https://github.com/dcavalei/exam-rank-04-microshell

My code for microshell exam
https://github.com/dcavalei/exam-rank-04-microshell

42 42born2code 42lisboa c microshell

Last synced: 14 days ago
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My code for microshell exam

• Host: GitHub
• URL: https://github.com/dcavalei/exam-rank-04-microshell
• Owner: dcavalei
• Created: 2022-01-21T15:34:25.000Z (almost 3 years ago)
• Default Branch: main
• Last Pushed: 2022-01-21T15:47:39.000Z (almost 3 years ago)
• Last Synced: 2023-05-06T11:33:11.476Z (over 1 year ago)
• Topics: 42, 42born2code, 42lisboa, c, microshell
• Language: C
• Homepage:
• Size: 1.95 KB
• Stars: 4
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
# exam-rank-04-microshell

**Assignment name**  : microshell

**Expected files**   : *.c *.h

**Allowed functions**:

* malloc, free, write, close, fork,

* waitpid, signal, kill, exit, chdir,

* execve, dup, dup2, pipe, strcmp, strncmp

--------------------------------------------------------------------------------------

## 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.

--------------------------------------------------------------------------------------

## for example this should work:

```bash

$ ./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

Hints:

Do not leak file descriptors!