System Administration Commands fsdbudfs(1M)
NAME
fsdbudfs - udfs file system debugger
SYNOPSIS
fsdb [-F] udfs [genericoption] [-o specificoption] special
DESCRIPTION
The fsdbudfs command is an interactive tool that can be
used to patch up a damaged udfs file system. fsdbudfs has
conversions to translate block and i-numbers into their
corresponding disk addresses. Mnemonic offsets to access
different parts of an inode are also included. Mnemonic
offsets greatly simplify the process of correcting control
block entries or descending the file system tree.
fsdb contains several error-checking routines to verify
inode and block addresses. These can be disabled if neces-
sary by invoking fsdb with the -o option or by using the o
command.
fsdb reads one block at a time, and therefore works with raw
as well as block I/O devices. A buffer management routine is
used to retain commonly used blocks of data in order to
reduce the number of read system calls. All assignment
operations result in an immediate write-through of the
corresponding block. In order to modify any portion of the
disk, fsdb must be invoked with the -w option.
Wherever possible, adb-like syntax has been adopted to pro-
mote the use of fsdb through familiarity.
OPTIONS
The following options are supported:
-o specificoption Specify udfs file system specific
options in a comma-separated list with
no intervening spaces. The following
specific options are supported:
o Override some error condi-
tions.
p=string Set prompt to string.
w Open for write.
SunOS 5.11 Last change: 11 Jun 1999 1
System Administration Commands fsdbudfs(1M)
? Display usage.
USAGE
Numbers are considered hexadecimal by default. The user has
control over how data is to be displayed or accepted. The
base command displays or sets the input and output base.
Once set, all input defaults to this base and all output
displays in this base. The base can be overriden temporarily
for input by preceding hexadecimal numbers by 0x, preceding
decimal numbers with a 0t, or octal numbers with a 0. Hexa-
decimal numbers beginning with a-f or A -F must be preceded
with a 0x to distinguish them from commands.
Disk addressing by fsdb is at the byte level. However, fsdb
offers many commands to convert a desired inode, directory
entry, block, and so forth, to a byte address. After the
address has been calculated, fsdb records the result in the
current address (dot).
Several global values are maintained by fsdb:
o Current base (referred to as base)
o Current address (referred to as dot)
o Current inode (referred to as inode)
o Current count (referred to as count)
o Current type (referred to as type)
Most commands use the preset value of dot in their execu-
tion. For example,
> 2:inode
first sets the value of dot (.) to 2, colon (:), signifies
the start of a command, and the inode command sets inode to
2. A count is specified after a comma (,). Once set, count
remains at this value until a new command is encountered
that resets the value back to 1 (the default).
SunOS 5.11 Last change: 11 Jun 1999 2
System Administration Commands fsdbudfs(1M)
So, if
> 2000,400/X
is entered, 400 hex longs are listed from 2000, and when
completed, the value of dot is 2000 ] 400 * sizeof (long).
If a RETURN is then entered, the output routine uses the
current values of dot, count, and type and displays 400 more
hex longs. An asterisk (*) causes the entire block to be
displayed. An example showing several commands and the use
of RETURN would be:
> 2:ino; 0:dir?d
or
> 2:ino; 0:db:block?d
The two examples are synonymous for getting to the first
directory entry of the root of the file system. Once there,
subsequently entering a RETURN, plus (]), or minus (-)
advances to subsequent entries. Notice that
> 2:inode; :ls
or
> :ls /
is again synonymous.
Expressions
The following symbols are recognized by fsdb:
RETURN Update the value of dot by the current value of
type and display using the current value of
count.
SunOS 5.11 Last change: 11 Jun 1999 3
System Administration Commands fsdbudfs(1M)
# Update the value of dot by specifying a numeric
expression. Specify numeric expressions using
addition, subtraction, mulitiplication, and
division operators ( ], -, *, and %). Numeric
expressions are evaluated from left to right
and can use parentheses. After evaluation, the
value of dot is updated.
, count Update the count indicator. The global value of
count is updated to count. The value of count
remains until a new command is run. A count
specifier of * attempts to show a blocks's
worth of information. The default for count is
1.
? f Display in structured style with format specif-
ier f. See Formatted Output.
/ f Display in unstructured style with format
specifier f. See Formatted Output.
. Display the value of dot.
]e Increment the value of dot by the expression e.
The amount actually incremented is dependent on
the size of type: dot = dot ] e * sizeof (type)
The default for e is 1.
-e Decrement the value of dot by the expression e
. See ].
*e Multiply the value of dot by the expression e.
Multiplication and division don't use type. In
the above calculation of dot, consider the
sizeof (type) to be 1.
%e Divide the value of dot by the expression e.
See *.
< name Restore an address saved in register name. name
must be a single letter or digit.
SunOS 5.11 Last change: 11 Jun 1999 4
System Administration Commands fsdbudfs(1M)
> name Save an address in register name. name must be
a single letter or digit.
= f Display indicator. If f is a legitimate format
specifier (see Formatted Output), then the
value of dot is displayed using format specif-
ier f. Otherwise, assignment is assumed. See =
[s] [e].
= [s] [e] Change the value of dot using an assignment
indicator. The address pointed to by dot has
its contents changed to the value of the
expression e or to the ASCI representation of
the quoted (") string s. This can be useful for
changing directory names or ASCI file informa-
tion.
=] e Change the value of dot using an incremental
assignment. The address pointed to by dot has
its contents incremented by expression e.
=- e Change the value of dot using a decremental
assignment. Decrement the contents of the
address pointed to by dot by expression e.
Commands
A command must be prefixed by a colon (:). Only enough
letters of the command to uniquely distinguish it are
needed. Multiple commands can be entered on one line by
separating them by a SPACE, TAB, or semicolon (;).
To view a potentially unmounted disk in a reasonable manner,
fsdb supports the cd, pwd, ls, and find commands. The func-
tionality of each of these commands basically matches that
of its UNIX counterpart. See cd(1), pwd(1),ls(1), andfind(1)
for details. The *, ,, ?, and - wildcard characters are also
supported.
The following commands are supported:
base[=b]
Display or set the base. All input and output is
governed by the current base. Without the = b, displays
the current base. Otherwise, sets the current base to b.
SunOS 5.11 Last change: 11 Jun 1999 5
System Administration Commands fsdbudfs(1M)
Base is interpreted using the old value of base, so to
ensure correctness use the 0, 0t, or 0x prefix when
changing the base. The default for base is hexadecimal.
block
Convert the value of dot to a block address.
cd [dir]
Change the current directory to directory dir. The
current values of inode and dot are also updated. If dir
is not specified, changes directories to inode 2, root
(/).
directory
If the current inode is a directory, converts the value
of dot to a directory slot offset in that directory, and
dot now points to this entry.
file
Set the value of dot as a relative block count from the
beginning of the file. The value of dot is updated to
the first byte of this block.
find dir [-name n] [-inum i]
Find files by name or i-number. Recursively searches
directory dir and below for file names whose i-number
matches i or whose name matches pattern n. Only one of
the two options (-name or -inum) can be used at one
time. The find -print is not necessary or accepted.
fill=p
Fill an area of disk with pattern p. The area of disk is
delimited by dot and count.
inode
Convert the value of dot to an inode address. If suc-
cessful, the current value of inode is updated as well
as the value of dot. As a convenient shorthand, if
SunOS 5.11 Last change: 11 Jun 1999 6
System Administration Commands fsdbudfs(1M)
:inode appears at the beginning of the line, the value
of dot is set to the current inode and that inode is
displayed in inode format.
ls [ -R ] [-l ] pat1 pat2...
List directories or files. If no file is specified, the
current directory is assumed. Either or both of the
options can be used (but, if used, must be specified
before the filename specifiers). Wild card characters
are available and multiple arguments are acceptable. The
long listing shows only the i-number and the name; use
the inode command with ?i to get more information.
override
Toggle the value of override. Some error conditions
might be overridden if override is toggled to on.
prompt "p"
Change the fsdb prompt to p. p must be enclosed in
quotes.
pwd
Display the current working directory.
quit
Quit fsdb.
tag
Convert the value of dot and if this is a valid tag,
print the volume structure according to the tag.
!
Escape to the shell.
Inode Commands
In addition to the above commands, several other commands
deal with inode fields and operate directly on the current
SunOS 5.11 Last change: 11 Jun 1999 7
System Administration Commands fsdbudfs(1M)
inode (they still require the colon (:). They can be used to
more easily display or change the particular fields. The
value of dot is only used by the :db and :ib commands. Upon
completion of the command, the value of dot is changed so
that it points to that particular field. For example,
> :ln=]1
increments the link count of the current inode and sets the
value of dot to the address of the link count field.
The following inode commands are supported:
at Access time
bs Block size
ct Creation time
gid Group id
ln Link number
mt Modification time
md Mode
maj Major device number
min Minor device number
nm This command actually operates on the directory name
field. Once poised at the desired directory
entry (using the directory command), this command
allows you to change or display the directory name.
For example,
> 7:dir:nm="foo"
SunOS 5.11 Last change: 11 Jun 1999 8
System Administration Commands fsdbudfs(1M)
gets the 7th directory entry of the current inode
and changes its name to foo. Directory names cannot
be made larger than the field allows. If an attempt
is made to make a directory name larger than the
field allows,, the string is truncated to fit and a
warning message is displayed.
sz File size
uid User ID
uniq Unique ID
Formatted Output
Formatted output comes in two styles and many format types.
The two styles of formatted output are: structured and
unstructured. Structured output is used to display inodes,
directories, and so forth. Unstructured output displays raw
data.
Format specifiers are preceded by the slash (/) or question
mark (?) character. type is updated as necessary upon com-
pletion.
The following format specifiers are preceded by the ? char-
acter:
i Display as inodes in the current base.
d Display as directories in the current base.
The following format specifiers are preceded by the / char-
acter:
b Display as bytes in the current base.
c Display as characters.
o O Display as octal shorts or longs.
SunOS 5.11 Last change: 11 Jun 1999 9
System Administration Commands fsdbudfs(1M)
d D Display as decimal shorts or longs.
x X Display as hexadecimal shorts or longs.
EXAMPLES
Example 1 Using fsdb as a calculator for complex arithmetic
The following command displays 2010 in decimal format, and
is an example of using fsdb as a calculator for complex
arithmetic.
> 2000]400%(20]20)=D
Example 2 Using fsdb to display an i-number in idode fomat
The following command displays the i-number 386 in inode
format.386 becomes the current inode.
> 386:ino?i
Example 3 Using fsdb to change the link count
The following command changes the link count for the current
inode to 4.
> :ln=4
Example 4 Using fsdb to increment the link count
The following command increments the link count by 1.
> :ln=]1
SunOS 5.11 Last change: 11 Jun 1999 10
System Administration Commands fsdbudfs(1M)
Example 5 Using fsdb to display the creation time as a hexa-
decimal long
The following command displays the creation time as a hexa-
decimal long.
> :ct=X
Example 6 Using fsdb to display the modification time in
time format
The following command displays the modification time in time
format.
> :mt=t
Example 7 Using fsdb to display in ASCI
The following command displays, in ASCI, block 0 of the
file associated with the current inode.
> 0:file/c
Example 8 Using fsdb to display the directory enteries for
the root inode
The following command displays the first block's directory
entries for the root inode of this file system. This command
stops prematurely if the EOF is reached.
> 2:ino,*?d
Example 9 Using fsdb to change the current inode
SunOS 5.11 Last change: 11 Jun 1999 11
System Administration Commands fsdbudfs(1M)
The following command changes the current inode to that
associated with the 5th directory entry (numbered from 0) of
the current inode. The first logical block of the file is
then displayed in ASCI.
> 5:dir:inode; 0:file,*/c
Example 10 Using fsdb to change the i-number
The following command changes the i-number for the 7th
directory slot in the root directory to 3.
> 2:inode; 7:dir=3
Example 11 Using fsdb to change the name field
The following command changes the name field in the direc-
tory slot to name.
> 7:dir:nm="name"
Example 12 Using fsdb to display the a block
The following command displays the 3rd block of the current
inode as directory entries.
Example 13 Using fsdb to set the contents of address
The following command sets the contents of address 2050 to
0xffffffff. 0xffffffff can be truncated, depending on the
current type.
> 2050=0xffff
SunOS 5.11 Last change: 11 Jun 1999 12
System Administration Commands fsdbudfs(1M)
Example 14 Using fsdb to place an ASCI string at an address
The following command places the ASCI string this is some
text at address 1c92434.
> 1c92434="this is some text"
ATRIBUTES
See attributes(5) for descriptions of the following attri-
butes:
ATRIBUTE TYPE ATRIBUTE VALUE
Availability SUNWudf
SEE ALSO
clri(1M), fsckudfs(1M), dir(4), attributes(5)
SunOS 5.11 Last change: 11 Jun 1999 13
|
