Unix-like system calls
======================

pid_t fork(void);
Creates a child process.

void exit(int status);
Terminate the calling process.

pid_t waitpid(pid_t pid);
Wait untill a process changes state.

int kill(pid_t, int sig);
Send a signal to a process.

pid_t getpid(void);
Get PID of calling process.

void sleep(size_t t);
Sleep for **t** clock ticks.

int exec(char* path, char** argv);
Execute a program.

int brk(void* addr);
Change data segment size.

int open(char* path, int flags);
Open and possibly create a file.

int close(int fd);
Close a file descriptor.

ssize_t read(int fd, void* buf, size_t count);
Read up to **count** bytes into **buf**.

ssize_t write(int fd, void* buf, size_t count);
Write up to **count** bytes from **buf**.

int dup(int oldfd);
Duplicate a file descriptor.

int pipe(int pipe[2]);
Create a pipe and return it's file descriptors in **pipe**.

int chdir(char* path);
Change the current directory of calling process.

int mkdir(char* path);
Create a new directory.

int mknod(char* path, int maj, int min);
Create a new device file.

int link(char* f1, char* f2);
Creates another filename (**f2**) for **f1**.

int unlink(char* path);
Delete a filename.

int fstat(int fd, struct stat* statbuf);
Return info about a file.