umask(2) System Calls Manual umask(2)
Name
umask - set file creation mask
Syntax
#include <sys/types.h>
#include <sys/stat.h>
oumask = umask(numask)
mode_t oumask, numask;
Description
The system call sets the process's file mode creation mask to and returns the previous value of the mask. The low-order nine bits of are
used whenever a file is created, clearing corresponding bits in the file mode. (For further information, see This clearing allows each
user to restrict the default access to his or her files.
The value is initially 022 (write access for owner only). The mask is inherited by child processes.
The previous value of the file mode mask is returned by the call.
Environment
POSIX
When your program is compiled in POSIX mode, the numask argument is of type mode_t and the function returns a value of type mode_t.
See Also
chmod(2), mknod(2), open(2)
umask(2)
