---
name: "dcalc"
section: "1"
platform: "linux"
package: "sleuthkit"
version: "2.52-1"
release: "Debian 5.0 (Lenny)"
platforms: ["linux"]
url: "https://new.carta.tech/dcalc"
---

# dcalc(1)

Converts between unallocated disk unit numbers and regular disk unit numbers.

## NAME

dcalc - Converts between unallocated disk unit numbers and regular disk unit numbers.

## SYNOPSIS

**dcalc** \[-dsu unit\_addr\] \[-vV\] \[-i imgtype\] \[-o imgoffset\] \[-f fstype\] image \[images\]

## DESCRIPTION

**dcalc** creates a disk unit number mapping between two images, one normal and  another that only contains the unallocated units of the first (the default behavior of the  **[dls(1)](/dls/1.md)** program).  One of the  **-d, -s,** or  **-u** options must be given.  If the  **-d** option is given, then the **unit\_addr** value is the disk unit address in the regular image (i.e. from  **[dd(1)](/dd/1.md)** ). If the unit is unallocated, its address in an unallocated image is given.  If the  **-u** option is given, then the  **unit\_addr** value is the disk unit address in the unallocated unit image (i.e.  from  **[dls(1)](/dls/1.md)** ).  Its disk unit address in the original image is determined.  If the  **-s** option is given, then the **unit\_addr** value is the disk unit address in the slack image (i.e. from dls -s).   The **image** is the full, original image (i.e. from [dd(1)](/dd/1.md)).

- \-f fstype

  Identify the File System type of the image.  Use the -? argument for a list of supported file system types. If not given, the default type for the platform is used.

- \-i imgtype

  Identify the type of image file, such as raw or split.  Raw is the default.

- \-o imgoffset

  The sector offset where the file system starts in the image.  Non-512 byte sectors can be specified using '@' (32@2048)

- \-v

  Verbose output to STDERR.

- \-V

  Display version.

This is useful when using  **lazarus** or keyword searching an image generated by **dls.** This allows one to identify the original unit address and provides  better documentation.

## EXAMPLE

\# dcalc -u 64 images/wd0e

## SEE ALSO

[**dd**(1)](/dd/1.md), [**dls**(1)](/dls/1.md), [**lazarus**(1)](/lazarus/1.md)

## HISTORY

**dcalc** first appeared in **TCTUTILs** v1.01. as **blockcalc.**

## AUTHOR

Brian Carrier \<carrier@sleuthkit.org\>