umask(2)

NAME
     umask - set file creation mode mask

SYNOPSIS
     #include <sys/types.h>
     #include <sys/stat.h>

     mode_t umask(mode_t mask)

DESCRIPTION
     Umask sets the process's file mode creation mask to mask and returns  the
     previous  value  of  the  mask.   The  low-order  9 bits of mask are used
     whenever a file is created, clearing corresponding bits in the file  mode
     (see  chmod(2)).   This clearing allows each user to restrict the default
     access to his files.

     The value is initially 022 (write access for owner only).   The  mask  is
     inherited by child processes.

RETURN VALUE
     The previous value of the file mode mask is returned by the call.

SEE ALSO
     chmod(2), mknod(2), open(2).