SIMPLE SHELL PROJECT

0x16. project is a simple UNIX command interpreter done by Solomon Musyoki and Cynthia Odoyo

The Shell Should:

1. Display a prompt and wait for the user to type a command. A command line always ends with a new line.
2. Handle command lines with arguments.
3. Handle the PATH.
4. Implement the exit built-in, that exits the shell.
5. Implement the env built-in, that prints the current environment.
6. Write your own getline function.
7. Handle arguments for the built-in exit.
8. Implement the setenv and unsetenv builtin commands.
9. Implement the builtin command cd:
10. Handle the commands separator ;
11. Handle the && and || shell logical operators.
12. Implement the alias builtin command.
13. Handle variables replacement /$? variable and /$$ variable.
14. Handle comments (#).
15. The shell can take a file as a command line argument.

Functions and system calls

List of allowed functions and system calls

• access (man 2 access)
• chdir (man 2 chdir)
• close (man 2 close)
• closedir (man 3 closedir)
• execve (man 2 execve)
• exit (man 3 exit)
• _exit (man 2 _exit)
• fflush (man 3 fflush)
• fork (man 2 fork)
• free (man 3 free)
• getcwd (man 3 getcwd)
• getline (man 3 getline)
• getpid (man 2 getpid)
• isatty (man 3 isatty)
• kill (man 2 kill)
• malloc (man 3 malloc)
• open (man 2 open)
• opendir (man 3 opendir)
• perror (man 3 perror)
• read (man 2 read)
• readdir (man 3 readdir)
• signal (man 2 signal)
• stat (__xstat) (man 2 stat)
• lstat (__lxstat) (man 2 lstat)
• fstat (__fxstat) (man 2 fstat)
• strtok (man 3 strtok)
• wait (man 2 wait)
• waitpid (man 2 waitpid)
• wait3 (man 2 wait3)
• wait4 (man 2 wait4)
• write (man 2 write)