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UMASK(2) | System Calls Manual | UMASK(2) |
NAME¶
umask
—
set file creation mode mask
LIBRARY¶
Standard C Library (libc, -lc)SYNOPSIS¶
#include
<sys/stat.h>
mode_t
umask
(mode_t
numask);
DESCRIPTION¶
Theumask
() routine sets the process's file
mode creation mask to numask and returns the
previous value of the mask. The 9 low-order access permission bits of
numask are used by system calls, including
open(2), mkdir(2),
and mkfifo(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.
RETURN VALUES¶
The previous value of the file mode mask is returned by the call.ERRORS¶
Theumask
() system call is always successful.
SEE ALSO¶
chmod(2), mkfifo(2), mknod(2), open(2)STANDARDS¶
Theumask
() system call is expected to
conform to IEEE Std 1003.1-1990
(“POSIX.1”).
HISTORY¶
Theumask
() function appeared in
Version 7 AT&T UNIX.June 4, 1993 | Debian |