Minishell_Team

Mandatory part

Your shell should:

• Display a prompt when waiting for a new command.
• Have a working history.
• Search and launch the right executable (based on the PATH variable or using a relative or an absolute path).
• Not use more than one global variable. Think about it. You will have to explain its purpose.
• Not interpret unclosed quotes or special characters which are not required by the subject such as \ (backslash) or ; (semicolon).
• Handle ’ (single quote) which should prevent the shell from interpreting the metacharacters in the quoted sequence.
• Handle " (double quote) which should prevent the shell from interpreting the metacharacters in the quoted sequence except for $ (dollar sign).
• Implement redirections:
  • < should redirect input.

  • should redirect output.

  • << should be given a delimiter, then read the input until a line containing the
• delimiter is seen. However, it doesn’t have to update the history!

  • should redirect output in append mode.

• Implement pipes (| character). The output of each command in the pipeline is connected to the input of the next command via a pipe.
• Handle environment variables ($ followed by a sequence of characters) which should expand to their values.
• Handle $? which should expand to the exit status of the most recently executed foreground pipeline.
• Handle ctrl-C, ctrl-D and ctrl-\ which should behave like in bash.
• In interactive mode:
  • ctrl-C displays a new prompt on a new line.
  • ctrl-D exits the shell.
  • ctrl-\ does nothing.
• Your shell must implement the following builtins:
  • echo with option -n
  • cd with only a 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
• The readline() function can cause memory leaks. You don’t have to fix them. But that doesn’t mean your own code, yes the code you wrote, can have memory leaks.

Resources

• https://www.ibm.com/docs/en/rdfi/9.6.0?topic=errors-checking-errno-value
• https://github.com/simon-ameye/42-minishell_bash_tester_2022
• https://www.ibm.com/docs/en/rdfi/9.6.0?topic=errors-checking-errno-value
• https://medium.com/swlh/understanding-pipes-in-unix-with-a-sample-implementation-9fe110d36412
• https://gist.github.com/zed/7835043