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https://github.com/msabr/minishell_1337


https://github.com/msabr/minishell_1337

1337cursus 1337school 42cursus bash builtin command-line environment environment-variables error-handling execution file-descriptor minishell minishell-42 minishell-guide minishell42 parsing path-planning pathfinding pipeline shell

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README 

          
# Minishell - 42 Network










A minimal shell implementation in C that recreates basic bash functionality as part of the 42 School curriculum.



## 📋 Table of Contents



- [Overview](#overview)

- [Features](#features)

- [Prerequisites](#prerequisites)

- [Installation](#installation)

- [Usage](#usage)

- [Project Structure](#project-structure)

- [Implementation Details](#implementation-details)

- [Built-in Commands](#built-in-commands)

- [Testing](#testing)

- [Known Issues](#known-issues)

- [Authors](#authors)



## 🎯 Overview



Minishell is a simplified shell implementation that provides a command-line interface similar to bash. This project demonstrates understanding of:



- Process management and system calls

- Lexical analysis and parsing

- Signal handling

- File descriptor manipulation

- Memory management

- Inter-process communication



## ✨ Features



### Core Functionality

- **Interactive command prompt** with custom banner

- **Command execution** with PATH resolution

- **Pipe support** for command chaining (`|`)

- **Redirections**: 

  - Input redirection (`<`)

  - Output redirection (`>`)

  - Append redirection (`>>`)

  - Here-documents (`<<`)

- **Variable expansion** (`$VAR`, `$?`)

- **Quote handling** (single and double quotes)

- **Signal handling** (Ctrl+C, Ctrl+\, Ctrl+D)



### Built-in Commands

- `echo` (with `-n` flag)

- `cd` (with relative/absolute paths)

- `pwd`

- `export`

- `unset`

- `env`

- `exit`



### Advanced Features

- **Environment variable management**

- **Exit status tracking** (`$?`)

- **Syntax error detection**

- **Memory leak prevention**

- **History support** (via readline)



## 🔧 Prerequisites



- **GCC** or compatible C compiler

- **GNU Readline library**

- **Make**

- **macOS** (for brew-based readline installation)



## 🚀 Installation



1. **Clone the repository:**

   ```bash

   git clone git@github.com:msabr/minishell.git

   cd minishell

   ```



2. **Install readline (if not already installed):**

   ```bash

   make install-readline

   ```



3. **Compile the project:**

   ```bash

   make

   ```



4. **Run minishell:**

   ```bash

   make run

   # or

   ./minishell

   ```



## 💻 Usage



### Basic Commands

```bash

minishell$ echo "Hello, World!"

Hello, World!



minishell$ pwd

/path/to/current/directory



minishell$ ls -la | grep .c

# Lists all .c files in current directory

```



### Redirections

```bash

minishell$ echo "content" > file.txt

minishell$ cat < file.txt

content



minishell$ echo "more content" >> file.txt

minishell$ cat file.txt

content

more content

```



### Here-documents

```bash

minishell$ cat << EOF

> line 1

> line 2

> EOF

line 1

line 2

```



### Variable Operations

```bash

minishell$ export MY_VAR="hello"

minishell$ echo $MY_VAR

hello



minishell$ echo $?

0

```



## 📁 Project Structure



```

minishell/

├── Libft

│   ├── Makefile

│   ├── ft_atoi.c

│   ├── ft_bzero.c

│   ├── ft_calloc.c

│   ├── ft_free.c

│   ├── ft_is_number.c

│   ├── ft_isalnum.c

│   ├── ft_isalpha.c

│   ├── ft_isascii.c

│   ├── ft_isdigit.c

│   ├── ft_isprint.c

│   ├── ft_isspace.c

│   ├── ft_itoa.c

│   ├── ft_malloc.c

│   ├── ft_memchr.c

│   ├── ft_memcmp.c

│   ├── ft_memcpy.c

│   ├── ft_memmove.c

│   ├── ft_memset.c

│   ├── ft_putchar_fd.c

│   ├── ft_putendl_fd.c

│   ├── ft_putnbr_fd.c

│   ├── ft_putstr_fd.c

│   ├── ft_split.c

│   ├── ft_split_space.c

│   ├── ft_strcat.c

│   ├── ft_strchr.c

│   ├── ft_strcmp.c

│   ├── ft_strcpy.c

│   ├── ft_strdup.c

│   ├── ft_striteri.c

│   ├── ft_strjoin.c

│   ├── ft_strlcat.c

│   ├── ft_strlcpy.c

│   ├── ft_strlen.c

│   ├── ft_strmapi.c

│   ├── ft_strncmp.c

│   ├── ft_strndup.c

│   ├── ft_strnstr.c

│   ├── ft_strrchr.c

│   ├── ft_strrev.c

│   ├── ft_strstr.c

│   ├── ft_strtrim.c

│   ├── ft_substr.c

│   ├── ft_tolower.c

│   ├── ft_toupper.c

│   └── libft.h

├── Makefile

├── execution

│   ├── banner.c

│   ├── builtins

│   │   ├── builtins.c

│   │   ├── builtins.h

│   │   ├── cd.c

│   │   ├── echo.c

│   │   ├── env.c

│   │   ├── exit.c

│   │   ├── export.c

│   │   ├── export_files.c

│   │   ├── pwd.c

│   │   └── unset.c

│   ├── environment

│   │   ├── file1.c

│   │   ├── file2.c

│   │   └── file3.c

│   ├── execution.h

│   ├── exit_status.c

│   ├── file_descriptor.c

│   ├── main_loop.c

│   ├── path_functions.c

│   ├── path_functions_1.c

│   ├── pipe

│   │   ├── handel_pipe1.c

│   │   ├── handel_pipe2.c

│   │   ├── handel_pipe3.c

│   │   ├── handel_pipe4.c

│   │   └── pipe.h

│   ├── print_errors.c

│   ├── redirection

│   │   ├── redirect_append.c

│   │   ├── redirect_heredoc.c

│   │   ├── redirect_heredoc_1.c

│   │   ├── redirect_overwrite.c

│   │   ├── redirect_stdin.c

│   │   ├── redirection.h

│   │   └── redirection_files.c

│   ├── signals.c

│   └── simple_cmd.c

├── main.c

├── minishell.h

└── parsing

    ├── check_syntax

    │   ├── syntax_error.c

    │   └── syntax_tool.c

    ├── expension2

    │   ├── expend_helper.c

    │   ├── expend_helper2.c

    │   ├── expend_helper3.c

    │   ├── expend_helper4.c

    │   ├── expend_herdoc.c

    │   ├── expend_utils.c

    │   ├── expend_utils2.c

    │   ├── expend_utils3.c

    │   ├── expend_utils4.c

    │   ├── expend_utils5.c

    │   └── expension.c

    ├── lexing

    │   ├── lexer.c

    │   ├── lexer_handler2.c

    │   ├── lexer_handlers.c

    │   ├── lexer_utils.c

    │   └── token_utils.c

    ├── parse_cmd

    │   ├── export_parse.c

    │   ├── parse_utils.c

    │   ├── parse_utils2.c

    │   ├── parse_utils3.c

    │   ├── parser.c

    │   └── parser_helper.c

    ├── parse_input.c

    └── parsing.h



12 directories, 111 files

```



## 🔍 Implementation Details



### Parsing Pipeline

1. **Lexical Analysis**: Tokenizes input into meaningful units

2. **Expansion**: Handles variable substitution and quote removal

3. **Syntax Checking**: Validates command structure

4. **Command Building**: Constructs executable command structures



### Key Data Structures



```c

typedef struct s_cmd {

    char         **args;     // Command arguments

    t_redir      *redirs;    // Redirections list

    bool         in_pipe;    // Pipe context flag

    struct s_cmd *next;      // Next command in pipeline

} t_cmd;



typedef struct s_env {

    char         *key;              // Variable name

    char         *value;            // Variable value

    bool         export_variable;   // Export flag

    struct s_env *next;             // Next environment variable

} t_env;

```



### Memory Management

- Custom memory allocation tracking via `ft_malloc`/`ft_free`

- Automatic cleanup on exit

- Prevention of memory leaks through proper deallocation



## 🔨 Built-in Commands



| Command | Description | Usage |

|---------|-------------|-------|

| `echo` | Display text | `echo [-n] [text...]` |

| `cd` | Change directory | `cd [path]` |

| `pwd` | Print working directory | `pwd` |

| `export` | Set environment variables | `export [VAR=value]` |

| `unset` | Remove environment variables | `unset [VAR]` |

| `env` | Display environment | `env` |

| `exit` | Exit the shell | `exit [status]` |



## 🧪 Testing



### Basic Testing

```bash

# Test basic commands

minishell$ echo hello world

minishell$ pwd

minishell$ cd /tmp

minishell$ pwd



# Test pipes

minishell$ echo "test" | cat | cat



# Test redirections

minishell$ echo "test" > file && cat file



# Test variables

minishell$ export TEST=value

minishell$ echo $TEST

```



### Error Handling

```bash

# Test syntax errors

minishell$ echo |

minishell$ cat <



# Test command not found

minishell$ nonexistent_command



# Test directory execution

minishell$ ./directory_name

```



## 🏗️ Build Options



- **Debug mode**: Uncomment `-g3 -fsanitize=address,undefined` in Makefile

- **Clean build**: `make fclean && make`

- **Rebuild**: `make re`



## ⚠️ Known Issues



- Limited error handling for edge cases

- Some advanced bash features not implemented

- Platform-specific (macOS-oriented due to brew readline)



## 🤝 Contributing



1. Fork the repository

2. Create a feature branch (`git checkout -b feature/amazing-feature`)

3. Commit your changes (`git commit -m 'Add amazing feature'`)

4. Push to the branch (`git push origin feature/amazing-feature`)

5. Open a Pull Request



## 📄 License



This project is part of the 42 School curriculum. Please respect academic integrity guidelines.



## 👥 Authors



- **msabr** - Main developer

- **kabouelf** - Contributor

  

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```