minishell

This project is about creating a simple shell. Well it's not that simple!

How to use

In a terminal, type in "make"
Then, type in "./minishell"
Use it like you would use bash!

Team name

SMBASH

Contributors

amarchan
abarrier

Content

Historic :clock7:
ToDo :dart:
Externals Functions
Sources :link:

Historic :clock7:

Go to content	Date YYYY-MM-DD	Description
2022-06-17	methodology alignment
2022-06-15	init README

ToDo :dart:

Go to content

[ ] Display a prompt when waiting for a new command
[ ] Have a working history
[ ] Search and launch the right executable (based on the PATH variable or using a relative or an absolute path)
[ ] Not use more than one global variable. Think about it. You will have to explain its purpose
[ ] Not interpret unclosed quotes or special characters which are not required by the subject such as \ (backslash) or ; (semicolon)
[ ] Handle ’ (single quote) which should prevent the shell from interpreting the meta-characters in the quoted sequence
[ ] Handle " (double quote) which should prevent the shell from interpreting the meta-characters in the quoted sequence except for $ (dollar sign)
[ ] Implement redirections
- [ ] < should redirect input
- [ ] > should redirect output
- [ ] << should be given a delimiter, then read the input until a line containing the delimiter is seen. However, it doesn’t have to update the history!
- [ ] >> should redirect output in append mode
[ ] Implement pipes (| character). The output of each command in the pipeline is connected to the input of the next command via a pipe.
[ ] Handle environment variables ($ followed by a sequence of characters) which should expand to their values
[ ] Handle $? which should expand to the exit status of the most recently executed foreground pipeline
[ ] Handle ctrl-C, ctrl-D and ctrl-\ which should behave like in bash
[ ] In interactive mode
- [ ] ctrl-C displays a new prompt on a new line
- [ ] ctrl-D exits the shell
- [ ] ctrl-\ does nothing
[ ] Your shell must implement the following builtins
- [ ] echo with option -n
- [ ] cd with only a relative or absolute path
- [ ] pwd with no options
- [ ] export with no options
- [ ] unset with no options
- [ ] env with no options or arguments
- [ ] exit with no options

ToDo (officiO)

[ ] '?' '-' don't consider as word when exporting
[x] Use customized env_list in the whole minishell instead of char **envp from the main
[ ] Return case of built-in and commands
[x] Handle env_list as a char** if our minishell is call in the minishell itself ==> NO FUCKING IDEA
[ ] Finish correctly the function do_exit
[ ] Finish correctly the function do_cd
[ ] Handle HEREDOC with signal handling
[ ] Create the function $?
[ ] Check signal handling
[ ] Check the leaks
[ ] Norminette

:warning: The readline() function can cause memory leaks. You don’t have to fix them. But that doesn’t mean your own code, yes the code you wrote, can have memory leaks.

Env

The command allows you to run another program in a custom environment without modifying the current one. When used without an argument it will print a list of the current environment variables.

:warning The command will change the env list only for the active command no matters if several pipes

:pushpin: Normal behaviour of env process if pipe due to fork which duplicates the vqriqbles before to execute the commqnd

Syntax

env
env ENV_NAME=value
env ENV_NAME=value <command>

Rules

If no ENV_NAME ==> Display env list as following ENV_NAME=value
If ENV_NAME is specified and already existing in env list, always store its value ==>
ENV_NAME must start by [a-z;A-Z;0-9;_;@] ==> To be confirmed on LINUX system
ENV_NAME must finish by [a-z;A-Z;0-9;_;@;-] ==> To be confirmed on LINUX system
ENV_NAME can have escape character [\;-;+] ==> To be confirmed on LINUX system

ENV_NAME can have expansion process

export antho=cia
export al$antho=tata
env | sort | grep 'al'
alicia=tata

ENV_NAME value can be appended by using expansion process and only with field separator [@-:.,]
If ENV_NAME is specified and already existing in env list, always reetore its original value (see step 2)

:warning: ENV_NAME is case sensitive
:warning: append existing variable which does not exist will create it only during the flow of command if command argument exists

Export

The command sets environment variables.

:warning The command will change the env list only for the active command only if several pipes. Otherwise the env list is changed

:pushpin: Normal behaviour of export process if pipe due to fork which duplicates the vqriqbles before to execute the commqnd

Example: export ANTHO=tata ==> will update/create the env AMTHO into the env list export ANTHO=tata | echo $ANTHO ==> will update/create the env ANTHO only for the active command

Syntax

export
export ENV_NAME=value
export ENV_NAME=$EXISTING_ENV:value

Rules

If no ENV_NAME ==> Display env list as following declare -x ENV_NAME=value
ENV_NAME must start by [a-z;A-Z;_]
ENV_NAME must finish by [a-z;A-Z;0-9;_]
ENV_NAME can have escape character [\]

ENV_NAME can have expansion process

export antho=cia
export al$antho=tata
env | sort | grep 'al'
alicia=tata

ENV_NAME value can be appended by using expansion process and only with field separator [@-:.,]

:warning: ENV_NAME is case sensitive
:warning: append existing variable which does not exist will create it

Externals functions

readline, rl_clear_history, rl_on_new_line,
rl_replace_line, rl_redisplay, add_history,
printf, malloc, free, write, access, open, read,
close, fork, wait, waitpid, wait3, wait4, signal,
sigaction, sigemptyset, sigaddset, kill, exit,
getcwd, chdir, stat, lstat, fstat, unlink, execve,
dup, dup2, pipe, opendir, readdir, closedir,
strerror, perror, isatty, ttyname, ttyslot, ioctl,
getenv, tcsetattr, tcgetattr, tgetent, tgetflag,
tgetnum, tgetstr, tgoto, tputs

readline

:mag: To learn

rl_clear_history

:mag: To learn

rl_on_new_line

:mag: To learn

rl_replace_line

:mag: To learn

rl_redisplay

:mag: To learn

add_history

:mag: To learn

printf

:mag: To learn

malloc

:mag: To learn

free

:mag: To learn

write

:mag: To learn

access

:mag: Use to check permission right on object (files/directory) :video_game: pipex Link

open

:mag: To learn

read

:mag: To learn

close

:mag: To learn

fork

:mag: Use to clone the active process to a child process :video_game: pipex Link

wait

:mag: Use to wait a specific process :video_game: pipex Link

waitpid

:mag: Use to wait a specific process :video_game: pipex Link

wait3

:mag: Obsolete

wait4

:mag: Obsolete

signal

:mag: Overview of signals Link

sigaction

:mag: Examine and change a signal action Link

sigemptyset

:mag: Initialize and empty a signal set Link

sigaddset

:mag: Add a signal to a signal set Link

kill

:mag: To learn

exit

:mag: To learn

getcwd

:mag: To learn

chdir

:mag: To learn

stat

:mag: To learn

lstat

:mag: To learn

fstat

:mag: To learn

unlink

:mag: To learn

execve

:mag: Use to execute a command :video_game: pipex

dup

:mag: Use to create a new file descriptor according to an existing one :video_game: pipex

dup2

:mag: Use to "replace" an existing file descriptor from another existing one :video_game: pipex

pipe

:mag: Use to create two new file descriptor which can communicate through different process :video_game: pipex

opendir

:mag: To learn

readir

:mag: To learn

closedir

:mag: To learn

strerror

:mag: To learn

perror

:mag: To learn

isatty

:mag: Test whether a file descriptor refers to a terminal

ttyname

:mag: Return name of a terminal

ttyslot

:mag: Find the slot of the current user's terminal in some file

ioctl

:mag: Control device. To learn

getenv

:mag: Get an environment variable

tcsetattr

:mag: Set the parameters associated with the terminal Link

tcgetattr

:mag: Get the parameters associated with the terminal Link

tgetent

:mag: To learn -->WTF ?

tgetflag

:mag: To learn -->WTF ?

tgetnum

:mag: To learn -->WTF ?

tgetstr

:mag: To learn -->WTF ?

tgoto

:mag: To learn -->WTF ?

tputs

:mag: To learn -->WTF ?

Sources :link:

Go to content

Bash

Builtins

Export

https://www.baeldung.com/linux/bash-variables-export

Git

https://github.com/BarrierAntho/Survivor_Note/tree/main/git

Parser

Shell

https://explainshell.com/

Signal

https://linuxhint.com/signal_handlers_c_programming_language/

Alicia-bites / minishell

readme

minishell

How to use

Team name

Contributors

Content

Historic :clock7:

ToDo :dart:

ToDo (officiO)

Env

Syntax

Rules

Export

Syntax

Rules

Externals functions

readline

rl_clear_history

rl_on_new_line

rl_replace_line

rl_redisplay

add_history

printf

malloc

free

write

access

open

read

close

fork

wait

waitpid

wait3

wait4

signal

sigaction

sigemptyset

sigaddset

kill

exit

getcwd

chdir

stat

lstat

fstat

unlink

execve

dup

dup2

pipe

opendir

readir

closedir

strerror

perror

isatty

ttyname

ttyslot

ioctl

getenv

tcsetattr

tcgetattr

tgetent

tgetflag

tgetnum

tgetstr

tgoto

tputs

Sources :link:

Bash

Builtins

Export

Git

Parser

Shell

Signal