EditorConfig Specification

This is version 0.15.1 of this specification.

Introduction (informative)

All content in this document is normative unless marked “(informative)”.

EditorConfig helps maintain consistent coding styles for multiple developers working on the same project across various editors and IDEs. The EditorConfig project consists of a file format for defining coding styles and a collection of text editor plugins that enable editors to read the file format and adhere to defined styles. EditorConfig files are easily readable and they work nicely with version control systems.

Terminology

Changed in version 0.15.1.

In EditorConfig:

  • “EditorConfig files” (usually named .editorconfig) include section(s) storing key-value pairs. EditorConfig files must conform to this specification.
  • “Cores” parse files conforming to this specification, and provide key-value pairs to plugins.
  • “Plugins” receive key-value pairs from cores and update an editor’s settings based on the key-value pairs.
  • “Editors” permit editing files, and use plugins to update settings for files being edited.

A conforming core or plugin must pass the tests in the core-tests repository or plugin-tests repository, respectively.

(informative) Some plugins include or bundle their own cores, and some rely on external cores. Some editors include or bundle plugin or core functionality. Editors, plugins, and cores may all come from different people. Those people may or may not have any direct interaction with the EditorConfig organization.

File Format

EditorConfig files are in an INI-like file format. In an EditorConfig file, all beginning whitespace on each line is considered irrelevant. Each line must be one of the following:

  • Blank: contains only whitespace characters.
  • Comment: starts with a ; or a #.
  • Section Header: starts with a [ and ends with a ].
    • May not use any non-whitespace characters outside of the surrounding brackets.
    • May contain any characters between the square brackets (e.g., [ and ] and even spaces and tabs are allowed).
    • Forward slashes (/) are used as path separators.
    • Backslashes (\\) are not allowed as path separators (even on Windows).
  • Key-Value Pair (or Pair): contains a key and a value, separated by an =.
    • Key: the part before the first = (trimmed of whitespace).
    • Value: The part after the first = (trimmed of whitespace).

Any line that is not one of the above is invalid.

EditorConfig files should be UTF-8 encoded, with LF or CRLF line separators.

No inline comments

Changed in version 0.15.0.

A ; or # anywhere other than at the beginning of a line does not start a comment, but is part of the text of that line. For example:

[*.txt]
foo = editorconfig ;)

gives variable foo the value editorconfig ;) in *.txt files, not the value editorconfig.

This specification does not define any “escaping” mechanism for ; or # characters.

Compatibility

The EditorConfig file format formerly allowed the use of ; and # after the beginning of the line to mark the rest of a line as comment. This led to confusion how to parse values containing those characters. Old EditorConfig parsers may still allow inline comments.

Parts of an EditorConfig file

The parts of an EditorConfig file are:

  • Preamble: the lines that precedes the first section. The preamble is optional and may contain key-value pairs, comments and blank lines.
  • Section Name: the string between the beginning [ and the ending ].
  • Section: the lines starting from a Section Header until the beginning of the next Section Header or the end of the file.

Glob Expressions

Section names in EditorConfig files are filepath globs, similar to the format accepted by .gitignore. They support pattern matching through Unix shell-style wildcards. These filepath globs recognize the following as special characters for wildcard matching:

Special Characters Matching
* any string of characters, except path separators (/)
** any string of characters
? any single character, except path separators (/)
[seq] any single character in seq
[!seq] any single character not in seq
{s1,s2,s3} any of the strings given (separated by commas, can be nested)
{num1..num2} any integer numbers between num1 and num2, where num1 and num2 can be either positive or negative

The backslash character (\\) can be used to escape a character so it is not interpreted as a special character.

Cores must accept section names with length up to and including 1024 characters. Beyond that, each implementation may choose to define its own upper limit or no explicit upper limit at all.

File Processing

When a filename is given to EditorConfig a search is performed in the directory of the given file and all parent directories for an EditorConfig file (named “.editorconfig” by default). Non-existing directories are treated as if they exist and are empty. All found EditorConfig files are searched for sections with section names matching the given filename. The search shall stop if an EditorConfig file is found with the root key set to true in the preamble or when reaching the root filesystem directory.

Files are read top to bottom and the most recent rules found take precedence. If multiple EditorConfig files have matching sections, the rules from the closer EditorConfig file are read last, so pairs in closer files take precedence.

Supported Pairs

Changed in version 0.15.1.

EditorConfig file sections contain key-value pairs separated by an equal sign (=). With the exception of the root key, all pairs MUST be located under a section to take effect.

  • EditorConfig cores shall accept and report all syntactically valid key-value pairs, even if the key is not defined in this specification.
  • EditorConfig plugins shall ignore unrecognized keys and invalid/unsupported values.

Here is the list of all keys defined by this version of this specification, and the supported values associated with them:

Key Supported values
indent_style Set to tab or space to use hard tabs or soft tabs respectively. The values are case insensitive.
indent_size Set to a whole number defining the number of columns used for each indentation level and the width of soft tabs (when supported). If this equals tab, the indent_size shall be set to the tab size, which should be tab_width (if specified); else, the tab size set by the editor. The values are case insensitive.
tab_width Set to a whole number defining the number of columns used to represent a tab character. This defaults to the value of indent_size and should not usually need to be specified.
end_of_line Set to lf, cr, or crlf to control how line breaks are represented. The values are case insensitive.
charset Set to latin1, utf-8, utf-8-bom, utf-16be or utf-16le to control the character set. Use of utf-8-bom is discouraged.
trim_trailing_whitespace Set to true to remove all whitespace characters preceding newline characters in the file and false to ensure it doesn’t.
insert_final_newline Set to true ensure file ends with a newline when saving and false to ensure it doesn’t.
root Must be specified in the preamble. Set to true to stop the .editorconfig file search on the current file. The value is case insensitive.

For any pair, a value of unset removes the effect of that pair, even if it has been set before. For example, add indent_size = unset to undefine the indent_size pair (and use editor defaults).

Pair keys are case insensitive. All keys are lowercased after parsing.

Cores must accept keys and values with lengths up to and including 1024 and 4096 characters respectively. Beyond that, each implementation may choose to define its own upper limits or no explicit upper limits at all.

Suggestions for Plugin Developers

TODO. For now please read the Plugin Guidelines on GitHub wiki.

Versioning

This section applies beginning with version 0.14.0 of this specification.

This specification has a version, tagged in the specification repository. Each specification version corresponds to the same version in the core-tests repository.

The version numbering of the specification follows Semantic Versioning 2.0.0 (“SemVer”). The version numbering of the core-tests repository also follows SemVer.

Each EditorConfig core, to pass the core tests, must process version numbers given with the -b switch, and must report version numbers when given -v or --version. The version numbers used for -b, -v, and --version are versions of this specification. For example, the Vimscript core might respond to -v with:

EditorConfig Vimscript core v1.0.0 - Specification Version 0.14.0

Cores, plugins, or editors supporting EditorConfig have their own version numbers. Those version numbers are independent of the version number of this specification.