umask(2) BSD System Calls Manual umask(2)
umask -- set file creation mode mask
#include <sys/stat.h> mode_t umask(mode_t cmask);
The umask() routine sets the process's file mode creation mask to cmask and returns the previous value of the mask. The 9 low-order access per- mission bits of cmask are used by system calls, including open(2), mkdir(2), mkfifo(2), and mknod(2) to turn off corresponding bits requested in file mode. (See chmod(2)). This clearing allows each user to restrict the default access to his files. The default mask value is S_IWGRP | S_IWOTH (022, write access for the owner only). Child processes inherit the mask of the calling process.
The previous value of the file mode mask is returned by the call.
The umask() function is always successful.
#include <sys/types.h> #include <sys/stat.h> The include file <sys/types.h> is necessary.
The umask() function call is expected to conform to IEEE Std 1003.1-1988 (``POSIX.1''). 4th Berkeley Distribution June 4, 1993 4th Berkeley Distribution
Mac OS X 10.9.1 - Generated Mon Jan 6 18:34:41 CST 2014