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Newer page: version 2 Last edited on Monday, March 10, 2003 2:07:04 pm by PerryLorier
Older page: version 1 Last edited on Tuesday, June 4, 2002 12:23:42 am by perry Revert
@@ -1,207 +1,58 @@
-CHOWN  
-!!!CHOWN  
-NAME  
-SYNOPSIS  
-DESCRIPTION  
-RETURN VALUE  
-ERRORS  
-NOTES  
-CONFORMING TO  
-RESTRICTIONS  
-SEE ALSO  
-----  
 !!NAME 
-  
-  
-chown, fchown, lchown - change ownership of a file 
+lchown - change ownership of a file 
 !!SYNOPSIS 
+ #include <sys/types.h>  
+ #include <unistd.h>  
  
+ __int lchown(const char *__''path''__, uid_t__ ''owner''__, gid_t__ ''group''__);__  
  
-__#include __  
-#include __  
-  
-  
-__int chown(const char *__''path''__, uid_t__  
-''owner''__, gid_t__ ''group''__);  
-int fchown(int__ ''fd''__, uid_t__ ''owner''__,  
-gid_t__ ''group''__);  
-int lchown(const char *__''path''__, uid_t__  
-''owner''__, gid_t__  
-''group''__);__  
 !!DESCRIPTION 
+The owner of the file specified by ''path'' is changed. Only the super-user may change the owner of a file. The owner of a file may change the group of  
+the file to any group of which that owner is a member. The super-user may change the group arbitrarily.  
  
+If the ''owner'' or ''group'' is specified as -1, then that ID is not changed.  
  
-The owner of the file specified by ''path '' or by  
-''fd'' is changed. Only the super-user may change the  
-owner of a file . The owner of a file may change the group of  
-the file to any group of which that owner is a member. The  
-super-user may change the group arbitrarily
+When the owner or group of an executable file are changed by a non-super-user, the S_ISUID and S_ISGID mode bits are cleared. [POSIX] does not specify whether this also should happen when root does the ''chown ''; the Linux behaviour depends on the kernel version . In case of a non-group-executable file (with clear S_IXGRP bit) the  
+S_ISGID bit indicates mandatory locking, and is not cleared by a ''chown''
  
-  
-If the ''owner'' or ''group'' is specified as -1, then  
-that ID is not changed.  
-  
-  
-When the owner or group of an executable file are changed by  
-a non-super-user, the S_ISUID and S_ISGID mode bits are  
-cleared. POSIX does not specify whether this also should  
-happen when root does the ''chown''; the Linux behaviour  
-depends on the kernel version. In case of a  
-non-group-executable file (with clear S_IXGRP bit) the  
-S_ISGID bit indicates mandatory locking, and is not cleared  
-by a ''chown''.  
 !!RETURN VALUE 
+On success, zero is returned. On error, -1 is returned, and ''errno'' is set appropriately.  
  
-  
-On success, zero is returned. On error, -1 is returned, and  
-''errno'' is set appropriately.  
 !!ERRORS 
+Depending on the file system, other errors can be returned. The more general errors for chown(2) are listed below:  
  
  
-Depending on the file system , other errors can be returned .  
-The more general errors for __chown__ are listed  
-below:  
+;[EPERM]: The effective UID does not match the owner of the file, and is not zero; or the ''owner'' or ''group'' were specified incorrectly
  
+;[EROFS]: The named file resides on a read-only file system.  
  
-__EPERM__  
+;[EFAULT]: ''path'' points outside your accessible address space.  
  
+;[ENAMETOOLONG]: ''path'' is too long.  
  
-The effective UID does not match the owner of the file, and  
-is not zero; or the ''owner'' or ''group'' were  
-specified incorrectly
+;[ENOENT]: The file does not exist
  
+;[ENOMEM]: Insufficient kernel memory was available.  
  
-__EROFS__  
+;[ENOTDIR]: A component of the path prefix is not a directory.  
  
+;[EACCES]: Search permission is denied on a component of the path prefix.  
  
-The named file resides on a read-only file  
-system
+;[ELOOP]: Too many symbolic links were encountered in resolving ''path''
  
+;[EIO]: A low-level I/O error occurred while modifying the inode.  
  
-__EFAULT__  
-  
-  
-''path'' points outside your accessible address  
-space.  
-  
-  
-__ENAMETOOLONG__  
-  
-  
-''path'' is too long.  
-  
-  
-__ENOENT__  
-  
-  
-The file does not exist.  
-  
-  
-__ENOMEM__  
-  
-  
-Insufficient kernel memory was available.  
-  
-  
-__ENOTDIR__  
-  
-  
-A component of the path prefix is not a  
-directory.  
-  
-  
-__EACCES__  
-  
-  
-Search permission is denied on a component of the path  
-prefix.  
-  
-  
-__ELOOP__  
-  
-  
-Too many symbolic links were encountered in resolving  
-''path''.  
-  
-  
-The general errors for __fchown__ are listed  
-below:  
-  
-  
-__EBADF__  
-  
-  
-The descriptor is not valid.  
-  
-  
-__ENOENT__  
-  
-  
-See above.  
-  
-  
-__EPERM__  
-  
-  
-See above.  
-  
-  
-__EROFS__  
-  
-  
-See above.  
-  
-  
-__EIO__  
-  
-  
-A low-level I/O error occurred while modifying the  
-inode.  
 !!NOTES 
+Since Linux 2.1.81, chown(2) does follow symbolic links, and there is a new system call lchown(2) that does not follow symbolic links. Since Linux 2.1.86, this new call (that has the same semantics as the old chown(2)) has got the same syscall number, and chown(2) got the newly introduced number.  
  
-  
-In versions of Linux prior to 2.1.81 (and distinct from  
-2.1.46), __chown__ did not follow symbolic links. Since  
-Linux 2.1.81, __chown__ does follow symbolic links, and  
-there is a new system call __lchown__ that does not  
-follow symbolic links. Since Linux 2.1.86, this new call  
-(that has the same semantics as the old __chown__) has  
-got the same syscall number, and __chown__ got the newly  
-introduced number.  
-  
-  
-The prototype for __fchown__ is only available if  
-___BSD_SOURCE__ is defined (either explicitly, or  
-implicitly, by not defining _POSIX_SOURCE or compiling with  
-the -ansi flag).  
 !!CONFORMING TO 
+The __chown__ call conforms to SVr4, SVID, POSIX, X/OPEN. The 4.4BSD version can only be used by the superuser (that is, ordinary users cannot give away files). SVr4 documents [EINVAL], [EINTR], [ENOLINK] and [EMULTIHOP] returns, but no [ENOMEM]. POSIX.1 does not document [ENOMEM] or [ELOOP] error conditions.  
  
-  
-The __chown__ call conforms to SVr4, SVID, POSIX, X/OPEN.  
-The 4.4BSD version can only be used by the superuser (that  
-is, ordinary users cannot give away files). SVr4 documents  
-EINVAL, EINTR, ENOLINK and EMULTIHOP returns, but no ENOMEM.  
-POSIX.1 does not document ENOMEM or ELOOP error  
-conditions.  
-  
-  
- The __fchown__ call conforms to 4.4BSD and SVr4. SVr4  
- documents additional EINVAL, EIO, EINTR, and ENOLINK error  
- conditions. 
+The __fchown__ call conforms to 4.4BSD and SVr4. SVr4 documents additional [ EINVAL] , [ EIO] , [ EINTR] , and [ ENOLINK] error conditions. 
 !!RESTRICTIONS 
+The chown(2) semantics are deliberately violated on NFS file systems which have UID mapping enabled. Additionally, the semantics of all system calls which access  
+the file contents are violated, because chown(2) may cause immediate access revocation on already open files. Client side caching may lead to a delay between the time  
+where ownership have been changed to allow access for a user and the time where the file can actually be accessed by the user on other clients.  
  
-  
-The __chown__() semantics are deliberately violated on  
-NFS file systems which have UID mapping enabled.  
-Additionally, the semantics of all system calls which access  
-the file contents are violated, because __chown__() may  
-cause immediate access revocation on already open files.  
-Client side caching may lead to a delay between the time  
-where ownership have been changed to allow access for a user  
-and the time where the file can actually be accessed by the  
-user on other clients.  
 !!SEE ALSO 
-  
-  
 chmod(2), flock(2) 
-----  
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