---
name: "dwfilter"
section: "1"
platform: "linux"
package: "dwdiff"
version: "2.1.4-2+b3"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/dwfilter"
---

# dwfilter(1)

reformat text with dwdiff for further processing

## NAME

dwfilter - reformat text with dwdiff for further processing

## SYNOPSIS

**dwfilter** \[*OPTIONS*\] *OLD FILE* *NEW FILE* *POST PROCESSOR* \[*POST PROCESSOR OPTIONS*\]

## DESCRIPTION

**dwfilter** reformats the text in the old file according to the contents of the new file (or vice versa) and subsequently passes the reformated old file and the new file through a secondary filter. It's main use is to allow visual diff programs such as **meld** and **kdiff3** to be used, even though a text file has been reformated after editing. A further use is to allow the creation of small patches even when the new text has been reformated. **dwfilter** uses **dwdiff** for reformatting.

## OPTIONS

- **-r**, **--reverse**

  Reformat the new file based on the contents of the old file instead of the default where the old file is reformated based on the contents of the new file.

**dwfilter** accepts the following **dwdiff** options:

**-d** *delimiters*, **--delimiters**=*delimiters*\
 **-P**, **--punctuation**\
 **-W** *whitespace*, **--white-space**=*whitespace*\
 **-i**, **--ignore-case**\
 **-I**, **--ignore-formatting**\
 **-D** *option*, **--diff-option**=*option*\
 **-C***num*, **--context**=*num*\
 **-m***num*, **--match-context**=*num*\
 **--aggregate-changes**\
 **--wdiff-output**\
 **-A** *algorithm*,  **--algorithm**=*algorithm*\
 **--profile**=*name*, **--no-profile**

See the **dwdiff** manual page for the meaning.

A single dash (-) as a file can be used to denote standard input. Only one file can be read from standard input. To stop **dwfilter** from interpreting file names that start with a dash as options, one can specify a double dash (--) after which **dwfilter** will interpret any following arguments as files to read.

## BUGS

If you think you have found a bug, please check that you are using the latest version of **dwdiff** \<http://os.ghalkes.nl/dwdiff.html\>. When reporting bugs, please include a minimal example that demonstrates the problem.

## AUTHOR

G.P. Halkes \<dwdiff@ghalkes.nl\>

## COPYRIGHT

Copyright © 2006-2010 G.P. Halkes\
 dwdiff is licensed under the GNU General Public License version 3.\
 For more details on the license, see the file COPYING in the documentation directory. On Un\*x systems this is usually /usr/share/doc/dwdiff-$VERSION$.

## SEE ALSO

[**dwdiff**(1)](/dwdiff/1.md), [**diff**(1)](/diff/1.md), [**meld**(1)](/meld/1.md), [**kdiff3**(1)](/kdiff3/1.md)