By Spencer Cheng, featuring Julien Barbier Project to be done in teams of 2 people (your team: Godswill Kalu, Vatalis Ibeh)

At the end of this project, you are expected to be able to explain to anyone, without the help of Google:

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”?

Allowed editors: vi, vim, emacs All your files will be compiled on Ubuntu 20.04 LTS using gcc, using the options -Wall -Werror -Wextra -pedantic -std=gnu89 All your files should end with a new line A README.md file, at the root of the folder of the project is mandatory Your 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 your header files should be include guarded Use system calls only when you need to (why?)

*There should be one project repository per group. If you and your partner have a repository with the same name in both your accounts, you risk a 0% score. Add your partner as a collaborator. *

More Info 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] (See below) Example of error with sh:

$ echo "qwerty" | /bin/sh /bin/sh: 1: qwerty: not found $ echo "qwerty" | /bin/../bin/sh /bin/../bin/sh: 1: qwerty: not found $ Same error with your program hsh:

$ echo "qwerty" | ./hsh ./hsh: 1: qwerty: not found $ echo "qwerty" | ./././hsh ./././hsh: 1: qwerty: not found $

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)

gcc -Wall -Werror -Wextra -pedantic -std=gnu89 *.c -o hsh

• README.md - description about the project repo
• man_1_simple_shell - is the man page for the shell we are going to write.
• AUTHORS - file at the root of your repository, listing all individuals having contributed content to the repository.
• main.h - is the header file which contains the standared header file and prototype of o function used in the program.
• main.c - initialize the program with infinite loop by call the prompt function
• prompt.c - it use getline system call to read the input from the user and run infinite loop with fork to keep prompt going.
• special_character - It identiies if the special inputs such as if the frist input is slash,the user typed exit or env...
• string.c -it handles the strings(string length, write string,find string in directory,concatane strings....)
• cmd.c - it finds the command the user entered.
• execute.c - execute the command.

Bash script for generating the list of authors in git repo

#!/bin/sh

git shortlog -se \
  | perl -spe 's/^\s+\d+\s+//' \
  | sed -e '/^CommitSyncScript.*$/d' \
  > AUTHORS