CHFLAGS(2)                    System Calls Manual                   CHFLAGS(2)

NAME
     chflags, fchflags – set file flags

SYNOPSIS
     #include <sys/stat.h>
     #include <unistd.h>

     int
     chflags(const char *path, u_int flags);

     int
     fchflags(int fd, u_int flags);

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

     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_OPAQUE      The directory is opaque when viewed through a union
                          stack.
           UF_HIDDEN      The file or directory is not intended to be
                          displayed to the user.
           UF_COMPRESSED  File is compressed at the file system level.
           SF_ARCHIVED    The file has been archived.
           SF_IMMUTABLE   The file may not be changed.
           SF_APPEND      The file may only be appended to.
           SF_DATALESS    The file is a dataless placeholder.  The system will
                          attempt to materialize it when accessed according to
                          the dataless file materialization policy of the
                          accessing thread or process.  See getiopolicy_np(3).

     The “UF_IMMUTABLE”, “UF_APPEND”, “UF_OPAQUE”, and “UF_HIDDEN” flags may
     be set or unset by either the owner of a file or the super-user.

     The “SF_ARCHIVED”, “SF_IMMUTABLE” and “SF_APPEND” flags may only be set
     or unset by the super-user.

     The “SF_DATALESS” and “UF_COMPRESSED” flags are internal flags and may
     not be set or unset from user space.  Attempting to modify them using
     chflags() will result in undefined behaviour.

RETURN VALUES
     Upon successful completion, a value of 0 is returned.  Otherwise, -1 is
     returned and the global variable errno is set to indicate the error.

ERRORS
     chflags() will fail if:

     [ENOTDIR]          A component of the path prefix is not a directory.

     [ENAMETOOLONG]     A component of a pathname exceeded {NAME_MAX}
                        characters, or an entire path name exceeded {PATH_MAX}
                        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.

     [EROFS]            The named file resides on a read-only file system.

     [EFAULT]           Path points outside the process's allocated address
                        space.

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

     [ENOTSUP]          The operation isn't supported by the filesystem.

     fchflags() will fail if:

     [EBADF]            The descriptor is not valid.

     [EINVAL]           fd 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.

     [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.

     [ENOTSUP]          The operation isn't supported by the filesystem.

SEE ALSO
     chflags(1), fflagstostr(3), lchflags(3), strtofflags(3), launchd(8)

HISTORY
     The chflags() and fchflags functions first appeared in 4.4BSD.

macOS 15.2                       June 9, 1993                       macOS 15.2