---
name: "uncrustify"
section: "1"
platform: "linux"
package: "uncrustify"
version: "0.83.0-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/uncrustify"
---

# uncrustify(1)

C, C++, C#, D, Java and Pawn source code beautifier

## NAME

uncrustify - C, C++, C#, D, Java and Pawn source code beautifier

## SYNOPSIS

**uncrustify \[*OPTIONS*\] \[*FILES*\]**

## DESCRIPTION

If no input files are specified, the input is read from stdin.\
 If reading from stdin, you should specify the language using -l.

If -F is used or files are specified on the command line, the output filename is *PFX* + "/" + filename + *SFX*.\
 Unless, of course, the options **--replace** or **--no-backup** are used.

When reading from stdin or doing a single file via the '-f' option, the output is dumped to stdout, unless redirected with -o FILE.

Errors are always dumped to stderr

## OPTIONS

### Basic Options:

- **-c** *CFG*

  Use the config file *CFG*, or defaults if *CFG* is set to '-'.\
   If not specified, uncrustify will use **$UNCRUSTIFY\_CONFIG** or **$HOME/.uncrustify.cfg**.

- **-f** *FILE*

  Process the single file *FILE*, sending output to stdout or the file specified with **-o**.

- **-o** *FILE*

  Redirect output to *FILE*.\
   Use with **-f**, **--update-config**, **--update-config-with-doc**, **--universalindent**.

- **--check**

  Do not output the new text, instead verify that nothing changes when the file(s) are processed. The status of every file is printed to stderr. The exit code is EXIT\_SUCCESS if there were no changes, EXIT\_FAILURE otherwise.

- **-F** *FILE*

  Read files to process from *FILE*, one filename per line.  If *FILE* is ´-´ then read filenames from standard input instead of a file.\
   You can create this file using something like ´**find . -name "\*.c" \> list.txt**´.\
   This cannot be combined with **-f**.

- **--prefix** *PFX*

  Prepend *PFX* to the output filename path.\
   This cannot be combined with **-f**, **--replace**, or **--no-backup**.

- **--suffix** *SFX*

  Append *SFX* to the output filename.\
   The default is '.uncrustify' if neither *SFX* or *PFX* are specified.\
   This cannot be combined with **-f**, **--replace**, or **--no-backup**.

- **--frag**

  Assume the input is a code fragment and the first line is properly indented.

- **--replace**

  Replace source files (creates a backup).\
   This cannot be combined with **-f**, **--prefix**, or **--suffix**.

- **--no-backup**

  Replace files, no backup. Useful if files are under source control\
   This cannot be combined with **-f**, **--prefix**, or **--suffix**.

- **--if-changed**

  Write to stdout (or create output FILE) only if a change was detected.\

- **--mtime**

  Preserve mtime on replaced files.

- **-l**

  Language override: C, CPP, D, CS, JAVA, PAWN, VALA, OC, OC+

- **-t**

  Load a file with types (usually not needed)

- **-q**

  Quiet mode - no output on stderr (**-L** will override)

### Config/Help Options:

- **-h** -? **--help** **--usage**

  Print this message and exit

- **--version**

  Print the version and exit

- **--count-options**

  Print the number of available options and exit

- **--show-config**

  Print out option documentation and exit

- **--update-config**

  Output a new config file.

- **--update-config-with-doc**

  Output a new config file with embedded usage comments.

- **--universalindent**

  Output a config file for Universal Indent GUI.

- **--detect**

  Detects the config from a source file. Use with '-f *FILE*'. Detection is currently fairly limited.

- **--tracking space:FILE**

  Prepare space tracking information for debugging.

- **--tracking nl:FILE**

  Prepare newline tracking information for debugging.

- **--tracking start:FILE**

  Prepare start of statement tracking information for debugging. Cannot be used with the -o option.

### Debug Options:

- **-p** *FILE*

  Dump debug info into *FILE*, or to stdout if *FILE* is set to '-'.\
   Must be used in combination with '-f *FILE*'.

- **-ds** *FILE* **--dump-steps** *FILE*

  Dump parsing info at various moments of the formatting process.\
   This creates a series of files named '*FILE*\_nnn.log', each\
   corresponding to a formatting step in uncrustify.\
   The file '*FILE*\_000.log' lists the formatting options in use.\
   Must be used in combination with '-f *FILE*'.

- **-L** *SEV*

  Set the log severity (see log\_levels.h)

- **-s**

  Show the log severity in the logs

- **--decode** *FLAG*

  Print *FLAG* as text and exit

## EXAMPLES

- Read a D file from stdin, output to stdout.

  cat foo.d \| uncrustify -q -c my.cfg -l d

- Process a file, output to stdout.

  uncrustify -c my.cfg -d foo.d

- Process a source tree, output to a different tree.

  find src -name "\*.\[ch\]" \> files.txt\
   uncrustify -c my.cfg -F files.txt --prefix out

- Process a source tree in‐place.

  uncrustify -c my.cfg --no-backup $(find src -name "\*.\[ch\]")

## NOTES

Use comments containing ' \*INDENT-OFF\*' and ' \*INDENT-ON\*' to disable processing of parts of the source file.

## AUTHOR

Written by Ben Gardner

## REPORTING BUGS

Use the issue tracker at \<http://sourceforge.net/projects/uncrustify\>

## COPYRIGHT

Copyright (C) 2006‐2014 Ben Gardner\
 Copyright (C) 2015, 2016 Guy Maurel

## LICENSE

GNU GPL version 2 or later \<http://gnu.org/licenses/gpl.html\>

This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.