- Write a simple UNIX command interpreter.
- Who designed and implemented the original Unix operating system
- Who wrote the first version of the UNIX shell
- Who invented the B programming language (the direct predecessor to the C programming language)
- Who is Ken Thompson
- How does a shell work
- What is a pid and a ppid
- How to manipulate the environment of the current process
- What is the difference between a function and a system call
- How to create processes
- What are the three prototypes of main
- How does the shell use the PATH to find the programs
- How to execute another program with the execve system call
- How to suspend the execution of a process until one of its children terminates
- What is EOF / “end-of-file”?
| File | Task |
|---|---|
| builtins.c | exiteme, printenv, cd - functions |
| env.c | function to write env |
| exec.c | execute command |
| getcommand.c | functions get_line, split_line - gets input from stdin |
| getpath.c | functions get_env, dirTok, checkPath - gets PATH from environment |
| looper.c | main loop to initiate shell |
| prompt.c | print prompt |
| shell.c | main function |
| shell.h | header with libraryies and prototypes |
| stringhelpers | functions _strcmp, _strdup _strlen |
| Directory Name | Description |
|---|---|
| simple_shell | Write a simple UNIX command interpreter |
gcc 4.8.4 using the flags -Wall -Werror -Wextra and -pedantic
All files is formatted Betty style and checked using betty-style.pl and betty-doc.pl All header files is guarded
Heindrick Cheung && Damon Nyhan