table of contents
CHFLAGS(2) | System Calls Manual | CHFLAGS(2) |
NAME¶
chflags, lchflags, fchflags — set file flagsLIBRARY¶
Standard C Library (libc, -lc)SYNOPSIS¶
#include <sys/stat.h>#include <unistd.h> int
chflags(const char *path, u_long flags); int
lchflags(const char *path, int flags); int
fchflags(int fd, u_long flags);
DESCRIPTION¶
The file whose name is given by path or referenced by the descriptor fd has its flags changed to flags. The lchflags() system call is like chflags() except in the case where the named file is a symbolic link, in which case lchflags() will change the flags of the link itself, rather than the file it points to. The flags specified are formed by or'ing the following valuesUF_NODUMP
- Do not dump the file.
UF_IMMUTABLE
- The file may not be changed.
UF_APPEND
- The file may only be appended to.
UF_NOUNLINK
- The file may not be renamed or deleted.
UF_OPAQUE
- The directory is opaque when viewed through a union stack.
SF_ARCHIVED
- The file may be archived.
SF_IMMUTABLE
- The file may not be changed.
SF_APPEND
- The file may only be appended to.
SF_NOUNLINK
- The file may not be renamed or deleted.
SF_SNAPSHOT
- The file is a snapshot file.
SF_IMMUTABLE
,
SF_APPEND
, or SF_NOUNLINK
is
set a non-super-user cannot change any flags and even the super-user can
change flags only if securelevel is greater than 0. (See
init(8) for details.)
The UF_IMMUTABLE
, UF_APPEND
,
UF_NOUNLINK
, UF_NODUMP
, and
UF_OPAQUE
flags may be set or unset by either the
owner of a file or the super-user.
The SF_IMMUTABLE
, SF_APPEND
,
SF_NOUNLINK
, and SF_ARCHIVED
flags may only be set or unset by the super-user. Attempts to set these flags
by non-super-users are rejected, attempts by non-superusers to clear flags
that are already unset are silently ignored. These flags may be set at any
time, but normally may only be unset when the system is in single-user mode.
(See init(8) for details.)
The SF_SNAPSHOT
flag is maintained by the system and
cannot be changed by any user.
RETURN VALUES¶
Upon successful completion, the value 0 is returned; otherwise the value -1 is returned and the global variable errno is set to indicate the error.ERRORS¶
The chflags() system call will fail if:- [
ENOTDIR
] - A component of the path prefix is not a directory.
- [
ENAMETOOLONG
] - A component of a pathname exceeded 255 characters, or an entire path name exceeded 1023 characters.
- [
ENOENT
] - The named file does not exist.
- [
EACCES
] - Search permission is denied for a component of the path prefix.
- [
ELOOP
] - Too many symbolic links were encountered in translating the pathname.
- [
EPERM
] - The effective user ID does not match the owner of the file and the effective user ID is not the super-user.
- [
EPERM
] - One of
SF_IMMUTABLE
,SF_APPEND
, orSF_NOUNLINK
is set and the user is either not the super-user or securelevel is greater than 0. - [
EPERM
] - A non-super-user tries to set one of
SF_IMMUTABLE
,SF_APPEND
, orSF_NOUNLINK
. - [
EPERM
] - User tries to set or remove the
SF_SNAPSHOT
flag. - [
EROFS
] - The named file resides on a read-only file system.
- [
EFAULT
] - The path argument points outside the process's allocated address space.
- [
EIO
] - An I/O error occurred while reading from or writing to the file system.
- [
EOPNOTSUPP
] - The underlying file system does not support file flags.
- [
EBADF
] - The descriptor is not valid.
- [
EINVAL
] - The fd argument refers to a socket, not to a file.
- [
EPERM
] - The effective user ID does not match the owner of the file and the effective user ID is not the super-user.
- [
EPERM
] - One of
SF_IMMUTABLE
,SF_APPEND
, orSF_NOUNLINK
is set and the user is either not the super-user or securelevel is greater than 0. - [
EPERM
] - A non-super-user tries to set one of
SF_IMMUTABLE
,SF_APPEND
, orSF_NOUNLINK
. - [
EROFS
] - The file resides on a read-only file system.
- [
EIO
] - An I/O error occurred while reading from or writing to the file system.
- [
EOPNOTSUPP
] - The underlying file system does not support file flags.
SEE ALSO¶
chflags(1), fflagstostr(3), strtofflags(3), init(8), mount_unionfs(8)HISTORY¶
The chflags() and fchflags() system calls first appeared in 4.4BSD.May 16, 2006 | Debian |