1UMASK(P)                   POSIX Programmer's Manual                  UMASK(P)
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NAME

6       umask - set and get the file mode creation mask
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SYNOPSIS

9       #include <sys/stat.h>
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11       mode_t umask(mode_t cmask);
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DESCRIPTION

15       The  umask() function shall set the process' file mode creation mask to
16       cmask and return the previous value of the mask. Only the file  permis‐
17       sion  bits  of  cmask  (see  <sys/stat.h>) are used; the meaning of the
18       other bits is implementation-defined.
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20       The process' file mode creation mask is used  during  open(),  creat(),
21       mkdir(),  and mkfifo() to turn off permission bits in the mode argument
22       supplied. Bit positions that are set in cmask are cleared in  the  mode
23       of the created file.
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RETURN VALUE

26       The  file permission bits in the value returned by umask() shall be the
27       previous value of the file mode creation mask. The state of  any  other
28       bits  in  that  value  is unspecified, except that a subsequent call to
29       umask() with the returned value as cmask shall leave the state  of  the
30       mask the same as its state before the first call, including any unspec‐
31       ified use of those bits.
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ERRORS

34       No errors are defined.
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36       The following sections are informative.
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EXAMPLES

39       None.
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APPLICATION USAGE

42       None.
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RATIONALE

45       Unsigned argument and return types  for  umask()  were  proposed.   The
46       return type and the argument were both changed to mode_t.
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48       Historical  implementations  have  made use of additional bits in cmask
49       for their implementation-defined purposes. The  addition  of  the  text
50       that  the  meaning of other bits of the field is implementation-defined
51       permits  these  implementations  to   conform   to   this   volume   of
52       IEEE Std 1003.1-2001.
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FUTURE DIRECTIONS

55       None.
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SEE ALSO

58       creat()  , mkdir() , mkfifo() , open() , the Base Definitions volume of
59       IEEE Std 1003.1-2001, <sys/stat.h>, <sys/types.h>
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62       Portions of this text are reprinted and reproduced in  electronic  form
63       from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
64       -- Portable Operating System Interface (POSIX),  The  Open  Group  Base
65       Specifications  Issue  6,  Copyright  (C) 2001-2003 by the Institute of
66       Electrical and Electronics Engineers, Inc and The Open  Group.  In  the
67       event of any discrepancy between this version and the original IEEE and
68       The Open Group Standard, the original IEEE and The Open Group  Standard
69       is  the  referee document. The original Standard can be obtained online
70       at http://www.opengroup.org/unix/online.html .
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74IEEE/The Open Group                  2003                             UMASK(P)
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