EAC Files

What is a .EAC file?

The extension ".EAC" is mostly utilized in EmEditor - the text editor for Windows by Emurasoft, Inc. in an EmEditor's auto-complete dictionary. These are word suggestions, phrases, or even codes which the editor can recommend when one works inside the file. Usually, one can find files like that in directories where settings are stored or backup copies of them; in exported EmEditor settings or language-specific list of suggestions, etc. There was not the registered type for MIME content-type for these files, and therefore the system treats them as unknown until they become associated manually with some application.

This file format does not belong to Exact Audio Copy software which usually opens files like ".WAV", ".LOG", and ".FLAC". Also it does not have any connection to Dolby Digital Plus or Enhanced Ac-3 audio streams (.EAC3, .EC3 or files in the container format like .MP4 and .MKV). The easiest way of identifying these files - open the file and look at its content through a simple text editor: if you see text, the file probably is from EmEditor.

How to open a .EAC file

Technical details

The EmEditor .EAC is text-based (as opposed to being binary) and doesn't have a static file signature defined. Since there is also no static header like for .zip or a byte sequence defining the file type like PK, you have to know it due to .eac suffix when the file comes from some user-defined export/import location on the hard disk.

Not having an official EmEditor standard and being dependent of many factors including the EmEditor version itself, its specific settings and how exactly that file comes from a certain auto-complete list makes two files generated at one instance and even using different versions non-comparing byte-wise (although still correct for use in EmEditor). .EAC is neither IANA nor MIME registered file types.

Encoding is probably the biggest technical aspect related to this particular file-type. Practically the .EAC format is normally stored in either UTF-8, with or without Byte-Order-Marker, and UTF-16 le for windows applications. Any weird representation of some accented Latin or CJK text or other mojibake symbols normally means opening this document with incorrect encoding (or even damaged file), not the bad file itself. Content is mostly some kind of the dictionary with entries (words, names and/or phrases used in auto-complete tool in the EmEditor).

File doesn't act as an archive container, Zip or DB type and therefore is processable without any specific treatment by regular text editor, diff tools, backup and version control soft etc. Also metadata are limited - usually there is nothing stored about path or time, but it belongs to a specific user and system anyway.

Usually file size varies depending of its particular application and ranges from several kilobytes to hundreds (for big symbol set of some computer language). While generic text/plain might work as type only if its content (and therefore exact encoding) is well-known beforehand, in all other situations application/octet-stream is a safer choice.

How to convert .EAC files

In fact, there are two options of conversions that are commonly requested, although other types are possible as well - .EAC to .txt and the other way around. The plain text conversion would allow reviewing and modifying content through various methods. Namely, the plain text copy could be printed, searched with Notepad++, Vim and other programs and stored in the system using source control, being the plain text itself. In order to retain dictionary entries after copying from EAC file, just do cp input.eac output.txtCopy command on the terminal. When some sort of sorting or removing duplicates are needed inside a spreadsheet, first convert the list to one-column .csv and then import the data to excel (for example), Calc in LibreOffice, etc.

Should there be a problem with the encoding, fix that before changing the actual format of the file. iconv allows converting a file in UTF-16LE format or a particular Windows code page. The conversion to the other type is possible with EmEditor when saving the file by “Save as” option. Such type of conversion will eliminate any of EmEditor's behaviour, including ordering, formatting and specific syntax in the case if the other format doesn’t know it.

It's noteworthy that renaming .EAC to .TXT and vice versa may not work after restoring the old extension of the file and moving it back to appropriate place.

Common problems and fixes

It's possible that opening a text file may prompt an error like “How do you want to open this file?” in case of .eac file associations aren't set correctly in Windows. In case it's sufficient to read the text only, install either free or professional editions of EmEditor, or in the Open with option in File Explorer choose notepad, notepad++ Sublime Text, Vim, kate, GNU Emacs. The most probable reason why entries have not been used by the autocompletion feature while opening such a file in EmEditor is the incorrect location, wrong assigned syntax/programming language, or incorrect file name.

In case of accented or non-English text that looks garbled, there must be problems with the encoding. You should try to reopen that file in UTF-8 or UTF-16LE encoding, or in any codepage encoding supported natively by EmEditor on windows (like e.g. code page 437). If your file has zero size, was cut off in case of program or network crash or due to synchronizer problem and it's impossible to recover its contents, all your suggestions will disappear until you'll recover the backup of the autocompletion file from EmEditor configuration backup, file history or cloud storage.

Extra suggestions/duplicate entries appear due to merging dictionaries. Sorting suggestions list, getting rid of duplicate lines (sort ->remove duplicate lines) is a solution. Suggested files that were modified in other editors may not take effect until EmEditor is restarted and new file format is re-read (configuration is cached internally). Most likely line ending differences won't produce extra suggestion files/dicts (as long as EmEditor understands all types), but strange-looking entries caused by NUL bytes or pasted binaries are possible. It is possible to edit those files that windows flagged as dangerous in Downloaded files properties dialog.

Security considerations

The EmEditor .EAC file is merely a plaintext database which does not execute as an executable binary but rather a macro file with embedded script-like elements. Entries are understood as words used in auto-completion and do not create code execution threats explicitly. Security threat in this case exists only on the level of editor itself and you need to make sure that EmEditor or whatever plain text editor you use is updated and running before opening any such files. Larger or non-normal EAC files could result in increased memory usage, degraded efficiency of lookups, denial of service in the editor environment or whatever other negative effect related to file content. List of words is actually a sensitive information as it could show your API name, clients' terminology and passwords stored there as word items and even some proprietary terms used in your projects, so when you decide to update EmEditor dictionaries you should make backups first before adding new untested one using a text editor.

History and versions

EmEditor represents Windows text editor from Emurasoft, which is in use since the nineties in the 20th century in processing large documents, text in the Unicode form and programming tasks. Extension .EAC was introduced as the part of the auto-completion feature, introduced in EmEditor along with configuration for auto-complete dictionaries and syntax based editing options. EmEditor Professional has continued the improvement in coding abilities during 2000s and 2010s by means of adding add-ons, code snippets, Unicode ability and large document support. First documentation in regard to auto completion for EmEditor mentions .EAC format in 2008 when the dictinary file was mentioned to belong to auto-complete feature.

Standards committee, such as IETF, ISO, ECMA or any other publicly available does not have any documentation related to standardization of .EAC format. Its functioning is established by means of EmEditor, rather than independent vendor-neutral documentation like .TXT or CSV. Actual practice shows the application exclusively on installations and archives of EmEditor user configurations. Users of EmEditor don’t open .EAC files as standalone but operate them through interface of EmEditor.

Related formats

The plain .TXT is the one that comes the most neutral next to the .EAC completion list. You’ll get an easier file for your transfers with such tools as cp, but no EmEditor names as well as no automated support. The .CSV file works well where you need the sorting options, tagging options, and duplicates deletion using spreadsheets, but where there are comma usage, quotations rules, fields etc. The .JSON file suits for the modern editor extensions and web applications, since it allows storing arrays, objects, it possesses special syntax and rules. The Visual Studio Code relies on .code-snippets JSON files, Sublime Text uses .sublime-completions JSON files, where there could be used such features as placeholders or trigger/content. In turn, Vim uses such extensions or file types as .dic, .txt, and filetype. In turn, the Office AutoCorrect files as well as .DIC are devoted to spelling checking. In case your file is binary audio check whether it's .EAC, .EAC3, or .EC3 files with MediaInfo or ffprobe.