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PROLOG | NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | EXAMPLES | APPLICATION USAGE | RATIONALE | FUTURE DIRECTIONS | SEE ALSO | COPYRIGHT |
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UMASK(3P) POSIX Programmer's Manual UMASK(3P)
This manual page is part of the POSIX Programmer's Manual. The
Linux implementation of this interface may differ (consult the
corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
umask — set and get the file mode creation mask
#include <sys/stat.h>
mode_t umask(mode_t cmask);
The umask() function shall set the file mode creation mask of the
process to cmask and return the previous value of the mask. Only
the file permission bits of cmask (see <sys/stat.h>) are used;
the meaning of the other bits is implementation-defined.
The file mode creation mask of the process is used to turn off
permission bits in the mode argument supplied during calls to the
following functions:
* open(), openat(), creat(), mkdir(), mkdirat(), mkfifo(), and
mkfifoat()
* mknod(), mknodat()
* mq_open()
* sem_open()
Bit positions that are set in cmask are cleared in the mode of
the created file.
The file permission bits in the value returned by umask() shall
be the previous value of the file mode creation mask. The state
of any other bits in that value is unspecified, except that a
subsequent call to umask() with the returned value as cmask shall
leave the state of the mask the same as its state before the
first call, including any unspecified use of those bits.
No errors are defined.
The following sections are informative.
None.
None.
Unsigned argument and return types for umask() were proposed. The
return type and the argument were both changed to mode_t.
Historical implementations have made use of additional bits in
cmask for their implementation-defined purposes. The addition of
the text that the meaning of other bits of the field is
implementation-defined permits these implementations to conform
to this volume of POSIX.1‐2017.
None.
creat(3p), exec(1p), mkdir(3p), mkfifo(3p), mknod(3p),
mq_open(3p), open(3p), sem_open(3p)
The Base Definitions volume of POSIX.1‐2017, sys_stat.h(0p),
sys_types.h(0p)
Portions of this text are reprinted and reproduced in electronic
form from IEEE Std 1003.1-2017, Standard for Information
Technology -- Portable Operating System Interface (POSIX), The
Open Group Base Specifications Issue 7, 2018 Edition, Copyright
(C) 2018 by the Institute of Electrical and Electronics
Engineers, Inc and The Open Group. In the event of any
discrepancy between this version and the original IEEE and The
Open Group Standard, the original IEEE and The Open Group
Standard is the referee document. The original Standard can be
obtained online at http://www.opengroup.org/unix/online.html .
Any typographical or formatting errors that appear in this page
are most likely to have been introduced during the conversion of
the source files to man page format. To report such errors, see
https://www.kernel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group 2017 UMASK(3P)
Pages that refer to this page: sys_stat.h(0p), mkdir(1p), sh(1p), umask(1p), exec(3p), mkdir(3p), mkfifo(3p), mknod(3p), open(3p), posix_typed_mem_open(3p), shm_open(3p)
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HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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