minishell

The Minishell project involves creating a simplified version of a Unix shell.

It requires implementing basic shell features like displaying a prompt, handling command history, and executing programs based on the PATH environment variable.

The project focuses on handling special characters, quotes, implementing redirections, pipes, and managing environment variables.

It also requires implementing a few built-in commands like echo, cd, pwd, export, unset, env, and exit.

Additionally, the project deals with signal handling, specifically for ctrl-C, ctrl-D, and ctrl-.

Features

• Prompt Display: Displays a prompt when waiting for new commands.
• Command History: Maintains a working history of commands.
• Executable Search: Searches and launches executables based on PATH or given paths.
• Global Variable Limitation: Utilizes no more than one global variable.
• Special Characters: Does not interpret unclosed quotes or non-essential special characters like \ or ;.
• Quotes Handling:
  • Single quotes ' prevent meta-character interpretation.
  • Double quotes " prevent meta-character interpretation except for $.
• Redirections:
  • <: Redirects input.
  • >: Redirects output.
  • <<: Reads input until a line containing the given delimiter.
  • >>: Redirects output in append mode.
• Pipes: Implements pipes (|) where output of one command is piped as input to the next.
• Environment Variables: Handles expansion of environment variables ($).
• Exit Status: $? expands to the exit status of the most recently executed foreground pipeline.
• Signal Handling:
  • ctrl-C: Displays a new prompt on a new line.
  • ctrl-D: Exits the shell.
  • ctrl-\: No action.
• Builtins:
  • echo with -n
  • cd with 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

Subject PDF