This shell was coded by Helvi Lainekallio (hlaineka) as a part of Hive Helsinki studies. Code and subject of the project can be found on https://github.com/hlaineka/minishell. Only allowed readymade functions in this project are listed below. Everything else coded by me, including my own printf, ls-command and c-library.
Allowed readymade functions in this project:
- malloc, free
- access
- open, close, read, write
- opendir, readdir, closedir
- getcwd, chdir
- stat, lstat, fstat
- fork, execve
- wait, waitpid, wait3, wait4
- signal, kill
- exit
Mandatory requirements of the project:
- You must program a miniUNIXcommand interpreter.
- This interpreter must display a prompt (a simple "$>" for example) and
wait tillyou type a command line, validated by pressing enter.
- The prompt is shown again only once the command has been completely
executed.
- The command lines are simple, no pipes, no redirections or any other
advanced functions.
- The executable are those you can find in the paths indicated in the
PATH variable.
- In cases where the executable cannot be found, it has to show an error
message anddisplay the prompt again.
- You must manage the errors without using errno, by displaying a message
adaptedto the error output.
- You must deal correctly with the PATH and the environment (copy of
systemchar**environ).
- You must implement a series of builtins: echo,cd,setenv,unsetenv,env,exit.
- You can choose as a reference whatever shell you prefer.
- You must manage expansions $ and ̃
Additional features:
- Structure of the program has been planned so that it is scalable to future
projects of 21sh and 42sh
- Editing the text, deleting and adding in the end of your input as well as
in the middle
- Arrow keys up, left and right
- Command history behind arrow up
- Handling of quotes, also if quote is left open
- Error message printing
Add on features:
- ~ (tilde) with / + - behind it
- $ expansion working
- echo [-n]... [STRING]...
- cd [dir] also works with no dir and - Handles relative and absolute paths.
Checks the path for any errors, error handling written by hand with lstat(),
stat() and access(). Handles . and ..
- setenv [VAR] [word]
- unsetenv [var]
- env [-i] [u name] [name=value ...] [utility [arg ...]]
handles parameter -i and -u. name value pairs can be given as an argument.
Creates a temporary envp and start the utility with that envp.
- exit can be given a value manually that the shell returns at exit.
- all error are handled manually and error messages printed to the fd2
The structure of the program is shown in the activity diagram below:
