NAME

       chflags, lchflags, fchflags — set file flags

LIBRARY

       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 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

       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, or SF_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_ARCHIVED,  SF_IMMUTABLE,  SF_APPEND, or
                          SF_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.

       The fchflags() system call will fail if:

       [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, or SF_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_ARCHIVED,  SF_IMMUTABLE,  SF_APPEND,  or
                          SF_NOUNLINK.

       [EPERM]            User tries to set or remove the SF_SNAPSHOT flag.

       [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.

Debian                                            Oct 29, 2010                                        CHFLAGS(2)