.c, jobs.c, history.c, ls.c, nightswatch.c (which also maintains linked list to track bg processes) define the various builtin functions
- If the command isn't a builtin, the shell.c checks for '&' and accordingly runs the command as background / foreground
- externalProcessess.c defines how to run the external processes, with interrupt handler to mark background process end
- The tilde.c provides basic functions to convert between ~ and absolute value in a path (~ is set to the executation path of Pshell)
- makefile compiles everything & produces the executable: Pshell