21sh-42sh

Introduction

21sh-42sh is a Linux CLI (Command Line Interface) thought, designed, and made by chbravo-, gpouyat, jlasne and mleroy for the school 42 as the last project before their first internship.

Final grade for 21sh: 100

Final grade for 42sh: 74

Installation | Compilation

To compile 21sh-42sh, first clone the project with the submodules (git clone https://github.com/cbcercas/21sh-42sh.git --recursive --branch master to clone the branch master for example). Once cloned and moved into the directory, type make. 21-42sh auto-configures the build process, so no further intervention should be necessary. 21-42sh builds with clang by default if it is available. If you want to use gcc instead, type make CC=gcc

The DEV and SAN flags are avaibles if you want to enable -g or fsanetize

Reporting bugs

Bug reports for 21sh-42sh should be reported in the issues section on our Github page along with:

• the version number (if available, else the commit used by the last build)
• the machine and OS that it is running on
• a list of the compilation flags
• a list of the flags passed to the shell
• a description of the bug
• a recipe for recreating the bug reliably
• a fix for the bug if you have one!

Features

• Line editing

  • Simple and advanced line editing
  • Edit the line where the cursor is positionned
  • Move cursor left or right
  • Up and Down arrows to navigate in the history
  • Enter Insert mode with alt+i and exit it with alt+i
  • Copy and paste with alt+C alt+v
  • Move word per word left or right alt+LEFT alt+RIGHT
  • Go to beginning or end of a line. home end
  • Move to top or bottom line. alt+UP alt+DOWN
  • Waits for the end of a quote or double quote.
  • ctrl+D and ctrl+C usable when editing a line or in multi-line.
  • Multiline line editing

• Builtins with their POSIX options (For more info type help once in the shell)

  • cd | chdir
  • echo
  • exit
  • env
  • setenv
  • unsetenv
  • unset
  • export
  • history
  • pwd

• Exec

  • Executing commands stored in path with their parameters
  • Error handling and return value handling
  • Smiley face based on return value from previous command (^_^ or X_X)
  • Redirections handled : >, <, << and >>
  • Pipes |
  • Logical operators && and ||
  • Backquotes "‘" (TODO)
  • Ihibitors """ (double quote), "’" (simple quote) et "" (backslash).
  • ;
  • \n handling where \n can be used as a ;. Example: ls \n ls == ls ; ls

• Prompt

  • Multi line editing with \, ' and "
  • History handles the multi-line editing

• Shell

  • This shell proposes multiple options to enhance user experience
  • h This option will display help for all options as described here
  • v Verbose mode
  • d Debug mode (Enables the logger). A log file will be created where the binary exists. This option requires a log level from 0 to 7
  • t Test mode. This mode will test the module X with Y parameter as follows : -t X Y. Can be used with modules env ast parser lexer ast
  • c Command. Use this option to send a command to the shell and get it's output
  • C Color. Use this option to enable color in the shell
  • l Disables the termcaps. This is a debug option and not a feature ! To be used lightly

• Signals

  • We kill all childs when we get a signal that kills the program so no zombie process is left behind

• Autocompletion

  • Dynamic autocompletion
  • Autocompletes binaries from PATH
  • Autocompletes files and paths
  • Autorefreshing with a new input from the user: modification of the list of possibility. TODO WIP
  • Known bug: Autocompletion displays the full path (see #124)
  • Known bug: Autocompletion doesnt expand ~ or $.

• Environ

  • Local Variables are available
  • Normal environment is used when the shell is started
  • Uses the = syntax (VAR=VALUE)
  • Default env is given when 21sh-42sh is started with env -i (TODO to be customized)
  • Message to warn the User when 21sh-42sh is started without an env

• Bonuses

  • Heredocs "<<".
  • File descriptors aggregation

• Structure

  • Init
  • Input
  • Lexer
  • Parser
  • Expand
  • Ast
  • Execution

• History

  • A menu is printed when the history fil is to big
  • The history is printed in the log when exiting the program
  • History research ctrl+R.

• Tests: 21sh-42sh contains automated tests found in the tests/ folder (See here)

  • Tests for the lexer
  • Tests for the parser
  • Tests for the ast
  • Tests for the expand
  • Tests for the exec
  • Tests for the builtins
  • Tests for the env
  • Tests for the local vars

• Miscellaneous

  • Logger
  • Doc

The output of cloc (Count Lines Of Code) as of 21/12/2017 22h30:

        465 text files.
        449 unique files.
         48 files ignored.
   
   http://cloc.sourceforge.net v 1.60  T=15.82 s (26.4 files/s, 1756.4 lines/s)
   --------------------------------------------------------------------------------
   Language                      files          blank        comment           code
   --------------------------------------------------------------------------------
   C                               321           2005           6128          12895
   C/C++ Header                     63            713           2244           1644
   Bourne Shell                     25            161             80            794
   make                              3            132            111            374
   CMake                             3             38              5            336
   Bourne Again Shell                1             16              4             61
   YAML                              1             10              0             33
   --------------------------------------------------------------------------------
   SUM:                            417           3075           8572          16137
   --------------------------------------------------------------------------------