A simple UNIX command interpreter project by Hannah Muthoni - https://github.com/root-h and Lilian Wanjiku - https://github.com/Lilywd
- 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 equival ent 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)
Your shell will be compiled this way:
gcc -Wall -Werror -Wextra -pedantic -std=gnu89 *.c -o hsh
Your 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
$
prompt.c
Write a beautiful code that passes the Betty checks
hsh.c
Write a UNIX command line interpreter.
Usage:
simple_shell
Your Shell should:
- Display a prompt and wait for the user to type a command. A command line always ends with a new line.
- The prompt is displayed again each time a command has been executed.
- The command lines are simple, no semicolons, no pipes, no redirections or any other advanced features.
- The command lines are made only of one word. No arguments will be passed to programs.
- If an executable cannot be found, print an error message and display the prompt again.
- Handle errors.
- You have to handle the “end of file” condition (Ctrl+D)
You don’t have to:
- use the PATH
- implement built-ins
- handle special characters :
", ', `, \, *, &, #
- be able to move the cursor
- handle commands with arguments
julien@ubuntu:~/shell$ ./shell
#cisfun$ ls
./shell: No such file or directory
#cisfun$ /bin/ls
barbie_j env-main.c exec.c fork.c pid.c ppid.c prompt prompt.c shell.c stat.c wait
env-environ.c exec fork mypid ppid printenv promptc shell stat test_scripting.sh wait.c
#cisfun$ /bin/ls -l
./shell: No such file or directory
#cisfun$ ^[[D^[[D^[[D
./shell: No such file or directory
#cisfun$ ^[[C^[[C^[[C^[[C
./shell: No such file or directory
#cisfun$ exit
./shell: No such file or directory
#cisfun$ ^C
julien@ubuntu:~/shell$ echo "/bin/ls" | ./shell
#cisfun$ barbie_j env-main.c exec.c fork.c pid.c ppid.c prompt prompt.c shell.c stat.c wait
env-environ.c exec fork mypid ppid printenv promptc shell stat test_scripting.sh wait.c
#cisfun$ julien@ubuntu:~/shell$
tokenizer.c
Simple shell 0.1
- Handle command lines with arguments
_which.c
Simple shell 0.2
- Handle the
PATH
fork
must not be called if the command doesn’t exist
julien@ubuntu:~/shell$ ./shell_0.3
:) /bin/ls
barbie_j env-main.c exec.c fork.c pid.c ppid.c prompt prompt.c shell_0.3 stat test_scripting.sh wait.c
env-environ.c exec fork mypid ppid printenv promptc shell shell.c stat.c wait
:) ls
barbie_j env-main.c exec.c fork.c pid.c ppid.c prompt prompt.c shell_0.3 stat test_scripting.sh wait.c
env-environ.c exec fork mypid ppid printenv promptc shell shell.c stat.c wait
:) ls -l /tmp
total 20
-rw------- 1 julien julien 0 Dec 5 12:09 config-err-aAMZrR
drwx------ 3 root root 4096 Dec 5 12:09 systemd-private-062a0eca7f2a44349733e78cb4abdff4-colord.service-V7DUzr
drwx------ 3 root root 4096 Dec 5 12:09 systemd-private-062a0eca7f2a44349733e78cb4abdff4-rtkit-daemon.service-ANGvoV
drwx------ 3 root root 4096 Dec 5 12:07 systemd-private-062a0eca7f2a44349733e78cb4abdff4-systemd-timesyncd.service-CdXUtH
-rw-rw-r-- 1 julien julien 0 Dec 5 12:09 unity_support_test.0
:) ^C
julien@ubuntu:~/shell$
builtins.c
Simple shell 0.3
- Implement the
exit
built-in, that exits the shell - Usage:
exit
- You don’t have to handle any argument to the built-in
exit
_getenv.c
Simple shell 0.4
- Implement the
env
built-in, that prints the current environment
julien@ubuntu:~/shell$ ./simple_shell
$ env
USER=julien
LANGUAGE=en_US
SESSION=ubuntu
COMPIZ_CONFIG_PROFILE=ubuntu
SHLVL=1
HOME=/home/julien
C_IS=Fun_:)
DESKTOP_SESSION=ubuntu
LOGNAME=julien
TERM=xterm-256color
PATH=/home/julien/bin:/home/julien/.local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin
DISPLAY=:0
$ exit
julien@ubuntu:~/shell$