GETUMASK(3) Linux Programmer's Manual GETUMASK(3)NAME
getumask - get file creation mask
SYNOPSIS
#define _GNU_SOURCE /* See feature_test_macros(7) */
#include <sys/types.h>
#include <sys/stat.h>
mode_t getumask(void);
DESCRIPTION
This function returns the current file creation mask. It is equivalent to
mode_t getumask(void)
{
mode_t mask = umask( 0 );
umask(mask);
return mask;
}
except that it is documented to be thread-safe (that is, shares a lock with the umask(2) library call).
CONFORMING TO
This is a vaporware GNU extension.
NOTES
This function is documented but not implemented yet in glibc, as at version 2.9.
SEE ALSO umask(2)COLOPHON
This page is part of release 3.27 of the Linux man-pages project. A description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.
GNU 2010-09-10 GETUMASK(3)
Check Out this Related Man Page
UMASK(2) Linux Programmer's Manual UMASK(2)NAME
umask - set file mode creation mask
SYNOPSIS
#include <sys/types.h>
#include <sys/stat.h>
mode_t umask(mode_t mask);
DESCRIPTION
umask() sets the calling process's file mode creation mask (umask) to mask & 0777 (i.e., only the file permission bits of mask are used),
and returns the previous value of the mask.
The umask is used by open(2), mkdir(2), and other system calls that create files to modify the permissions placed on newly created files or
directories. Specifically, permissions in the umask are turned off from the mode argument to open(2) and mkdir(2).
The constants that should be used to specify mask are described under stat(2).
The typical default value for the process umask is S_IWGRP | S_IWOTH (octal 022). In the usual case where the mode argument to open(2) is
specified as:
S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH
(octal 0666) when creating a new file, the permissions on the resulting file will be:
S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH
(because 0666 & ~022 = 0644; i.e., rw-r--r--).
RETURN VALUE
This system call always succeeds and the previous value of the mask is returned.
CONFORMING TO
SVr4, 4.3BSD, POSIX.1-2001.
NOTES
A child process created via fork(2) inherits its parent's umask. The umask is left unchanged by execve(2).
The umask setting also affects the permissions assigned to POSIX IPC objects (mq_open(3), sem_open(3), shm_open(3)), FIFOs (mkfifo(3)), and
Unix domain sockets (unix(7)) created by the process. The umask does not affect the permissions assigned to System V IPC objects created
by the process (using msgget(2), semget(2), shmget(2)).
SEE ALSO chmod(2), mkdir(2), open(2), stat(2)COLOPHON
This page is part of release 3.25 of the Linux man-pages project. A description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.
Linux 2008-01-09 UMASK(2)