Warning
This repository is not the actual project side.
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”?
- Copyright - Plagiarism
- You are tasked to come up with solutions for the tasks below yourself to meet with the above learning objectives.
- You will not be able to meet the objectives of this or any following project by copying and pasting someone else’s - work.
- You are not allowed to publish any content of this project.
- Any form of plagiarism is strictly forbidden and will result in removal from the program.
- 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?)
- 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 GitHub
Important
*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. *
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)
$ 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)
Your shell will be compiled this way:
gcc -Wall -Werror -Wextra -pedantic -std=gnu89 *.c -o hshYour shell should work like this in interactive mode:
$ ./hsh
($) /bin/ls
hsh main.c shell.c
($)
($) exit
$But also in non-interactive mode:
$ echo "/bin/ls" | ./hsh
hsh main.c shell.c test_ls_2
$
$ cat test_ls_2
/bin/ls
/bin/ls
$
$ cat test_ls_2 | ./hsh
hsh main.c shell.c test_ls_2
hsh main.c shell.c test_ls_2
$