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75 lines
2.6 KiB
Plaintext
75 lines
2.6 KiB
Plaintext
.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved
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.TH "UMASK" P 2003 "IEEE/The Open Group" "POSIX Programmer's Manual"
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.\" umask
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.SH NAME
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umask \- set and get the file mode creation mask
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.SH SYNOPSIS
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.LP
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\fB#include <sys/stat.h>
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.br
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.sp
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mode_t umask(mode_t\fP \fIcmask\fP\fB);
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.br
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\fP
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.SH DESCRIPTION
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.LP
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The \fIumask\fP() function shall set the process' file mode creation
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mask to \fIcmask\fP and return the previous value of the
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mask. Only the file permission bits of \fIcmask\fP (see \fI<sys/stat.h>\fP)
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are
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used; the meaning of the other bits is implementation-defined.
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.LP
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The process' file mode creation mask is used during \fIopen\fP(),
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\fIcreat\fP(), \fImkdir\fP(), and \fImkfifo\fP() to turn off permission
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bits in the \fImode\fP argument supplied. Bit positions that
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are set in \fIcmask\fP are cleared in the mode of the created file.
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.SH RETURN VALUE
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.LP
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The file permission bits in the value returned by \fIumask\fP() shall
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be the previous value of the file mode creation mask. The
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state of any other bits in that value is unspecified, except that
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a subsequent call to \fIumask\fP() with the returned value as
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\fIcmask\fP shall leave the state of the mask the same as its state
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before the first call, including any unspecified use of those
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bits.
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.SH ERRORS
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.LP
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No errors are defined.
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.LP
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\fIThe following sections are informative.\fP
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.SH EXAMPLES
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.LP
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None.
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.SH APPLICATION USAGE
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.LP
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None.
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.SH RATIONALE
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.LP
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Unsigned argument and return types for \fIumask\fP() were proposed.
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The return type and the argument were both changed to
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\fBmode_t\fP.
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.LP
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Historical implementations have made use of additional bits in \fIcmask\fP
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for their implementation-defined purposes. The
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addition of the text that the meaning of other bits of the field is
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implementation-defined permits these implementations to conform
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to this volume of IEEE\ Std\ 1003.1-2001.
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.SH FUTURE DIRECTIONS
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.LP
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None.
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.SH SEE ALSO
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.LP
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\fIcreat\fP() , \fImkdir\fP() , \fImkfifo\fP() ,
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\fIopen\fP() , the Base Definitions volume of IEEE\ Std\ 1003.1-2001,
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\fI<sys/stat.h>\fP, \fI<sys/types.h>\fP
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.SH COPYRIGHT
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Portions of this text are reprinted and reproduced in electronic form
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from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
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-- Portable Operating System Interface (POSIX), The Open Group Base
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Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
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Electrical and Electronics Engineers, Inc and The Open Group. In the
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event of any discrepancy between this version and the original IEEE and
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The Open Group Standard, the original IEEE and The Open Group Standard
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is the referee document. The original Standard can be obtained online at
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http://www.opengroup.org/unix/online.html .
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