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99 lines
3.2 KiB
Plaintext
99 lines
3.2 KiB
Plaintext
.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved
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.TH "SETREUID" 3P 2003 "IEEE/The Open Group" "POSIX Programmer's Manual"
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.\" setreuid
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.SH PROLOG
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This manual page is part of the POSIX Programmer's Manual.
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The Linux implementation of this interface may differ (consult
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the corresponding Linux manual page for details of Linux behavior),
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or the interface may not be implemented on Linux.
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.SH NAME
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setreuid \- set real and effective user IDs
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.SH SYNOPSIS
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.LP
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\fB#include <unistd.h>
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.br
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.sp
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int setreuid(uid_t\fP \fIruid\fP\fB, uid_t\fP \fIeuid\fP\fB); \fP
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\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 \fIsetreuid\fP() function shall set the real and effective user
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IDs of the current process to the values specified by the
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\fIruid\fP and \fIeuid\fP arguments. If \fIruid\fP or \fIeuid\fP is
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-1, the corresponding effective or real user ID of the
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current process shall be left unchanged.
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.LP
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A process with appropriate privileges can set either ID to any value.
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An unprivileged process can only set the effective user ID
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if the \fIeuid\fP argument is equal to either the real, effective,
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or saved user ID of the process.
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.LP
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It is unspecified whether a process without appropriate privileges
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is permitted to change the real user ID to match the current
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real, effective, or saved set-user-ID of the process.
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.SH RETURN VALUE
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.LP
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Upon successful completion, 0 shall be returned. Otherwise, -1 shall
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be returned and \fIerrno\fP set to indicate the error.
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.SH ERRORS
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.LP
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The \fIsetreuid\fP() function shall fail if:
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.TP 7
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.B EINVAL
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The value of the \fIruid\fP or \fIeuid\fP argument is invalid or out-of-range.
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.TP 7
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.B EPERM
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The current process does not have appropriate privileges, and either
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an attempt was made to change the effective user ID to a
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value other than the real user ID or the saved set-user-ID or an attempt
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was made to change the real user ID to a value not
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permitted by the implementation.
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.sp
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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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.SS Setting the Effective User ID to the Real User ID
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.LP
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The following example sets the effective user ID of the calling process
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to the real user ID, so that files created later will be
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owned by the current user.
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.sp
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.RS
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.nf
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\fB#include <unistd.h>
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#include <sys/types.h>
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\&...
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setreuid(getuid(), getuid());
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\&...
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\fP
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.fi
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.RE
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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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None.
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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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\fIgetegid\fP(), \fIgeteuid\fP(), \fIgetgid\fP(), \fIgetuid\fP(),
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\fIsetegid\fP(), \fIseteuid\fP(), \fIsetgid\fP(), \fIsetregid\fP(),
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\fIsetuid\fP(), the Base Definitions volume of
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IEEE\ Std\ 1003.1-2001, \fI<unistd.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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