bellos

.gitignore

@@ -0,0 +1,4 @@
+publish.sh
+Cargo.toml
+Cargo.lock
+target

README.md

@@ -12,7 +12,157 @@
 - Environment variables
 - redirection support
 
+## BELLOS Usage
+```
+#!/usr/bin/env bellos
+# File: hello_world.bellos
 
+# Simple Hello World script
+echo "Hello, World!"
+
+# Using variables
+name="Bellos"
+echo "Welcome to $name programming!"
+
+# ----------------------------------------
+
+#!/usr/bin/env bellos
+# File: basic_math.bellos
+
+# Demonstrating arithmetic operations
+a=5
+b=3
+
+sum=$((a + b))
+difference=$((a - b))
+product=$((a * b))
+quotient=$((a / b))
+
+echo "Sum: $sum"
+echo "Difference: $difference"
+echo "Product: $product"
+echo "Quotient: $quotient"
+
+# ----------------------------------------
+
+#!/usr/bin/env bellos
+# File: control_structures.bellos
+
+# Demonstrating if statements and loops
+
+# If statement
+if [ $# -eq 0 ]
+then
+    echo "No arguments provided"
+elif [ $# -eq 1 ]
+then
+    echo "One argument provided: $1"
+else
+    echo "Multiple arguments provided"
+fi
+
+# For loop
+echo "Counting from 1 to 5:"
+for i in 1 2 3 4 5
+do
+    echo $i
+done
+
+# While loop
+echo "Countdown:"
+count=5
+while [ $count -gt 0 ]
+do
+    echo $count
+    count=$((count - 1))
+done
+
+# ----------------------------------------
+
+#!/usr/bin/env bellos
+# File: functions.bellos
+
+# Defining and using functions
+
+function greet() {
+    echo "Hello, $1!"
+}
+
+function add() {
+    echo $(($1 + $2))
+}
+
+# Calling functions
+greet "User"
+result=$(add 3 4)
+echo "3 + 4 = $result"
+
+# ----------------------------------------
+
+#!/usr/bin/env bellos
+# File: file_operations.bellos
+
+# Demonstrating file operations
+
+# Writing to a file
+echo "This is a test file" > test.txt
+echo "Adding another line" >> test.txt
+
+# Reading from a file
+echo "Contents of test.txt:"
+cat test.txt
+
+# Using a while loop to read file line by line
+echo "Reading file line by line:"
+while read -r line
+do
+    echo "Line: $line"
+done < test.txt
+
+# Cleaning up
+rm test.txt
+
+# ----------------------------------------
+
+#!/usr/bin/env bellos
+# File: string_manipulation.bellos
+
+# Demonstrating string manipulation
+
+string="Hello, Bellos!"
+
+# String length
+echo "Length of string: ${#string}"
+
+# Substring
+echo "First 5 characters: ${string:0:5}"
+
+# String replacement
+new_string=${string/Bellos/World}
+echo "Replaced string: $new_string"
+
+# Converting to uppercase
+echo "Uppercase: ${string^^}"
+
+# Converting to lowercase
+echo "Lowercase: ${string,,}"
+```
+
+## Website NPM
+- https://crates.io/crates/bellos
+
+### Installation
+- `cargo add bellos`
+
+```
+Name: bellos
+Version: 0.0.1
+Summary: Bellande Operating System Scripting Programming Language
+Home-page: github.com/RonaldsonBellande/bellos
+Author: Ronaldson Bellande
+Author-email: ronaldsonbellande@gmail.com
+License: GNU General Public License v3.0
+```
 
 ## License
 

git_scripts/.gitignore

@@ -0,0 +1,3 @@
+fix_errors.sh
+push.sh
+repository_recal.sh

src/bellos.rs

@@ -0,0 +1,765 @@
+// Copyright (C) 2024 Bellande Architecture Mechanism Research Innovation Center, Ronaldson Bellande
+
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+use glob::glob;
+use std::collections::HashMap;
+use std::env;
+use std::fs::{self, File};
+use std::io::{self, Read, Write};
+use std::os::unix::io::AsRawFd;
+use std::process::{Child, Command, Stdio};
+use std::sync::{Arc, Mutex};
+use std::thread;
+
+#[derive(Debug, Clone, PartialEq)]
+enum Token {
+    Word(String),
+    Assignment,
+    Pipe,
+    Redirect(String),
+    LeftParen,
+    RightParen,
+    Semicolon,
+    NewLine,
+    If,
+    Then,
+    Else,
+    Fi,
+    While,
+    Do,
+    Done,
+    For,
+    In,
+    Function,
+    Ampersand,
+}
+
+#[derive(Debug, Clone)]
+enum ASTNode {
+    Command {
+        name: String,
+        args: Vec<String>,
+    },
+    Assignment {
+        name: String,
+        value: String,
+    },
+    Pipeline(Vec<ASTNode>),
+    Redirect {
+        node: Box<ASTNode>,
+        direction: String,
+        target: String,
+    },
+    Block(Vec<ASTNode>),
+    If {
+        condition: Box<ASTNode>,
+        then_block: Box<ASTNode>,
+        else_block: Option<Box<ASTNode>>,
+    },
+    While {
+        condition: Box<ASTNode>,
+        block: Box<ASTNode>,
+    },
+    For {
+        var: String,
+        list: Vec<String>,
+        block: Box<ASTNode>,
+    },
+    Function {
+        name: String,
+        body: Box<ASTNode>,
+    },
+    Background(Box<ASTNode>),
+}
+
+struct Lexer {
+    input: Vec<char>,
+    position: usize,
+}
+
+impl Lexer {
+    fn new(input: String) -> Self {
+        Lexer {
+            input: input.chars().collect(),
+            position: 0,
+        }
+    }
+
+    fn next_token(&mut self) -> Option<Token> {
+        self.skip_whitespace();
+
+        if self.position >= self.input.len() {
+            return None;
+        }
+
+        match self.input[self.position] {
+            '=' => {
+                self.position += 1;
+                Some(Token::Assignment)
+            }
+            '|' => {
+                self.position += 1;
+                Some(Token::Pipe)
+            }
+            '>' => {
+                self.position += 1;
+                Some(Token::Redirect(">".to_string()))
+            }
+            '<' => {
+                self.position += 1;
+                Some(Token::Redirect("<".to_string()))
+            }
+            '(' => {
+                self.position += 1;
+                Some(Token::LeftParen)
+            }
+            ')' => {
+                self.position += 1;
+                Some(Token::RightParen)
+            }
+            ';' => {
+                self.position += 1;
+                Some(Token::Semicolon)
+            }
+            '\n' => {
+                self.position += 1;
+                Some(Token::NewLine)
+            }
+            '&' => {
+                self.position += 1;
+                Some(Token::Ampersand)
+            }
+            '"' => Some(self.read_string()),
+            _ => Some(self.read_word()),
+        }
+    }
+
+    fn skip_whitespace(&mut self) {
+        while self.position < self.input.len() && self.input[self.position].is_whitespace() {
+            self.position += 1;
+        }
+    }
+
+    fn read_word(&mut self) -> Token {
+        let start = self.position;
+        while self.position < self.input.len()
+            && !self.input[self.position].is_whitespace()
+            && !matches!(
+                self.input[self.position],
+                '=' | '|' | '>' | '<' | '(' | ')' | ';' | '&' | '\n'
+            )
+        {
+            self.position += 1;
+        }
+        let word: String = self.input[start..self.position].iter().collect();
+        match word.as_str() {
+            "if" => Token::If,
+            "then" => Token::Then,
+            "else" => Token::Else,
+            "fi" => Token::Fi,
+            "while" => Token::While,
+            "do" => Token::Do,
+            "done" => Token::Done,
+            "for" => Token::For,
+            "in" => Token::In,
+            "function" => Token::Function,
+            _ => Token::Word(word),
+        }
+    }
+
+    fn read_string(&mut self) -> Token {
+        self.position += 1; // Skip opening quote
+        let start = self.position;
+        while self.position < self.input.len() && self.input[self.position] != '"' {
+            self.position += 1;
+        }
+        let result = Token::Word(self.input[start..self.position].iter().collect());
+        self.position += 1; // Skip closing quote
+        result
+    }
+}
+
+struct Parser {
+    tokens: Vec<Token>,
+    position: usize,
+}
+
+impl Parser {
+    fn new(tokens: Vec<Token>) -> Self {
+        Parser {
+            tokens,
+            position: 0,
+        }
+    }
+
+    fn parse(&mut self) -> Result<Vec<ASTNode>, String> {
+        let mut nodes = Vec::new();
+        while self.position < self.tokens.len() {
+            nodes.push(self.parse_statement()?);
+            self.consume_if(Token::Semicolon);
+            self.consume_if(Token::NewLine);
+        }
+        Ok(nodes)
+    }
+
+    fn parse_statement(&mut self) -> Result<ASTNode, String> {
+        match &self.tokens[self.position] {
+            Token::Word(_) => self.parse_command_or_assignment(),
+            Token::LeftParen => self.parse_block(),
+            Token::If => self.parse_if(),
+            Token::While => self.parse_while(),
+            Token::For => self.parse_for(),
+            Token::Function => self.parse_function(),
+            _ => Err(format!(
+                "Unexpected token: {:?}",
+                self.tokens[self.position]
+            )),
+        }
+    }
+
+    fn parse_command_or_assignment(&mut self) -> Result<ASTNode, String> {
+        let name = match &self.tokens[self.position] {
+            Token::Word(w) => w.clone(),
+            _ => {
+                return Err(format!(
+                    "Expected word, found {:?}",
+                    self.tokens[self.position]
+                ))
+            }
+        };
+        self.position += 1;
+
+        if self.position < self.tokens.len() && self.tokens[self.position] == Token::Assignment {
+            self.position += 1;
+            let value = match &self.tokens[self.position] {
+                Token::Word(w) => w.clone(),
+                _ => {
+                    return Err(format!(
+                        "Expected word after assignment, found {:?}",
+                        self.tokens[self.position]
+                    ))
+                }
+            };
+            self.position += 1;
+            Ok(ASTNode::Assignment { name, value })
+        } else {
+            let mut args = Vec::new();
+            while self.position < self.tokens.len()
+                && !matches!(
+                    self.tokens[self.position],
+                    Token::Pipe
+                        | Token::Redirect(_)
+                        | Token::Semicolon
+                        | Token::NewLine
+                        | Token::Ampersand
+                )
+            {
+                if let Token::Word(w) = &self.tokens[self.position] {
+                    args.push(w.clone());
+                    self.position += 1;
+                } else {
+                    break;
+                }
+            }
+            let command = ASTNode::Command { name, args };
+            self.parse_pipeline_or_redirect(command)
+        }
+    }
+
+    fn parse_pipeline_or_redirect(&mut self, left: ASTNode) -> Result<ASTNode, String> {
+        if self.position >= self.tokens.len() {
+            return Ok(left);
+        }
+
+        match &self.tokens[self.position] {
+            Token::Pipe => {
+                self.position += 1;
+                let right = self.parse_command_or_assignment()?;
+                let pipeline = ASTNode::Pipeline(vec![left, right]);
+                self.parse_pipeline_or_redirect(pipeline)
+            }
+            Token::Redirect(direction) => {
+                self.position += 1;
+                let target = match &self.tokens[self.position] {
+                    Token::Word(w) => w.clone(),
+                    _ => {
+                        return Err(format!(
+                            "Expected word after redirect, found {:?}",
+                            self.tokens[self.position]
+                        ))
+                    }
+                };
+                self.position += 1;
+                let redirect = ASTNode::Redirect {
+                    node: Box::new(left),
+                    direction: direction.clone(),
+                    target,
+                };
+                self.parse_pipeline_or_redirect(redirect)
+            }
+            Token::Ampersand => {
+                self.position += 1;
+                Ok(ASTNode::Background(Box::new(left)))
+            }
+            _ => Ok(left),
+        }
+    }
+
+    fn parse_block(&mut self) -> Result<ASTNode, String> {
+        self.position += 1; // Consume left paren
+        let mut statements = Vec::new();
+        while self.position < self.tokens.len() && self.tokens[self.position] != Token::RightParen {
+            statements.push(self.parse_statement()?);
+            self.consume_if(Token::Semicolon);
+            self.consume_if(Token::NewLine);
+        }
+        self.position += 1; // Consume right paren
+        Ok(ASTNode::Block(statements))
+    }
+
+    fn parse_if(&mut self) -> Result<ASTNode, String> {
+        self.position += 1; // Consume 'if'
+        let condition = Box::new(self.parse_statement()?);
+        self.expect_token(Token::Then)?;
+        let then_block = Box::new(self.parse_block()?);
+        let else_block = if self.consume_if(Token::Else) {
+            Some(Box::new(self.parse_block()?))
+        } else {
+            None
+        };
+        self.expect_token(Token::Fi)?;
+        Ok(ASTNode::If {
+            condition,
+            then_block,
+            else_block,
+        })
+    }
+
+    fn parse_while(&mut self) -> Result<ASTNode, String> {
+        self.position += 1; // Consume 'while'
+        let condition = Box::new(self.parse_statement()?);
+        self.expect_token(Token::Do)?;
+        let block = Box::new(self.parse_block()?);
+        self.expect_token(Token::Done)?;
+        Ok(ASTNode::While { condition, block })
+    }
+
+    fn parse_for(&mut self) -> Result<ASTNode, String> {
+        self.position += 1; // Consume 'for'
+        let var = match &self.tokens[self.position] {
+            Token::Word(w) => w.clone(),
+            _ => {
+                return Err(format!(
+                    "Expected variable name after 'for', found {:?}",
+                    self.tokens[self.position]
+                ))
+            }
+        };
+        self.position += 1;
+        self.expect_token(Token::In)?;
+        let mut list = Vec::new();
+        while self.position < self.tokens.len() && self.tokens[self.position] != Token::Do {
+            if let Token::Word(w) = &self.tokens[self.position] {
+                list.push(w.clone());
+                self.position += 1;
+            } else {
+                break;
+            }
+        }
+        self.expect_token(Token::Do)?;
+        let block = Box::new(self.parse_block()?);
+        self.expect_token(Token::Done)?;
+        Ok(ASTNode::For { var, list, block })
+    }
+
+    fn parse_function(&mut self) -> Result<ASTNode, String> {
+        self.position += 1; // Consume 'function'
+        let name = match &self.tokens[self.position] {
+            Token::Word(w) => w.clone(),
+            _ => {
+                return Err(format!(
+                    "Expected function name, found {:?}",
+                    self.tokens[self.position]
+                ))
+            }
+        };
+        self.position += 1;
+        let body = Box::new(self.parse_block()?);
+        Ok(ASTNode::Function { name, body })
+    }
+
+    fn expect_token(&mut self, expected: Token) -> Result<(), String> {
+        if self.position < self.tokens.len() && self.tokens[self.position] == expected {
+            self.position += 1;
+            Ok(())
+        } else {
+            Err(format!(
+                "Expected {:?}, found {:?}",
+                expected,
+                self.tokens.get(self.position)
+            ))
+        }
+    }
+
+    fn consume_if(&mut self, token: Token) -> bool {
+        if self.position < self.tokens.len() && self.tokens[self.position] == token {
+            self.position += 1;
+            true
+        } else {
+            false
+        }
+    }
+}
+
+struct Interpreter {
+    variables: HashMap<String, String>,
+    functions: HashMap<String, ASTNode>,
+    background_jobs: Arc<Mutex<Vec<Child>>>,
+}
+
+impl Interpreter {
+    fn new() -> Self {
+        Interpreter {
+            variables: HashMap::new(),
+            functions: HashMap::new(),
+            background_jobs: Arc::new(Mutex::new(Vec::new())),
+        }
+    }
+
+    fn interpret(&mut self, nodes: Vec<ASTNode>) -> Result<(), String> {
+        for node in nodes {
+            self.interpret_node(Box::new(node))?;
+        }
+        Ok(())
+    }
+
+    fn interpret_node(&mut self, node: Box<ASTNode>) -> Result<Option<i32>, String> {
+        match *node {
+            ASTNode::Command { name, args } => self.execute_command(name, args),
+            ASTNode::Assignment { name, value } => {
+                self.variables.insert(name, self.expand_variables(&value));
+                Ok(None)
+            }
+            ASTNode::Pipeline(commands) => self.execute_pipeline(commands),
+            ASTNode::Redirect {
+                node,
+                direction,
+                target,
+            } => self.execute_redirect(*node, direction, target),
+            ASTNode::Block(statements) => {
+                for statement in statements {
+                    self.interpret_node(Box::new(statement))?;
+                }
+                Ok(None)
+            }
+            ASTNode::If {
+                condition,
+                then_block,
+                else_block,
+            } => {
+                if self.interpret_node(Box::new(*condition))? == Some(0) {
+                    self.interpret_node(Box::new(*then_block))
+                } else if let Some(else_block) = else_block {
+                    self.interpret_node(Box::new(*else_block))
+                } else {
+                    Ok(None)
+                }
+            }
+            ASTNode::While { condition, block } => {
+                while self.interpret_node(Box::new(*condition.clone()))? == Some(0) {
+                    self.interpret_node(Box::new(*block.clone()))?;
+                }
+                Ok(None)
+            }
+            ASTNode::For { var, list, block } => {
+                for item in list {
+                    self.variables.insert(var.clone(), item);
+                    self.interpret_node(Box::new(*block.clone()))?;
+                }
+                Ok(None)
+            }
+            ASTNode::Function { name, body } => {
+                self.functions.insert(name, *body);
+                Ok(None)
+            }
+            ASTNode::Background(node) => {
+                let bg_jobs = Arc::clone(&self.background_jobs);
+                thread::spawn(move || {
+                    let mut interpreter = Interpreter::new();
+                    interpreter.background_jobs = bg_jobs;
+                    if let Err(e) = interpreter.interpret_node(node) {
+                        eprintln!("Background job error: {}", e);
+                    }
+                });
+                Ok(None)
+            }
+        }
+    }
+
+    fn execute_command(&mut self, name: String, args: Vec<String>) -> Result<Option<i32>, String> {
+        let expanded_args: Vec<String> =
+            args.iter().map(|arg| self.expand_variables(arg)).collect();
+        match name.as_str() {
+            "echo" => {
+                println!("{}", expanded_args.join(" "));
+                Ok(Some(0))
+            }
+            "cd" => {
+                let path = if expanded_args.is_empty() {
+                    env::var("HOME").unwrap_or_else(|_| ".".to_string())
+                } else {
+                    expanded_args[0].clone()
+                };
+                if let Err(e) = env::set_current_dir(&path) {
+                    Err(format!("cd: {}", e))
+                } else {
+                    Ok(Some(0))
+                }
+            }
+            "exit" => std::process::exit(0),
+            "export" => {
+                for arg in expanded_args {
+                    let parts: Vec<&str> = arg.splitn(2, '=').collect();
+                    if parts.len() == 2 {
+                        env::set_var(parts[0], parts[1]);
+                    }
+                }
+                Ok(Some(0))
+            }
+            "jobs" => {
+                let jobs = self.background_jobs.lock().unwrap();
+                for (i, _) in jobs.iter().enumerate() {
+                    println!("[{}] Running", i + 1);
+                }
+                Ok(Some(0))
+            }
+            _ => {
+                if let Some(func) = self.functions.get(&name) {
+                    return self.interpret_node(Box::new(func.clone()));
+                }
+                let expanded_name = self.expand_variables(&name);
+                match Command::new(&expanded_name).args(&expanded_args).spawn() {
+                    Ok(mut child) => {
+                        let status = child.wait().map_err(|e| e.to_string())?;
+                        Ok(Some(status.code().unwrap_or(0)))
+                    }
+                    Err(e) => Err(format!("Failed to execute command: {}", e)),
+                }
+            }
+        }
+    }
+
+    fn execute_pipeline(&mut self, commands: Vec<ASTNode>) -> Result<Option<i32>, String> {
+        let mut previous_stdout = None;
+        let mut processes = Vec::new();
+
+        for (i, command) in commands.iter().enumerate() {
+            match command {
+                ASTNode::Command { name, args } => {
+                    let mut cmd = Command::new(self.expand_variables(name));
+                    for arg in args {
+                        cmd.arg(self.expand_variables(arg));
+                    }
+
+                    if let Some(prev_stdout) = previous_stdout.take() {
+                        cmd.stdin(prev_stdout);
+                    }
+
+                    if i < commands.len() - 1 {
+                        cmd.stdout(Stdio::piped());
+                    }
+
+                    let mut child = cmd.spawn().map_err(|e| e.to_string())?;
+                    if i < commands.len() - 1 {
+                        previous_stdout = child.stdout.take();
+                    }
+                    processes.push(child);
+                }
+                _ => return Err("Pipeline can only contain commands".to_string()),
+            }
+        }
+
+        let mut last_status = None;
+        for mut process in processes {
+            let status = process.wait().map_err(|e| e.to_string())?;
+            last_status = Some(status.code().unwrap_or(0));
+        }
+
+        Ok(last_status)
+    }
+
+    fn execute_redirect(
+        &mut self,
+        node: ASTNode,
+        direction: String,
+        target: String,
+    ) -> Result<Option<i32>, String> {
+        let target = self.expand_variables(&target);
+        match direction.as_str() {
+            ">" => {
+                let mut file = File::create(&target).map_err(|e| e.to_string())?;
+                let result = self.capture_output(Box::new(node))?;
+                file.write_all(result.as_bytes())
+                    .map_err(|e| e.to_string())?;
+                print!("{}", result);
+                Ok(Some(0))
+            }
+            "<" => {
+                let mut file = File::open(&target).map_err(|e| e.to_string())?;
+                let mut input = String::new();
+                file.read_to_string(&mut input).map_err(|e| e.to_string())?;
+                self.execute_with_input(Box::new(node), input)
+            }
+            _ => Err(format!("Unsupported redirection: {}", direction)),
+        }
+    }
+
+    fn capture_output(&mut self, node: Box<ASTNode>) -> Result<String, String> {
+        let old_stdout = io::stdout();
+        let mut handle = old_stdout.lock();
+        let mut buffer = Vec::new();
+        {
+            let mut cursor = io::Cursor::new(&mut buffer);
+            let result = self.interpret_node(node)?;
+            write!(cursor, "{:?}", result).map_err(|e| e.to_string())?;
+        }
+        handle.write_all(&buffer).map_err(|e| e.to_string())?;
+        String::from_utf8(buffer).map_err(|e| e.to_string())
+    }
+
+    fn execute_with_input(
+        &mut self,
+        node: Box<ASTNode>,
+        input: String,
+    ) -> Result<Option<i32>, String> {
+        // Create a temporary file to store the input
+        let mut temp_file = tempfile::NamedTempFile::new().map_err(|e| e.to_string())?;
+        temp_file
+            .write_all(input.as_bytes())
+            .map_err(|e| e.to_string())?;
+        temp_file.flush().map_err(|e| e.to_string())?;
+
+        // Reopen the temp file as read-only
+        let input_file = File::open(temp_file.path()).map_err(|e| e.to_string())?;
+
+        // Replace stdin with our temp file
+        let stdin = io::stdin();
+        let old_stdin = stdin.lock();
+        let new_stdin = unsafe {
+            use std::os::unix::io::FromRawFd;
+            std::fs::File::from_raw_fd(input_file.as_raw_fd())
+        };
+
+        // Execute the node with the new stdin
+        let result = self.interpret_node(node);
+
+        // Restore the old stdin
+        drop(new_stdin);
+        drop(old_stdin);
+
+        result
+    }
+
+    fn expand_variables(&self, input: &str) -> String {
+        let mut result = String::new();
+        let mut chars = input.chars().peekable();
+        while let Some(c) = chars.next() {
+            if c == '$' && chars.peek().map_or(false, |&next| next != ' ') {
+                let var_name: String = chars
+                    .by_ref()
+                    .take_while(|&c| c.is_alphanumeric() || c == '_')
+                    .collect();
+                if var_name == "*" || var_name == "@" {
+                    // Expand to all arguments
+                    result.push_str(&env::args().skip(1).collect::<Vec<String>>().join(" "));
+                } else if let Ok(value) = env::var(&var_name) {
+                    result.push_str(&value);
+                } else if let Some(value) = self.variables.get(&var_name) {
+                    result.push_str(value);
+                }
+            } else if c == '~' && (chars.peek().is_none() || chars.peek() == Some(&'/')) {
+                if let Ok(home) = env::var("HOME") {
+                    result.push_str(&home);
+                } else {
+                    result.push(c);
+                }
+            } else {
+                result.push(c);
+            }
+        }
+        result
+    }
+
+    fn expand_wildcards(&self, pattern: &str) -> Vec<String> {
+        match glob(pattern) {
+            Ok(paths) => paths
+                .filter_map(Result::ok)
+                .map(|path| path.to_string_lossy().into_owned())
+                .collect(),
+            Err(_) => vec![pattern.to_string()],
+        }
+    }
+}
+
+fn main() -> Result<(), String> {
+    let mut interpreter = Interpreter::new();
+
+    let args: Vec<String> = env::args().collect();
+    if args.len() > 1 {
+        // Execute script file
+        let filename = &args[1];
+        let content = fs::read_to_string(filename)
+            .map_err(|e| format!("Error reading file {}: {}", filename, e))?;
+        let lexer = Lexer::new(content);
+        let tokens: Vec<Token> = lexer.into_iter().collect();
+        let mut parser = Parser::new(tokens);
+        let ast = parser.parse()?;
+        interpreter.interpret(ast)?;
+    } else {
+        // Interactive mode
+        loop {
+            print!("bellos> ");
+            io::stdout().flush().unwrap();
+
+            let mut input = String::new();
+            io::stdin().read_line(&mut input).unwrap();
+
+            if input.trim().is_empty() {
+                continue;
+            }
+
+            let lexer = Lexer::new(input);
+            let tokens: Vec<Token> = lexer.into_iter().collect();
+            let mut parser = Parser::new(tokens);
+            match parser.parse() {
+                Ok(ast) => {
+                    if let Err(e) = interpreter.interpret(ast) {
+                        eprintln!("Error: {}", e);
+                    }
+                }
+                Err(e) => eprintln!("Parse error: {}", e),
+            }
+        }
+    }
+    Ok(())
+}
+
+impl Iterator for Lexer {
+    type Item = Token;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        self.next_token()
+    }
+}