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

NAME

     fsdb -- FFS debugging/editing tool

SYNOPSIS

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

DESCRIPTION

     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 currently selected i-number.  The initial selected inode is the root
     of the file system (i-number 2).  The command processor uses the editline(3) library, 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.

COMMANDS

     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.

     active
     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.

     downlink
	     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 directory 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.

SEE ALSO

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

HISTORY

     The fsdb utility uses the source code for fsck(8) to implement most of the file system manipulation code.	The remainder of fsdb first
     appeared in NetBSD, written by John T. Kohl.

     Peter Wemm ported it to FreeBSD.

BUGS

     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.

WARNING

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

BSD
								  August 24, 2006							       BSD