установить и получить маску создания режима файла (set and get the file mode creation mask)
Пролог (Prolog)
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.
Имя (Name)
umask — set and get the file mode creation mask
Синопсис (Synopsis)
#include <sys/stat.h>
mode_t umask(mode_t cmask);
Описание (Description)
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.
Возвращаемое значение (Return value)
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.
Ошибки (Error)
No errors are defined.
The following sections are informative.
Примеры (Examples)
None.
Использование в приложениях (Application usage)
None.
Обоснование (Rationale)
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.
Будущие направления (Future directions)
None.
Смотри также (See also)
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)
