mirror of https://github.com/mkerrisk/man-pages
141 lines
3.9 KiB
Plaintext
141 lines
3.9 KiB
Plaintext
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.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved
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.TH "LCHOWN" P 2003 "IEEE/The Open Group" "POSIX Programmer's Manual"
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.\" lchown
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.SH NAME
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lchown \- change the owner and group of a symbolic link
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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 lchown(const char *\fP\fIpath\fP\fB, uid_t\fP \fIowner\fP\fB,
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gid_t\fP \fIgroup\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 \fIlchown\fP() function shall be equivalent to \fIchown\fP(),
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except in the case
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where the named file is a symbolic link. In this case, \fIlchown\fP()
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shall change the ownership of the symbolic link file itself,
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while \fIchown\fP() changes the ownership of the file or directory
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to which the symbolic
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link refers.
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.SH RETURN VALUE
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.LP
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Upon successful completion, \fIlchown\fP() shall return 0. Otherwise,
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it shall return -1 and set \fIerrno\fP to indicate an
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error.
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.SH ERRORS
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.LP
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The \fIlchown\fP() function shall fail if:
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.TP 7
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.B EACCES
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Search permission is denied on a component of the path prefix of \fIpath\fP.
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.TP 7
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.B EINVAL
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The owner or group ID is not a value supported by the implementation.
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.TP 7
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.B ELOOP
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A loop exists in symbolic links encountered during resolution of the
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\fIpath\fP argument.
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.TP 7
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.B ENAMETOOLONG
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The length of a pathname exceeds {PATH_MAX} or a pathname component
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is longer than {NAME_MAX}.
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.TP 7
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.B ENOENT
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A component of \fIpath\fP does not name an existing file or \fIpath\fP
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is an empty string.
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.TP 7
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.B ENOTDIR
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A component of the path prefix of \fIpath\fP is not a directory.
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.TP 7
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.B EOPNOTSUPP
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The \fIpath\fP argument names a symbolic link and the implementation
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does not support setting the owner or group of a symbolic
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link.
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.TP 7
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.B EPERM
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The effective user ID does not match the owner of the file and the
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process does not have appropriate privileges.
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.TP 7
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.B EROFS
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The file resides on a read-only file system.
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.sp
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.LP
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The \fIlchown\fP() function may fail if:
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.TP 7
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.B EIO
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An I/O error occurred while reading or writing to the file system.
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.TP 7
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.B EINTR
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A signal was caught during execution of the function.
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.TP 7
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.B ELOOP
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More than {SYMLOOP_MAX} symbolic links were encountered during resolution
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of the \fIpath\fP argument.
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.TP 7
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.B ENAMETOOLONG
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Pathname resolution of a symbolic link produced an intermediate result
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whose length exceeds {PATH_MAX}.
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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 Changing the Current Owner of a File
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.LP
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The following example shows how to change the ownership of the symbolic
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link named \fB/modules/pass1\fP to the user ID
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associated with "jones" and the group ID associated with "cnd".
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.LP
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The numeric value for the user ID is obtained by using the \fIgetpwnam\fP()
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function.
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The numeric value for the group ID is obtained by using the \fIgetgrnam\fP()
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function.
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.sp
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.RS
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.nf
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\fB#include <sys/types.h>
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#include <unistd.h>
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#include <pwd.h>
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#include <grp.h>
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.sp
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struct passwd *pwd;
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struct group *grp;
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char *path = "/modules/pass1";
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\&...
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pwd = getpwnam("jones");
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grp = getgrnam("cnd");
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lchown(path, pwd->pw_uid, grp->gr_gid);
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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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On implementations which support symbolic links as directory entries
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rather than files, \fIlchown\fP() may fail.
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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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\fIchown\fP() , \fIsymlink\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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