fchflags(2) set file flags

Other Alias

chflags, lchflags

LIBRARY

Lb libc

SYNOPSIS

In sys/stat.h In unistd.h Ft int Fn chflags const char *path u_long flags Ft int Fn lchflags const char *path int flags Ft int Fn fchflags int fd u_long flags

DESCRIPTION

The file whose name is given by Fa path or referenced by the descriptor Fa fd has its flags changed to Fa flags .

The Fn lchflags system call is like Fn chflags except in the case where the named file is a symbolic link, in which case Fn 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 values

UF_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.

If one of 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

Rv -std

ERRORS

The Fn chflags system call will fail if:

Bq Er ENOTDIR
A component of the path prefix is not a directory.
Bq Er ENAMETOOLONG
A component of a pathname exceeded 255 characters, or an entire path name exceeded 1023 characters.
Bq Er ENOENT
The named file does not exist.
Bq Er EACCES
Search permission is denied for a component of the path prefix.
Bq Er ELOOP
Too many symbolic links were encountered in translating the pathname.
Bq Er EPERM
The effective user ID does not match the owner of the file and the effective user ID is not the super-user.
Bq Er EPERM
One of SF_IMMUTABLE , SF_APPEND or SF_NOUNLINK is set and the user is either not the super-user or securelevel is greater than 0.
Bq Er EPERM
A non-super-user tries to set one of SF_IMMUTABLE , SF_APPEND or SF_NOUNLINK
Bq Er EPERM
User tries to set or remove the SF_SNAPSHOT flag.
Bq Er EROFS
The named file resides on a read-only file system.
Bq Er EFAULT
The Fa path argument points outside the process's allocated address space.
Bq Er EIO
An I/O error occurred while reading from or writing to the file system.
Bq Er EOPNOTSUPP
The underlying file system does not support file flags.

The Fn fchflags system call will fail if:

Bq Er EBADF
The descriptor is not valid.
Bq Er EINVAL
The Fa fd argument refers to a socket, not to a file.
Bq Er EPERM
The effective user ID does not match the owner of the file and the effective user ID is not the super-user.
Bq Er EPERM
One of SF_IMMUTABLE , SF_APPEND or SF_NOUNLINK is set and the user is either not the super-user or securelevel is greater than 0.
Bq Er EPERM
A non-super-user tries to set one of SF_IMMUTABLE , SF_APPEND or SF_NOUNLINK
Bq Er EROFS
The file resides on a read-only file system.
Bq Er EIO
An I/O error occurred while reading from or writing to the file system.
Bq Er EOPNOTSUPP
The underlying file system does not support file flags.

HISTORY

The Fn chflags and Fn fchflags system calls first appeared in BSD 4.4