/minishell

As beautiful as a shell

Primary LanguageC

Introduction

This is the 8th École 42 project, and is about creating a simple shell, where we learn a lot about Shell, processes, UNIX and file descriptors, debbuging, hash tables, lexical analysis and much more.
Also this is the first e42 project that requires group work, so we learn a lot about mob programming, documentation, git tools like working on different branches and task management as well.

About the project

The project requires your Shell to:

  • 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.
  • 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. 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.
  • 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

Usage:

Install Readline library with

$ sudo apt-get install libreadline-dev

Compile the program make
You're ready to run it, have fun!! ./minishell

Developed by:

prmarquesz
GuiMartinelli