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FSDB(8)			FreeBSD	System Manager's Manual		       FSDB(8)

     fsdb -- FFS debugging/editing tool

     fsdb [-d] [-f] [-r] fsname

     The fsdb utility opens fsname (usually a raw disk partition) and runs a
     command loop allowing manipulation	of the file system's inode data.  You
     are prompted to enter a command with fsdb (inum X)> where X is the	cur-
     rently selected i-number.	The initial selected inode is the root of the
     file system (i-number 2).	The command processor uses the editline(3) li-
     brary, so you can use command line	editing	to reduce typing if desired.
     When you exit the command loop, the file system superblock	is marked
     dirty and any buffered blocks are written to the file system.

     The following options are available:

     -d	     Enable additional debugging output	(which comes primarily from
	     fsck(8)-derived code).

     -f	     Left for historical reasons and has no meaning.

     -r	     Open the file system read/only, and disables all commands that
	     would write to it.

     Besides the built-in editline(3) commands,	fsdb supports these commands:

     help    Print out the list	of accepted commands.

     inode i-number
	     Select inode i-number as the new current inode.

     back    Revert to the previously current inode.

     clri i-number
	     Clear i-number.

     lookup name
     cd	name
	     Find name in the current directory	and make its inode the current
	     inode.  Name may be a multi-component name	or may begin with
	     slash to indicate that the	root inode should be used to start the
	     lookup.  If some component	along the pathname is not found, the
	     last valid	directory encountered is left as the active inode.
	     This command is valid only	if the starting	inode is a directory.

     print   Print out the active inode.

     blocks  Print out the block list of the active inode.  Note that the
	     printout can become long for large	files, since all indirect
	     block pointers will also be printed.

     findblk disk_block_number ...
	     Find the inode(s) owning the specified disk block(s) number(s).
	     Note that these are not absolute disk blocks numbers, but offsets
	     from the start of the partition.

     uplink  Increment the active inode's link count.

	     Decrement the active inode's link count.

     linkcount number
	     Set the active inode's link count to number.

     ls	     List the current inode's directory	entries.  This command is
	     valid only	if the current inode is	a directory.

     rm	name
     del name
	     Remove the	entry name from	the current directory inode.  This
	     command is	valid only if the current inode	is a directory.

     ln	ino name
	     Create a link to inode ino	under the name name in the current di-
	     rectory inode.  This command is valid only	if the current inode
	     is	a directory.

     chinum dirslot inum
	     Change the	i-number in directory entry dirslot to inum.

     chname dirslot name
	     Change the	name in	directory entry	dirslot	to name.  This command
	     cannot expand a directory entry.  You can only rename an entry if
	     the name will fit into the	existing directory slot.

     chtype type
	     Change the	type of	the current inode to type.  Type may be	one
	     of: file, dir, socket, or fifo.

     chmod mode
	     Change the	mode bits of the current inode to mode.	 You cannot
	     change the	file type with this subcommand;	use chtype to do that.

     chflags flags
	     Change the	file flags of the current inode	to flags.

     chown uid
	     Change the	owner of the current inode to uid.

     chgrp gid
	     Change the	group of the current inode to gid.

     chgen gen
	     Change the	generation number of the current inode to gen.

     btime time
     mtime time
     ctime time
     atime time
	     Change the	creation (birth), modification,	change,	or access time
	     (respectively) on the current inode to time.  Time	should be in
	     the format	YYYYMMDDHHMMSS[.nsec] where nsec is an optional
	     nanosecond	specification.	If no nanoseconds are specified, the
	     birthnsec,	mtimensec, ctimensec, or atimensec field will be set
	     to	zero.  Note that btime is available on UFS2 file systems only.

     quit, q, exit, _EOF_
	     Exit the program.

     editline(3), fs(5), clri(8), fsck(8)

     The fsdb utility appeared in 4.3BSD-Tahoe.	 It used the source code for
     fsck(8) to	implement most of the file system manipulation code.  The re-
     mainder of	fsdb appeared in NetBSD	1.1 written by John T. Kohl.  It first
     appeared in FreeBSD 2.1.5 ported by Peter Wemm.

     Manipulation of ``short'' symlinks	has no effect.	In particular, one
     should not	try changing a symlink's type.

     You must specify modes as numbers rather than symbolic names.

     There are a bunch of other	things that you	might want to do which fsdb
     does not implement.

     Use this tool with	extreme	caution--you can damage	an FFS file system be-
     yond what fsck(8) can repair.

FreeBSD	13.0			October	3, 2016			  FreeBSD 13.0


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