minishell

Recoding a shell in C

First non-solo project of the 42 Paris cursus, realised with Clement Dai

Code stats

• Total : 6061 lines
  • C : 4504 lines (74,3%)
  • Shell : 1557 lines (25.7%)
• Git :
  • 2 repositories (project + tests)
  • 357 commits
  • 22 branches

Goals :

• introduce us to the processes through fork, wait, kill
• gain a deeper understanding of file descriptors
• step up in termes of parsing and error handling
• understand and implement the notions of
  • parser-lexer
  • tokeniser
  • abstract syntax tree

Since it was a very demanding project in terms of edge-cases, I implemented my own tester, which helped us :

• advance in our work without breaking what was previously working
• compile future tests for future work
• get a glimpse of Test Driven Development

Features :

• Writes a prompt waiting for a new command

• Searches and launches the right executable (based on the PATH environment variable, or using a relative or absolute path)

• Builtins cmds :

  • echo
  • cd
  • pwd
  • export
  • unset
  • env
  • exit

• Handles ';', single and double quotes (except in multiline), and the use of '\'

• Redirections : '<', '>' and '>>'

• Pipes

• Environment variables

• Return values ("echo $?")

• Signals : ctrl-C, ctrl-D, ctrl-\