C - Simple Shell.
Project to be done in teams of 2 people (your team: Anthony Ngunjiri, Siele Kipkurui).
Background Context:
Write a simple UNIX command interpreter.
Resources Read or watch:
Unix shell
Thompson shell
Ken Thompson
Everything you need to know to start coding your own shell concept page.
General:
Who designed and implemented the original Unix operating system
Who wrote the first version of the UNIX shell
Who invented the B programming language (the direct predecessor to the C programming language)
Who is Ken Thompson
How does a shell work
What is a pid and a ppid
How to manipulate the environment of the current process
What is the difference between a function and a system call
How to create processes
What are the three prototypes of main
How does the shell use the PATH to find the programs
How to execute another program with the execve system call
How to suspend the execution of a process until one of its children terminates
What is EOF / “end-of-file”?
Requirements:
Allowed editors: vi, vim, emacs.
All files will be compiled on Ubuntu 20.04 LTS using gcc, using the options -Wall -Werror -Wextra -pedantic -std=gnu89
All files should end with a new line
A README.md file, at the root of the folder of the project is mandatory
Code should use the Betty style. It will be checked using betty-style.pl and betty-doc.pl
Your shell should not have any memory leaks
No more than 5 functions per file
All header files should be include guarded
Use system calls only when you need to (why?)
Write a README with the description of your project
You should have an AUTHORS file at the root of your repository, listing all individuals having contributed content to the repository. Format, see Docker.
There should be one project repository per group.
Output:
Unless specified otherwise, your program must have the exact same output as sh (/bin/sh) as well as the exact same error output.
The only difference is when you print an error, the name of the program must be equivalent to your argv[0]
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)
Compilation:
Your shell will be compiled this way: gcc -Wall -Werror -Wextra -pedantic -std=gnu89 *.c -o hsh