---
name: "cppi"
section: "1"
platform: "linux"
package: "cppi"
version: "1.18-3"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/cppi"
---

# cppi(1)

indent the C preprocessor directives in FILE to reflect their nesting

## NAME

cppi - indent the C preprocessor directives in FILE to reflect their nesting

## SYNOPSIS

**cppi** \[*FILE*\]\
 **cppi** *-c* \[*OPTION*\] \[*FILE*\]...

## DESCRIPTION

Indent the C preprocessor directives in FILE to reflect their nesting and ensure that there is exactly one space character between each #if, #elif, #define directive and the following token, and write the result to standard output.  The number of spaces between the \`#' and the following directive must correspond to the level of nesting of that directive. With no FILE, or when FILE is -, read standard input.

- **-a**, **--ansi**

  when checking, fail if text follows #else or #endif

- **-c**, **--check**

  set exit code, but don't produce any output

- **-l**, **--list-files-only**

  don't generate diagnostics about indentation; print to stdout only the names of files that are not properly indented

- **-m**, **--max-string-length**=*LENGTH*

  fail if there is a double-quoted string longer than LENGTH;  if LENGTH is 0 (the default), then there is no limit

- **--help**

  display this help and exit

- **--version**

  output version information and exit

With the **-c** option, don't write to stdout.  Instead, check the indentation of the specified files giving diagnostics for preprocessor lines that aren't properly indented or are otherwise invalid.

Note that **--ansi** without **--check** does not correct the problem of non-ANSI text following #else and #endif directives.

### The exit code will be one of these:

- 0

  all directives properly indented

- 1

  some cpp directive(s) improperly indented, or text follows #else/#endif (enabled with **--check** **--ansi**), or a double-quoted string is longer than the specified maximum

- 2

  \#if/#endif mismatch, EOF in comment or string

- 3

  file (e.g. open/read/write) error

A pragma directive may have its \`#' indented.

## AUTHOR

Written by Jim Meyering.

## REPORTING BUGS

Report bugs to \<bug-cppi@gnu.org\>.

## COPYRIGHT

Copyright © 2013 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later \<http://gnu.org/licenses/gpl.html\>.\
 This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.

## SEE ALSO

The full documentation for **cppi** is maintained as a Texinfo manual.  If the **info** and **cppi** programs are properly installed at your site, the command

-

  **info cppi**

should give you access to the complete manual.