AutoFenc

A Vim plugin that tries to automatically detect and set file encoding when opening a file.

Description

This Vim plugin tries to automatically detect and set file encoding when opening a file. It does this in several possible ways, depending on the configuration.

The following methods are implemented. When a method fails, the plugin tries the next one.

detection of BOM (byte-order-mark) at the beginning of the file, only for some multibyte encodings
HTML way of encoding detection (via the <meta> tag), only for HTML-based file types
XML way of encoding detection (via the <?xml ... ?> declaration), only for XML-based file types
CSS way of encoding detection (via @charset 'at-rule'), only for CSS files
checks whether the encoding is specified in a comment (like # Encoding: latin2), for all file types
tries to detect the encoding via the specified external program (the default one is enca), for all file types

If the autodetection fails, it is up to Vim and your configuration to set the encoding.

Installation

The recommended way of installing this plugin is by using Pathogen.

If you cannot use Pathogen or you want to install this plugin manually, just put the plugin/AutoFenc.vim file into your $HOME/.vim/plugin directory (Linux-like systems) or %UserProfile%\vimfiles\plugin folder (Windows systems).

Configuration Options

The plugin has the following configuration options. You can set them in your $HOME/.vimrc file.

g:autofenc_enable (0 or 1, default 1)

Enables/disables this plugin.
g:autofenc_emit_messages (0 or 1, default 0)

Emits messages about the detected/used encoding or warnings upon opening a file.
g:autofenc_max_file_size (number >= 0, default 10485760)

If the size of a file is higher than this value (in bytes), then the autodetection will not be performed.
g:autofenc_disable_for_files_matching (regular expression, see the settings in plugin/AutoFenc.vim)

If the file (with complete path) matches this regular expression, then the autodetection will not be performed. It is by default set to disable autodetection for non-local files (e.g. accessed via ftp or scp) because the script cannot handle some kind of autodetection for these files. The regular expression is matched case-sensitively.
g:autofenc_disable_for_file_types (list of strings, default [])

If the file type matches some of the filetypes specified in this list, then the autodetection will not be performed. The comparison is done case-sensitively.
g:autofenc_autodetect_bom (0 or 1, default 0 if ucs-bom is in fileencodings, 1 otherwise)

Enables/disables detection of encoding by BOM.
g:autofenc_autodetect_html (0 or 1, default 1)

Enables/disables detection of encoding for HTML-based documents.
g:autofenc_autodetect_html_filetypes (regular expression, see the settings in plugin/AutoFenc.vim)

Regular expression for all supported HTML file types.
g:autofenc_autodetect_xml (0 or 1, default 1)

Enables/disables detection of encoding for XML-based documents.
g:autofenc_autodetect_xml_filetypes (regular expression, see the settings in plugin/AutoFenc.vim)

Regular expression for all supported XML file types.
g:autofenc_autodetect_css (0 or 1, default 1)

Enables/disables detection of encoding for CSS documents.
g:autofenc_autodetect_css_filetypes (regular expression, see the settings in plugin/AutoFenc.vim)

Regular expression for all supported CSS file types.
g:autofenc_autodetect_comment (0 or 1, default 1)

Enables/disables detection of encoding in comments.
g:autofenc_autodetect_commentexpr (regular expression, see the settings in plugin/AutoFenc.vim)

Pattern for detection of encodings specified in a comment.
g:autofenc_autodetect_num_of_lines (number >= 0, default 5)

How many lines from the beginning and from the end of the file should be searched for the possible encoding declaration.
g:autofenc_autodetect_ext_prog (0 or 1, default 1)

Enables/disables detection of encoding via an external program (see additional settings below).
g:autofenc_ext_prog_path (string, default 'enca')

Path to the external program. It can be either a relative or absolute path. The external program can take any number of arguments, but the last one has to be a path to the file for which the encoding is to be detected (it will be supplied by this plugin). The output of the program has to be the name of the encoding in which the file is saved (a string on a single line).
g:autofenc_ext_prog_args (string, default '-i')

Additional program arguments (can be none, i.e. '').
g:autofenc_ext_prog_unknown_fenc (string, default '???')

If the output of the external program is this string, then it means that the file encoding was not detected successfully. The string has to be case-sensitive.
g:autofenc_enc_blacklist (regular expression, default '')

If the detected encoding matches this regular expression, it will be ignored.

Notes

This script is by all means NOT perfect, but it works for me and suits my needs very well, so it might be also useful for you. Your feedback, opinion, suggestions, bug reports, patches, simply anything you have to say is welcomed!

There are similar plugins to this one, so if you do not like this one, you can test these:

FencView.vim: Mainly supports detection of encodings for asian languages.
MultiEnc.vim: Obsolete, merged with the previous one.
charset.vim: Not very complete/correct and last update in 2002.
Detect encoding from the charset specified in HTML files: Same basic ideas but only for HTML files.

Let me know if there are others and I will add them here.

License

Distributed under GNU GPLv2:

This program is free software: you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the Free
Software Foundation, either version 2 of the License, or (at your option)
any later version.

This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
more details.

You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.