# include <readline>

• readline, rl_clear_history, rl_on_new_line, rl_replace_line, rl_redisplay, add_history

# include <fcntl.h>

• open, close

#include <unistd.h>

• read, write, access, dup, dup2, execve, fork, pipe, unlink, getcwd, isatty, ttyslot, ttyname

#include <stdlib.h>

• malloc, free, exit, getenv

# include <sys/wait.h>

• wait, waitpid, wait3, wait4

# include <signal.h>

• signal, sigaction, sigemptyset, sigaddset, kill

# include <direct.h>

• chdir

# include <sys/stat.h>

• stat, lstat, fstat

# include <dirent.h>

• opendir, readdir, closedir

#include <string.h>

• strerror