Basic shell.
- help
- pwd
- cd
- program execution
- path resolution
- I/O redirection (There is the comment in the code about pipes, so turned out that pipes are being created in other way than I thought, but the comment is still right)
- Signal handling (very limited)
- We can't kill processes
- Processes that works in the background still running even after work of the shell is done
- We can't resume execution of paused processes (can't send signal CONT)
- Impossible freely toggle processes between running in the foreground and in the background
- So basically we can't perfrom any operations that require any sort of keeping information about processes