It goes without saying that every good Linux desktop environment offers the ability to search your file system for files and folders. If your default desktop doesn’t — because this is Linux — you can always install an app to make searching your directory hierarchy a breeze.
But what about the command line? If you happen to frequently work in the command line or you administer GUI-less Linux servers, where do you turn when you need to locate a file? Fortunately, Linux has exactly what you need to locate the files in question, built right into the system.
The command in question is find. To make the understanding of this command even more enticing, once you know it, you can start working it into your Bash scripts. That’s not only convenience, that’s power.
How to use the find command
When I first glimpsed Linux, back in 1997, I didn’t quite understand how the find command worked; therefore, it never seemed to function as I expected. It seemed simple; issue the command find FILENAME(where FILENAME is the name of the file) and the command was supposed to locate the file and report back. Little did I know there was more to the command than that. Much more.
Find by name
Let’s break down that basic command to make it as clear as possible. The most simplistic structure of the find command should include a path for the file, an option, and the filename itself. You may be thinking, “If I know the path to the file, I’d already know where to find it!”. Well, the path for the file could be the root of your drive; so / would be a legitimate path. Entering that as your path would take find longer to process — because it has to start from scratch — but if you have no idea where the file is, you can start from there. In the name of efficiency, it is always best to have at least an idea where to start searching.
The next bit of the command is the option. As with most Linux commands, you have a number of available options. However, we are starting from the beginning, so let’s make it easy. Because we are attempting to find a file by name, we’ll use one of two options:
- name – case sensitive
- iname – case insensitive
Remember, Linux is very particular about case, so if you’re looking for a file named Linux.odt, the following command will return no results.
Find by type
What if you’re not so concerned with locating a file by name but would rather locate all files of a certain type? Some of the more common file descriptors are:
- f – regular file
- d – directory
- l – symbolic link
- c – character devices
- b – block devices
Now, suppose you want to locate all block devices (a file that refers to a device) on your system. With the help of the -type option, we can do that like.
Outputting results to a file
One really handy trick is to output the results of the search into a file. When you know the output might be extensive, or if you want to comb through the results later, this can be incredibly helpful. For this, we’ll use the same example as above and pipe the results into a file called conf_search. This new command would look like:
- find /etc -type f -name “*.conf” > conf_search
You will now have a file (conf_search) that contains all of the results from the find command issued.
Finding files by size
Now we get to a moment where the find command becomes incredibly helpful. I’ve had instances where desktops or servers have found their drives mysteriously filled. To quickly make space (or help locate the problem), you can use the find command to locate files of a certain size. Say, for instance, you want to go large and locate files that are over 1000MB. The find command can be issued, with the help of the -sizeoption, like so: