Untitled

d2

• IN PROGRESS
• TO DO
• DONE

Pauline (Kid_P)

• IN PROGRESS
• TO DO
• DONE

🌐Blueprint

This minishell should have the characteristics of a specific shell. We will use bash as a reference. Functions are written with readability, scalability, modularity and overall robustness in mind.

Main Loop

• [x] Setup infinite loop with readline(prompt)
  • [x] infinite loop must take env as argument
• [x] Handle Ctrl-D (EOF) to exit
• [x] Add input line to history (add_history)
• [x] Forward input to tokenization and AST pipeline
• [x] Provide lookup function for $VAR expansion

Import Environment Variables

• [x] Copy envp into linked
  • [x] SHLVL needs to be updated by +1 after import
• [x] Store key and value separately

Tokenize Input

• [x] Split input into char **tokens
• [x] Handle quotes correctly to group multi-word arguments
• [x] Preserve special characters for redirections/pipes

Validate Syntax - Lexer

• [x] Check for unclosed quotes
• [x] Validate pipe | positions
• [x] Check redirection operators <, >, >>, << have targets
• [x] Reject unsupported characters (\\\\, ;)
• [x] Ignore empty input lines

Expand Environment Variables

• [x] Loop through tokens
• [x] Replace $VAR with value from environment
• [x] Replace $? with last command exit status
• [x] Respect quotes: single '...' no expansion, double "..." expand
• [x] Free old token strings and malloc new ones as needed

Quote trimming

• [x] trim quotes

Setup Signal Handlers

• [x] Handle Ctrl-C (SIGINT) → new prompt
• [x] Handle Ctrl-D → exit shell
• [x] Handle Ctrl-\ (SIGQUIT) → ignore
• [x] Ensure signals behave correctly during child process execution

Implement Built-ins

• [x] Implement cd → change current directory
• [x] Implement echo → print arguments
• [x] Implement pwd → print working directory
• [x] Implement export → add/update environment variable
  • [x] Allow insertion for export if args given
  • [x] print export list if no args given
  • [x] sort export list before printing
  • [x] handle append to value KEY+=123 which appends 123 to the existing value of KEY
• [x] Implement unset → remove environment variable
• [x] Implement env → print all environment variables
• [x] Implement exit → exit shell with optional status
• [x] Create builtin[] table mapping names → function pointers

Build AST

• [x] Convert token array into AST nodes
• [x] NODE_COMMAND → store command + args
• [x] NODE_PIPE → left/right children
• [x] NODE_REDIR → operator + target file
• [x] Ensure tree correctly represents command structure

Execute AST

• [x] Traverse AST recursively
• [x] For NODE_COMMAND: check if builtin → call implemented function
• [x] If not builtin → execve() external command
• [x] execute_external_commands()
• [x] Handle pipes correctly
• [x] Handle redirections (<, >, >>, <<)
• [x] Apply signal behavior during execution

Cleanup & Loop Back

• [x] Free AST nodes
• [x] Free token arrays
• [x] Return to main loop and prompt for next input

📖 git - how to

Git conventional commits cheatsheet

Pull Request

Validating (Merging) a Pull Request

Creating a New Branch

Cherry-Pick

📚Resources

Task Rabbit

minishell error code standardization proposal

📋minishell edge cases

valgrind .supp file to ignore leaks from readline library