C Programming/POSIX Reference/fcntl.h

fcntl.h is the header in the C POSIX library for the C programming language that contains constructs that refer to file control, e.g. opening a file, retrieving and changing the permissions of file, locking a file for edit, etc.

int fcntl(int __fd, int __cmd, ...)

int open(char* pathname, int flags, ...);
int creat(const char *,int);