simple_shell 💻

Description

This program is shell-based, that is, it behaves like a command line interpreter. Like Shell, this program receives input, interprets it for the operating system, and manages the output.

Usage

1. Clone the repository:

   git clone https://github.com/yuriquezada/simple_shell.git
   

2. Locate ourselves in the root folder of the directory.

3. Inside the simple_shell folder, run the following command:

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

4. Finally run the program by typing the following:

   ./shell
   

   The output of the new shell is the following:

   julien@ubuntu:~/shell$./shell
   $
   

Project structure

File	Description
README.md	Contains summary and key information about this project.
AUTHORS	List all the people who have contributed content to the repository
man_1_simple_shell	Display the user manual of any command that we can run on the terminal. It provides a detailed view of the command which includes NAME, SYNOPSIS, DESCRIPTION, BUGS, SEE ALSO, NOTES, and AUTHORS
hack/generate-authors.sh	Generates the list of project authors
shell	Allows us to run the new Shell
file.h	Contains C function declarations and macro definitions to be shared between several source files
main.c	Contains our main() function
tokenizer.c	It receives an input in the shell and identifies each value entered
matcher.c	Relates the input entered with the function to be executed in shell
prints.c	Prints the octal unsigned integer conversion
free.c	Contains the function to free up memory
env.c	Prints the environment of the current process

Example

If we want to print all the variables of the current environment, we will write env in our new shell

user@ubuntu:~/shell$ ./shell
$ env
HOSTNAME=ef1189cc98cb
LANGUAGE=en_US:en
PWD=/root/simple_shell
TZ=America/Los_Angeles
HOME=/root
LANG=en_US.UTF-8
LS_COLORS=rs=0:di=01;34:ln=01;36:mh=00:pi=40;33:so=01;35:do=01;35:bd=40;33;01:cd                            =40;33;01:or=40;31;01:mi=00:su=37;41:sg=30;43:ca=30;41:tw=30;42:ow=34;42:st=37;4                            4:ex=01;32:*.tar=01;31:*.tgz=01;31:*.arc=01;31:*.arj=01;31:*.taz=01;31:*.lha=01;                            31:*.lz4=01;31:*.lzh=01;31:*.lzma=01;31:*.tlz=01;31:*.txz=01;31:*.tzo=01;31:*.t7                            z=01;31:*.zip=01;31:*.z=01;31:*.dz=01;31:*.gz=01;31:*.lrz=01;31:*.lz=01;31:*.lzo                            =01;31:*.xz=01;31:*.zst=01;31:*.tzst=01;31:*.bz2=01;31:*.bz=01;31:*.tbz=01;31:*.                            tbz2=01;31:*.tz=01;31:*.deb=01;31:*.rpm=01;31:*.jar=01;31:*.war=01;31:*.ear=01;3                            1:*.sar=01;31:*.rar=01;31:*.alz=01;31:*.ace=01;31:*.zoo=01;31:*.cpio=01;31:*.7z=                            01;31:*.rz=01;31:*.cab=01;31:*.wim=01;31:*.swm=01;31:*.dwm=01;31:*.esd=01;31:*.j                            pg=01;35:*.jpeg=01;35:*.mjpg=01;35:*.mjpeg=01;35:*.gif=01;35:*.bmp=01;35:*.pbm=0                            1;35:*.pgm=01;35:*.ppm=01;35:*.tga=01;35:*.xbm=01;35:*.xpm=01;35:*.tif=01;35:*.t                            iff=01;35:*.png=01;35:*.svg=01;35:*.svgz=01;35:*.mng=01;35:*.pcx=01;35:*.mov=01;                            35:*.mpg=01;35:*.mpeg=01;35:*.m2v=01;35:*.mkv=01;35:*.webm=01;35:*.ogm=01;35:*.m                            p4=01;35:*.m4v=01;35:*.mp4v=01;35:*.vob=01;35:*.qt=01;35:*.nuv=01;35:*.wmv=01;35                            :*.asf=01;35:*.rm=01;35:*.rmvb=01;35:*.flc=01;35:*.avi=01;35:*.fli=01;35:*.flv=0                            1;35:*.gl=01;35:*.dl=01;35:*.xcf=01;35:*.xwd=01;35:*.yuv=01;35:*.cgm=01;35:*.emf                            =01;35:*.ogv=01;35:*.ogx=01;35:*.aac=00;36:*.au=00;36:*.flac=00;36:*.m4a=00;36:*                            .mid=00;36:*.midi=00;36:*.mka=00;36:*.mp3=00;36:*.mpc=00;36:*.ogg=00;36:*.ra=00;36:*.wav=00;36:*.oga=00;36:*.opus=00;36:*.spx=00;36:*.xspf=00;36:
LESSCLOSE=/usr/bin/lesspipe %s %s
TERM=xterm
LESSOPEN=| /usr/bin/lesspipe %s
SHLVL=1
LC_ALL=en_US.UTF-8
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
OLDPWD=/root/simple_shell/hack
_=./shell
$

Tasks

0. README, man, AUTHORS

• Write a README
• Write a man for your shell.
• You should have an AUTHORS file at the root of your repository, listing all individuals having contributed content to the repository. Format, see Docker |

Repo:

• GitHub repository: simple_shell
• File: README.md, man_1_simple_shell, AUTHORS

1. Betty would be proud

Write a beautiful code that passes the Betty checks Repo:

• GitHub repository: simple_shell

2. Simple shell 0.1

• 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$

Repo:

• GitHub repository: simple_shell

3. Simple shell 0.2

Simple shell 0.1 +

• Handle command lines with arguments

Repo:

• GitHub repository: simple_shell

4. Simple shell 0.3

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$ 

Repo:

• GitHub repository: simple_shell

5. Simple shell 0.4

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

Repo:

• GitHub repository: simple_shell

6. Simple shell 1.0

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$ 

Repo:

• GitHub repository: simple_shell

Authors ✏️

Rayd Trujillo - rayd1893

Yuri Quezada - yuriquezada