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umask(3p) — Linux manual page

PROLOG \|NAME \|SYNOPSIS \|DESCRIPTION \|RETURN VALUE \|ERRORS \|EXAMPLES \|APPLICATION USAGE \|RATIONALE \|FUTURE DIRECTIONS \|SEE ALSO \|COPYRIGHT

UMASK(3P)               POSIX Programmer's ManualUMASK(3P)

PROLOG top

       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.

NAME top

       umask — set and get the file mode creation mask

SYNOPSIS top

       #include <sys/stat.h>       mode_t umask(mode_tcmask);

DESCRIPTION top

       Theumask() function shall set the file mode creation mask of the       process tocmask and return the previous value of the mask. Only       the file permission bits ofcmask (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 themode argument supplied during calls to the       following functions:        *open(),openat(),creat(),mkdir(),mkdirat(),mkfifo(), andmkfifoat()        *mknod(),mknodat()        *mq_open()        *sem_open()       Bit positions that are set incmask are cleared in the mode of the       created file.

RETURN VALUE top

       The file permission bits in the value returned byumask() 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 toumask() with the returned value ascmask shall       leave the state of the mask the same as its state before the first       call, including any unspecified use of those bits.

ERRORS top

       No errors are defined.The following sections are informative.

EXAMPLES top

       None.

APPLICATION USAGE top

       None.

RATIONALE top

       Unsigned argument and return types forumask() were proposed. The       return type and the argument were both changed tomode_t.       Historical implementations have made use of additional bits incmask 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.

FUTURE DIRECTIONS top

       None.

COPYRIGHT top

       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 athttp://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, seehttps://www.kernel.org/doc/man-pages/reporting_bugs.html .IEEE/The Open Group                2017UMASK(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)