# cflow-mode

> major mode for visiting flow charts in GNU Emacs

**Wikidata**: [Q110315224](https://www.wikidata.org/wiki/Q110315224)  
**Source**: https://4ort.xyz/entity/cflow-mode

## Summary
cflow-mode is a major mode for the GNU Emacs text editor designed for visiting and navigating flow charts. Written in Emacs Lisp by Sergey Poznyakoff, it serves as an extension for the GNU cflow utility. The software is free, cross-platform, and has been maintained by its creator since 1994.

## Key Facts
- **Creator:** Sergey Poznyakoff (programmer and GNU maintainer)
- **Inception:** 1994
- **Primary Use:** Visiting flow charts within GNU Emacs; functions as an Emacs mode for GNU cflow
- **Platform:** Cross-platform (requires GNU Emacs)
- **Programming Language:** Emacs Lisp
- **Software Class:** Free software; Emacs extension; software library
- **Part Of:** GNU cflow package
- **Aliases:** cflow-mode.el, cflow.el
- **Source Repository:** `https://git.savannah.gnu.org/cgit/cflow.git/tree/elisp/cflow-mode.el`
- **Package ID:** NetBSD package `devel/cflow-mode`

## FAQs
### Q: What is the purpose of cflow-mode?
A: cflow-mode provides a dedicated environment within GNU Emacs for viewing and interacting with flow charts. It integrates with the GNU cflow utility to help users analyze program control flow.

### Q: Who created and maintains cflow-mode?
A: The software was created by Sergey Poznyakoff in 1994. He continues to maintain the project as the copyright holder.

### Q: Is cflow-mode free to use?
A: Yes, cflow-mode is classified as free software and is part of the free software movement. It is distributed under terms that allow users to run, study, and modify the software.

## Why It Matters
cflow-mode plays a specific but important role in the GNU ecosystem by bridging the gap between the GNU cflow utility and the GNU Emacs text editor. While many developers rely on separate graphical tools for static analysis, cflow-mode allows for the inspection of flow charts directly within the editing environment. This integration streamlines the workflow for programmers who use Emacs, enabling them to analyze the control flow of C programs without context switching.

As a component of the broader GNU cflow project, it represents the modular philosophy of Unix-like systems, where distinct tools (the analyzer and the editor) work together through standardized modes. Its longevity—maintained continuously since 1994—highlights its utility as a lightweight, text-based solution for code visualization.

## Notable For
- **Longevity:** Maintained continuously since 1994 by the original author.
- **Integration:** Acts as the official Emacs interface for the GNU cflow static analysis tool.
- **Portability:** Operates on any platform supported by GNU Emacs.
- **Licensing:** Distributed as free software, adhering to the principles of the free software movement.

## Body
### Development and History
cflow-mode was created in 1994 by Sergey Poznyakoff, a programmer and GNU maintainer. It is written entirely in Emacs Lisp, the dialect of Lisp utilized by GNU Emacs. The project is part of the official GNU cflow software package.

### Technical Functionality
The primary function of cflow-mode is to provide a "major mode" for visiting flow charts. In the context of GNU Emacs, a major mode is the main functionality of a buffer, customizing the editor's behavior for a specific type of content. By using cflow-mode, users can view and navigate the output generated by the GNU cflow utility, which analyzes the control flow of C source code.

### Distribution and Availability
The source code for the extension is available in the official GNU cflow git repository (`elisp/cflow-mode.el`). It is licensed as free software (specific license referenced as Q27016754 in structured data) and is classified as copyrighted work held by Sergey Poznyakoff. The tool is cross-platform, functioning on any operating system where GNU Emacs is installed, and is also available via the NetBSD package system as `devel/cflow-mode`.

## Schema Markup
```json
{
  "@context": "https://schema.org",
  "@type": "SoftwareApplication",
  "name": "cflow-mode",
  "description": "Major mode for visiting flow charts in GNU Emacs",
  "alternateName": ["cflow-mode.el", "cflow.el"],
  "author": {
    "@type": "Person",
    "name": "Sergey Poznyakoff"
  },
  "dateCreated": "1994",
  "programmingLanguage": "Emacs Lisp",
  "operatingSystem": "Cross-platform",
  "applicationCategory": "DeveloperApplication",
  "isPartOf": {
    "@type": "SoftwareApplication",
    "name": "GNU cflow"
  },
  "codeRepository": "https://git.savannah.gnu.org/cgit/cflow.git/tree/elisp/cflow-mode.el"
}

## References

1. [Source](https://git.savannah.gnu.org/cgit/cflow.git/tree/elisp/cflow-mode.el)
2. Free Software Directory