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       magicrescue - Scans a block device and extracts known file types by
       looking at magic bytes.


       magicrescue [ options ] devices


       Magic Rescue opens devices for reading, scans them for file types it
       knows how to recover and calls an external program to extract them.  It
       looks at "magic bytes" in file contents, so it can be used both as an
       undelete utility and for recovering a corrupted drive or partition.  It
       works on any file system, but on very fragmented file systems it can
       only recover the first chunk of each file.  These chunks are sometimes
       as big as 50MB, however.

       To invoke magicrescue, you must specify at least one device and the -d
       and -r options.  See the "USAGE" section in this manual for getting


       -b blocksize
              Default: 1.  This will direct magicrescue to only consider files
              that start at a multiple of the blocksize argument.  The option
              applies only to the recipes following it, so by specifying it
              multiple times it can be used to get different behavior for
              different recipes.

              Using this option you can usually get better performance, but
              fewer files will be found.  In particular, files with leading
              garbage (e.g. many mp3 files) and files contained inside other
              files are likely to be skipped.  Also, some file systems don’t
              align small files to block boundaries, so those won’t be found
              this way either.

              If you don’t know your file system’s block size, just use the
              value 512, which is almost always the hardware sector size.

       -d directory
              Mandatory.  Output directory for found files.  Make sure you
              have plenty of free space in this directory, especially when
              extracting very common file types such as jpeg or gzip files.
              Also make sure the file system is able to handle thousands of
              files in a single directory, i.e. don’t use FAT if you are
              extracting many files.

              You should not place the output directory on the same block
              device you are trying to rescue files from.  This might add the
              same file to the block device ahead of the current reading
              position, causing magicrescue to find the same file again later.
              In the worst theoretical case, this could cause a loop where the
              same file is extracted thousands of times until disk space is
              exhausted.  You are also likely to overwrite the deleted files
              you were looking for in the first place.

       -r recipe
              Mandatory.  Recipe name, file, or directory.  Specify this as
              either a plain name (e.g.  "jpeg-jfif") or a path (e.g.
              recipes/jpeg-jfif).  If it doesn’t find such a file in the
              current directory, it will look in ./recipes and
              PREFIX/share/magicrescue/recipes, where PREFIX is the path you
              installed to, e.g. /usr/local.

              If recipe is a directory, all files in that directory will be
              treated as recipes.

              Browse the PREFIX/share/magicrescue/recipes directory to see
              what recipes are available.  A recipe is a text file, and you
              should read the comments inside it before using it.  Either use
              the recipe as it is or copy it somewhere and modify it.

              For information on creating your own recipes, see the "RECIPES"

       -I file
              Reads input files from file in addition to those listed on the
              command line.  If file is "-", read from standard input.  Each
              line will be interpreted as a file name.

       -M output_mode
              Produce machine-readable output to stdout.  output_mode can be:

              i   Print each input file name before processing

              o   Print each output file name after processing

              io  Print both input and output file names.  Input file names
                  will be prefixed by "i" and a space.  Output file names will
                  be prefixed by "o" and a space.

              Nothing else will be written to standard output in this mode.

       -O [+|-|=][0x]offset
              Resume from the specified offset in the first device.  If
              prefixed with 0x it will be interpreted as a hex number.

              The number may be prefixed with a sign:

              =   Seek to an absolute position (default)

              +   Seek to a relative position.  On regular files this does the
                  same as the above.

              -   Seek to EOF, minus the offset.


       Say you have destroyed the file system on /dev/hdb1 and you want to
       extract all the jpeg files you lost.  This guide assumes you have
       installed Magic Rescue in /usr/local, which is the default.

       Make sure DMA and other optimizations are enabled on your disk, or it
       will take hours.  In Linux, use hdparm to set these options:

           $ hdparm -d 1 -c 1 -u 1 /dev/hdb

       Choose your output directory, somewhere with lots of disk space.

           $ mkdir ~/output

       Look in the /usr/local/share/magicrescue/recipes directory for the
       recipes you want.  Magic Rescue comes with recipes for some common file
       types, and you can make your own too (see the next section).  Open the
       recipes you want to use in a text editor and read their comments.  Most
       recipes require 3rd party software to work, and you may want to modify
       some parameters (such as min_output_file) to suit your needs.

       Then invoke magicrescue

           $ magicrescue -r jpeg-jfif -r jpeg-exif -d ~/output /dev/hdb1

       It will scan through your entire hard disk, so it may take a while.
       You can stop it and resume later of you want to.  To do so, interrupt
       it (with CTRL+C) and note the progress information saying what address
       it got to.  Then restart it later with the -O option.

       When it has finished you will probably find thousands of .jpg files in
       ~/output, including things you never knew was in your browser cache.
       Sorting through all those files can be a huge task, so you may want to
       use software or scripts to do it.

       First, try to eliminate duplicates with the dupemap(1) tool included in
       this package.

           $ dupemap delete,report ~/output

       If you are performing an undelete operation you will want to get rid of
       all the rescued files that also appear on the live file system.  See
       the dupemap(1) manual for instructions on doing this.

       If that’s not enough, you can use use magicsort(1) to get a better

           $ magicsort ~/output


   Creating recipe files
       A recipe file is a relatively simple file of 3-5 lines of text.  It
       describes how to recognise the beginning of the file and what to do
       when a file is recognised.  For example, all jfif images start with the
       bytes "0xff 0xd8".  At the 6th byte will be the string "JFIF".  Look at
       recipes/jpeg-jfif in the source distribution to follow this example.

       Matching magic data is done with a "match operation" that looks like

       offset operation parameter

       where offset is a decimal integer saying how many bytes from the
       beginning of the file this data is located, operation refers to a
       built-in match operation in magicrescue, and parameter is specific to
       that operation.

       ·   The string operation matches a string of any length.  In the jfif
           example this is four bytes.  You can use escape characters, like
           "\n" or "\xA7".

       ·   The int32 operation matches 4 bytes ANDed with a bit mask.  To
           match all four bytes, use the bit mask "FFFFFFFF".  If you have no
           idea what a bit mask is, just use the string operation instead.
           The mask "FFFF0000" in the jfif example matches the first two

       ·   The char operation is like "string", except it only matches a
           single character.

       To learn these patterns for a given file type, look at files of the
       desired type in a hex editor, search through the resource files for the
       file(1) utility (<>) and/or search
       the Internet for a reference on the format.

       If all the operations match, we have found the start of the file.
       Finding the end of the file is a much harder problem, and therefore it
       is delegated to an external shell command, which is named by the
       command directive.  This command receives the block device’s file
       descriptor on stdin and must write to the file given to it in the $1
       variable.  Apart from that, the command can do anything it wants to try
       and extract the file.

       For some file types (such as jpeg), a tool already exists that can do
       this.  However, many programs misbehave when told to read from the
       middle of a huge block device.  Some seek to byte 0 before reading (can
       be fixed by prefixing cat|, but some refuse to work on a file they
       can’t seek in).  Others try to read the whole file into memory before
       doing anything, which will of course fail on a muti-gigabyte block
       device.  And some fail completely to parse a partially corrupted file.

       This means that you may have to write your own tool or wrap an existing
       program in some scripts that make it behave better.  For example, this
       could be to extract the first 10MB into a temporary file and let the
       program work on that.  Or perhaps you can use tools/safecat if the file
       may be very large.

   Recipe format reference
       Empty lines and lines starting with "#" will be skipped.  A recipe
       contains a series of match operations to find the content and a series
       of directives to specify what to do with it.

       Lines of the format offset operation parameter will add a match
       operation to the list.  Match operations will be tried in the order
       they appear in the recipe, and they must all match for the recipe to
       succeed.  The offset describes what offset this data will be found at,
       counting from the beginning of the file.  operation can have the
       following values:

       string string
              The parameter is a character sequence that may contain escape
              sequences such as \xFF.

       char character
              The parameter is a single character (byte), or an escape

       int32 value bitmask
              Both value and bitmask are expressed as 8-character hex strings.
              bitmask will be ANDed with the data, and the result will be
              compared to value.  The byte order is as you see it in the hex
              editor, i.e. big-endian.

       The first match operation in a recipe is special, it will be used to
       scan through the file.  Only the char and string operations can be used
       there.  To add more operation types, look at the instructions in

       A line that doesn’t start with an integer is a directive.  This can be:

       extension ext
              Mandatory.  ext names the file extension for this type, such as

       command command
              Mandatory.  When all the match operations succeed, this command
              will be executed to extract the file from the block device.
              command is passed to the shell with the block device’s file
              descriptor (seeked to the right byte) on stdin.  The shell
              variable $1 will contain the file its output should be written
              to, and it must respect this.  Otherwise magicrescue cannot tell
              whether it succeeded.

       rename command
              Optional.  After a successful extraction this command will be
              run.  Its purpose is to gather enough information about the file
              to rename it to something more meaningful.  The script must not
              perform the rename command itself, but it should write to
              standard output the string "RENAME", followed by a space,
              followed by the new file name.  Nothing else must be written to
              standard output.  If the file should not be renamed, nothing
              should be written to standard output.  Standard input and $1
              will work like with the command directive.

       min_output_file size
              Default: 100.  Output files less than this size will be deleted.

       allow_overlap bytes
              By default, recipes will not match on overlapping byte ranges.
              allow_overlap disables this, and it should always be used for
              recipes where the extracted file may be larger than it was on
              disk.  If bytes is negative, overlap checking will be completely
              disabled.  Otherwise, overlap checking will be in effect for
              everything but the last bytes of the output.  For example, if
              the output may be up to 512 bytes bigger than the input,
              allow_overlap should be set to 512.

       To test whether your recipe actually works, either just run it on your
       hard disk or use the tools/checkrecipe script to pick out files that
       should match but don’t.

       If you have created a recipe that works, please mail it to me at so I can include it in the distribution.


       Magic Rescue is not meant to be a universal application for file
       recovery.  It will give good results when you are extracting known file
       types from an unusable file system, but for many other cases there are
       better tools available.

       ·   If there are intact partitions present somewhere, use gpart to find

       ·   If file system’s internal data structures are more or less
           undamaged, use The Sleuth Kit.  At the time of writing, it only
           supports NTFS, FAT, ext[23] and FFS, though.

       ·   If Magic Rescue does not have a recipe for the file type you are
           trying to recover, try foremost instead.  It recognizes more file
           types, but in most cases it extracts them simply by copying out a
           fixed number of bytes after it has found the start of the file.
           This makes postprocessing the output files more difficult.

       In many cases you will want to use Magic Rescue in addition to the
       tools mentioned above.  They are not mutually exclusive, e.g. combining
       magicrescue with dls from The Sleuth Kit could give good results.  In
       many cases you’ll want to use magicrescue to extract its known file
       types and another utility to extract the rest.

       When combining the results of more than one tool, dupemap(1) can be
       used to eliminate duplicates.


       Similar programs
               <>.  Tries to
               rebuild the partition table by scanning the disk for lost

               <>.  Does the same thing as
               magicrescue, except that its "recipes" are less complex.
               Finding the end of the file must happen by either matching an
               EOF string or just extracting a fixed number of bytes every
               time.  It supports more file types than Magic Rescue, but
               extracted files usually have lots of trailing garbage, so
               removal of duplicates and sorting by size is not possible.

           The Sleuth Kit
               <>.  This popular package of
               utilities is extremely useful for undeleting files from a
               FAT/NTFS/ext2/ext3/FFS file system that’s not completely
               corrupted.  Most of the utilities are not very useful if the
               file system has been corrupted or overwritten.  It is based on
               The Coroner’s Toolkit

           JPEG recovery tools
               This seems to be the file type most people are trying to
               recover.  Available utilities include
               <>, and

       Getting disk images from failed disks
           dd(1), rescuept(1), <>,

       Processing magicrescue’s output
           dupemap(1), file(1), magicsort(1), <>

       Authoring recipes
           magic(4), hexedit(1), <>

       Filesystem-specific undelete utilities
           There are too many to count them, especially for ext2 and FAT.
           Find them on Google and Freshmeat.


       Jonas Jensen <>


       You can find the latest version at