fchown(2)

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUES | ERRORS | ATTRIBUTES | SUMMARY OF TRUSTED SOLARIS CHANGES | SEE ALSO

NAME

chown, lchown, fchown- change owner and group of a file

SYNOPSIS

#include <unistd.h>
#include <sys/types.h>

int chown(const char *path, uid_t owner, gid_t group);
int lchown(const char *path, uid_t owner, gid_t group);
int fchown(int fildes, uid_t owner, gid_t group);

DESCRIPTION

The chown() function sets the owner ID and group ID of the file specified by path or referenced by the open file descriptor fildes to owner and group respectively. If owner or group is specified as -1, chown() does not change the corresponding ID of the file.

The lchown() function sets the owner ID and group ID of the named file in the same manner as chown(), unless the named file is a symbolic link. In this case, lchown() changes the ownership of the symbolic link file itself, while chown() changes the ownership of the file or directory to which the symbolic link refers.

If chown(), lchown(), or fchown() is invoked, the set-user-ID and set-group-ID bits of the file mode, chmod(2). respectively, are cleared. See chmod(2). To bypass this restriction, the process may assert the PRIV_FILE_SETID privilege.

The operating system has a configuration option, _POSIX_CHOWN_RESTRICTED, to restrict ownership changes for the chown(), lchown(), and fchown() functions. When _POSIX_CHOWN_RESTRICTED is not in effect, the effective user ID of the process must match the owner of the file. To override this restriction, the calling process must assert the PRIV_FILE_CHOWN privilege. When _POSIX_CHOWN_RESTRICTED is not in effect, the effective user ID of the process must match the owner of the file or the process must be the super-user to change the ownership of a file. When _POSIX_CHOWN_RESTRICTED is in effect, the chown(), lchown(), and fchown() functions require that the calling process assert the PRIV_FILE_CHOWN privilege to change the user ID of a file. To change the group ID of a file, the process must be the owner of the file and the new group ID must be the group of the process ID or must be in the supplementary group list of the process. To override this restriction, the calling process may assert the PRIV_FILE_CHOWN privilege.

---

set rstchown = 1

---

To disable this option, include the following line in /etc/system:

---

set rstchown = 0

---

See system(4) and fpathconf(2).

Upon successful completion, chown(), fchown() and lchown() mark for update the st_ctime field of the file.

RETURN VALUES

chown() returns:

0

On success.

-1

On failure, and sets errno to indicate the error.

ERRORS

The chown() and lchown() functions will fail if:

EACCES

Search permission is denied on a component of the path prefix of path. To override this restriction, the calling process may assert one or both of these privileges: PRIV_FILE_DAC_SEARCH and PRIV_FILE_MAC_SEARCH.

Write permission is denied on path or fildes. To override this restriction, the calling process may assert the PRIV_FILE_MAC_WRITE privilege.

EFAULT

The path argument points to an illegal address.

EINTR

A signal was caught during the execution of the chown() or lchown() function.

EINVAL

The group or owner argument is out of range.

EIO

An I/O error occurred while reading from or writing to the file system.

ELOOP

Too many symbolic links were encountered in translating path.

ENAMETOOLONG

The length of the path argument exceeds PATH_MAX, or the length of a path component exceeds NAME_MAX while _POSIX_NO_TRUNC is in effect.

ENOLINK

The path argument points to a remote machine and the link to that machine is no longer active.

ENOENT

Either a component of the path prefix or the file referred to by path does not exist or is a null pathname.

ENOTDIR

A component of the path prefix of path is not a directory.

EPERM

The effective user ID does not match the owner of the file. If _POSIX_CHOWN_RESTRICTED is set, the calling process must assert the PRIV_FILE_CHOWN privilege. If _POSIX_CHOWN_RESTRICTED is not set, the calling process may assert the PRIV_FILE_CHOWN privilege.

EROFS

The named file resides on a read-only file system.

The fchown() function will fail if:

EBADF

The fildes argument is not an open file descriptor.

EIO

An I/O error occurred while reading from or writing to the file system.

EINTR

A signal was caught during execution of the function.

ENOLINK

The fildes argument points to a remote machine and the link to that machine is no longer active.

EINVAL

The group or owner argument is out of range.

EPERM

The effective user ID does not match the owner of the file, or the process is not the super-user and _POSIX_CHOWN_RESTRICTED indicates that such privilege is required.

EROFS

The named file referred to by fildes resides on a read-only file system.

ATTRIBUTES

See attributes(5) for descriptions of the following attributes:

ATTRIBUTE TYPE	ATTRIBUTE VALUE
MT-Level	chown() is Async-Signal-Safe

SUMMARY OF TRUSTED SOLARIS CHANGES

Appropriate privilege is required to override access checks.

When the ownership of path and fildes is changed, the set-user-ID and set-group-ID bits are cleared. The calling process may assert the PRIV_FILE_SETID privilege to bypass this restriction.

To change the user ID of the file when the calling process does not own the file and _POSIX_CHOWN_RESTRICTED is not in effect, the calling process may assert the PRIV_FILE_CHOWN privilege.

To change the group ID of the file when the calling process does not own the file, and the new group ID is not in the group ID of the process or in the supplementary group list of the process, and _POSIX_CHOWN_RESTRICTED is not in effect, the calling process may assert the PRIV_FILE_CHOWN privilege.

SEE ALSO

Trusted Solaris 8 4/01 Reference Manual

chgrp(1), chown(1), chmod(2)

SunOS 5.8 Reference Manual

attributes(5)

Trusted Solaris 8 4/01  Last Revised 30 Sep 1999

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUES | ERRORS | ATTRIBUTES | SUMMARY OF TRUSTED SOLARIS CHANGES | SEE ALSO