Minishell

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🚀 About

Minishell is a 42 school project that challenges you to recreate a simplified UNIX shell. This implementation supports pipes, redirections, environment variables, and other essential shell features - all while being limited to a select group of standard functions.

Realized by Androlink && WaRtr0

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🛠️ Installation

1. Clone with submodules:

   git clone --recursive https://github.com/WaRtr0/Minishell.git
   cd Minishell

2. Build:

   make
   

3. Run:

   ./minishell
   

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⚙️ Features

📜 Built-in Commands

Command	Options Supported
echo	-n (no newline)
cd	Relative/Absolute paths
pwd	No options
export	Variable assignment
unset	Variable removal
env	No arguments
exit	Exit with status code

🔄 Operators

Operator	Example
< (Input)	grep 'test' < file.txt
> (Output)	ls > output.txt
>> (Append)	echo "text" >> file.txt
<< (Here doc)	cat << LIMITER
| (Pipe)	ls | grep .c
&& (And)	make && ./app
|| (Or)	invalid_cmd || echo "Error"
() (Grouping)	(ls || echo Fail) && echo Done

🕹️ Interactive Mode

• Handles unclosed quotes/multiline commands
• Ctrl+C: New prompt on fresh line
• Ctrl+D: Clean exit
• Non-blocking Ctrl+\

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🔍 Debug Mode

You can compile Minishell in debug mode using the following command:

make debug

This enables DEBUG_MODE, which prints the Abstract Syntax Tree (AST) of the parsed command in a structured JSON format — useful for debugging and understanding how the shell interprets your input.

🧪 Example

For the command:

echo hello world! && true && (false || echo hello) && echo 1 | echo 2 | echo * > test

The AST will be displayed in JSON like this:

Click to show AST output (JSON)

[
	{
		"type": "14-CMD_JOIN",
		"content": [
			{ "type": "13-CMD_TEXT", "content": "echo" },
			{ "type": "16-CMD_EMPTY" },
			{ "type": "13-CMD_TEXT", "content": "hello" },
			{ "type": "16-CMD_EMPTY" },
			{ "type": "13-CMD_TEXT", "content": "world!" },
			{ "type": "16-CMD_EMPTY" }
		]
	},
	{
		"type": "6-CMD_AND_IF",
		"content": [
			{
				"type": "14-CMD_JOIN",
				"content": [
					{ "type": "13-CMD_TEXT", "content": "true" },
					{ "type": "16-CMD_EMPTY" }
				]
			}
		]
	},
	{
		"type": "6-CMD_AND_IF",
		"content": [
			{
				"type": "10-CMD_PARENTHESIS",
				"content": [
					{
						"type": "14-CMD_JOIN",
						"content": [
							{ "type": "13-CMD_TEXT", "content": "false" },
							{ "type": "16-CMD_EMPTY" }
						]
					},
					{
						"type": "8-CMD_OR",
						"content": [
							{
								"type": "14-CMD_JOIN",
								"content": [
									{ "type": "13-CMD_TEXT", "content": "echo" },
									{ "type": "16-CMD_EMPTY" },
									{ "type": "13-CMD_TEXT", "content": "hello" }
								]
							}
						]
					}
				]
			}
		]
	},
	{
		"type": "6-CMD_AND_IF",
		"content": [
			{
				"type": "0-CMD_PIPE",
				"content": [
					{
						"type": "14-CMD_JOIN",
						"content": [
							{ "type": "13-CMD_TEXT", "content": "echo" },
							{ "type": "16-CMD_EMPTY" },
							{ "type": "13-CMD_TEXT", "content": "1" },
							{ "type": "16-CMD_EMPTY" }
						]
					},
					{
						"type": "14-CMD_JOIN",
						"content": [
							{ "type": "13-CMD_TEXT", "content": "echo" },
							{ "type": "16-CMD_EMPTY" },
							{ "type": "13-CMD_TEXT", "content": "2" },
							{ "type": "16-CMD_EMPTY" }
						]
					},
					{
						"type": "14-CMD_JOIN",
						"content": [
							{ "type": "13-CMD_TEXT", "content": "echo" },
							{ "type": "16-CMD_EMPTY" },
							{ "type": "17-CMD_WILDCARD" },
							{ "type": "16-CMD_EMPTY" },
							{ "type": "2-CMD_REDIR_OUT", "content": 0 }, // init 0
							{ "type": "16-CMD_EMPTY" },
							{ "type": "13-CMD_TEXT", "content": "test" } // name file
						]
					}
				]
			}
		]
	}
]

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🔧 Constraints

• Limited functions
• Only 1 global variable allowed
• Strict 42 norm
• Zero memory leaks