https://github.com/loyc12/microshell42

42 Exam Project
https://github.com/loyc12/microshell42

Last synced: 8 days ago
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42 Exam Project

• Host: GitHub
• URL: https://github.com/loyc12/microshell42
• Owner: loyc12
• Created: 2023-06-19T17:55:58.000Z (over 1 year ago)
• Default Branch: master
• Last Pushed: 2024-08-13T16:57:08.000Z (3 months ago)
• Last Synced: 2024-08-13T20:13:22.826Z (3 months ago)
• Language: C
• Size: 5.86 KB
• Stars: 0
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
# Exam Question

This exam has 1 question, microshell:

- [Microshell.c](https://github.com/pasqualerossi/42-School-Exam-Rank-04/blob/main/microshell.c)

- [Microshell.h](https://github.com/pasqualerossi/42-School-Exam-Rank-04/blob/main/microshell.h)

if you can make this code shorter, whilst still readable, let me know!




## Expected Files

- microshell.c

- microshell.h

## Subject Text

Allowed functions:

```

malloc, free, write, close, fork, waitpid, signal, kill, exit, chdir, execve, dup, dup2, pipe, strcmp, strncmp

```

## The Program

Write a program that will behave like executing a shell command

- The command line to execute will be the arguments of this program

- Executable's path will be absolute or relative but your program must not build a path (from the PATH variable for example)

- You must implement "|" and ";" like in bash

	- we will never try a "|" immediately followed or preceded by nothing or "|" or ";"

- Your program must implement the built-in command cd only with a path as argument (no '-' or without parameters)

	- if cd has the wrong number of argument your program should print in STDERR "error: cd: bad arguments" followed by a '\n'

	- if cd failed your program should print in STDERR "error: cd: cannot change directory to path_to_change" followed by a '\n' with path_to_change replaced by the argument to cd

	- a cd command will never be immediately followed or preceded by a "|"

- You don't need to manage any type of wildcards (*, ~ etc...)

- You don't need to manage environment variables ($BLA ...)

- If a system call, except execve and chdir, returns an error your program should immediatly print "error: fatal" in STDERR followed by a '\n' and the program should exit

- If execve failed you should print "error: cannot execute executable_that_failed" in STDERR followed by a '\n' with executable_that_failed replaced with the path of the failed executable (It should be the first argument of execve)

- Your program should be able to manage more than hundreds of "|" even if we limit the number of "open files" to less than 30.

## Example

for example this should work:

```

$>./microshell /bin/ls "|" /usr/bin/grep microshell ";" /bin/echo i love my microshell

microshell

i love my microshell

$>

```

## Hints

- Don't forget to pass the environment variable to execve

- Do not leak file descriptors!

## Exam Practice

Practice the exam just like you would in the real exam - https://github.com/JCluzet/42_EXAM