Command to Find the Type of Files Without Extensions

Introducing commands that can be used in the Linux PC or server Bash command line to find out what type of files without extensions are.

Background

SQLite database files often have no extension. The other day, I had the opportunity to work with the History file in the Google\Chrome\User Data\Default folder, and I wondered, “I know this file is SQLite, but how can I tell it’s an SQLite file when it has no extension?”

If you can identify that it’s an SQLite file, you can easily open it with viewer software like DB Browser for SQLite. However, if there’s no extension, you don’t know what kind of file it is, and you hesitate to open it, right?

Command Introduction

Linux has a convenient command that tells you what kind of file it is for files without extensions. That’s the file command.

Here are some specific examples.

Example 1: Identifying the History File

$ ls History
16888498605221144 -rwxrwxrwx 1 user user 27000832 Mar 24 09:45 History

$ file History
History: SQLite 3.x database

In this example, you can see that the History file is an SQLite 3.x database file.

Example 2: Identifying the Bookmarks File

$ ls Bookmarks
11540474047715538 -rwxrwxrwx 1 user user 2057085 Mar 24 09:25 Bookmarks

$ wc Bookmarks
  39250   97271 2057085 Bookmarks

$ file Bookmarks
Bookmarks: UTF-8 Unicode text, with very long lines, with CRLF line terminators

$ head Bookmarks
{
   "checksum": "48fd3028..e870260",
   "roots": {
      "bookmark_bar": {
         "children": [ {
            "children": [ {
               "children": [ {
                  "date_added": "13132775602996953",
                  "id": "2782",

In this example, you can see that the Bookmarks file is UTF-8 Unicode text.

Summary

To identify the type of files without extensions, Linux’s file command is very useful. Using this command makes it easy to open files with appropriate software based on the file’s content. Please try using it.