external function.

• open, close, read, write, malloc, free, perror, strerror, access, dup, dup2, execve, exit, fork, pipe, unlink, wait, waitpid
• ft_printf and any equivalent YOU coded (libft, printf, gnl ,, )

open, close, read, write, malloc, free

• open

perror, strerror, access

• perror
• strerror
• access

dup, dup2

• dup for minishell
• dup for minishell
• dup for minishell
• dup2 for minishell