The linux find command

01.20.10

Using the find command to find and move files

Today I’d like to discuss one of my favorite shell commands: find.
find is awesome.  It locates files on your unix/linux system by using options and criteria.

Many of us are familiar with using the Microsoft Windows “Search Tool” in XP to Find Files or Folders, files by date, etc.  Finding a file this way involves populating text fields, drop-down menus, and (possibly) date-range selectors to find the files you’re looking for.

In unix and linux, the find command is used like this:

find [directory to search] [options] [actions]

Here’s a find command example.  Let’s say we want to find .mp3 files within your “Music” folder (/home/yourName/Music).  For this example, let’s pretend that you have the following files: song1.mp3, song1.wav, song2.mp3, song2.wav, song3.mp3, and song3.wav.

To find files in the Music directory, the command is: [don’t type the dollar sign- it’s the prompt, start typing at the word “find”.]

$ find Music/ -type f [press ENTER]
Music/song1.mp3
Music/song1.wav
Music/song2.mp3
Music/song2.wav
Music/song3.mp3
Music/song3.wav

We used the “-type f” option to find a regular file and not a directory.  The output (above) shows that we have media files (mp3 and wav) in the Music folder.  Remember we’re not interested in listing files so much as performing a ‘find’ on them.

On a Linux system you can use a GUI program to find files, but you can find them faster using the find command.  With its many options, find’s power is in its flexibility.  Flexibility to do what??? Finding files is finding files, right? Yes, I suppose so.

But what if you wanted to perform an action on files that you find? In Windows you’d have to first find them, navigate to them, and then (possibly) perform actions on them one file at a time.  While the steps are few, they can be manual and tedious, thus begging for a shortcut.

Let’s take our example a step further.  Let’s filter the command to only find ‘mp3’ files.  We’ll add the “-name” option to search wildcard patterns for files ending in mp3.

$ find Music/ -type f -name "*mp3"
Music/song1.mp3
Music/song2.mp3
Music/song3.mp3

If you wanted to find only the .wav files, then you’d change *mp3 to *wav.  Now let’s use find to move files to another folder.  For the sake of neatness, let’s create 2 sub-folders (also known as sub-directories) to hold mp3 files and a separate sub-folder for wav files.

To create a new directory use mkdir [folderPath].  If you do not specify a folder path, the shell creates the directory within the current working folder.  More on “current working folder” later.  For now, let’s assume that you’re in the “home/yourName” folder.

Creating folders “Music/mp3” and “Music/wav” requires 2 identical commands.  However, you can create 2 sub-directories in the “Music” folder with the command below.

mkdir Music/{mp3,wav}

Brackets tell the shell to expect a sequence of characters.  The comma separates each new directory.  This is the same as issuing mkdir Music/mp3 and mkdir Music/wav.

With the sub-folders created, we have a neater storage arrangement for our music files.  But we’re not done yet.  Remember that our “Music” folder currently stores both mp3 and wav files.  Let’s move each type into their respective sub-directory.  To make this happen we add an action onto our command known as “-exec” (followed by the “command terminator” \;) and the mv command to move the files as seen in the example below:

mv fileOldLocation fileNewLocation

Note: mv also renames files and can overwrite them—so use caution because mv actions cannot be undone.  For safety, use mv -i which is interactive in the event of a possible naming conflict or unintentional overwrite—it may save you anguish.

We then add brackets {}, BUT brackets behave differently in this context.  When brackets are part of -exec they represent each found file.  Also, when moving a file to another directory, put the trailing slash / on the target directory name.

To move the mp3 files from directory level “Music” to “Music/mp3” issue this command:

$ find Music/ -type f -name "*mp3" -exec mv -i {} Music/mp3/ \;

Since there weren’t any files in Music/mp3 we didn’t get any warnings from mv -i
Result: mp3 files moved from /home/yourName/Music to /home/yourName/Music/mp3/

To check it, you can use the ls command in the shell to “list” files in a given directory

$ ls Music/mp3/
song1.mp3  song2.mp3  song3.mp3

To move the wav files from directory level “Music” to “Music/wav” issue this command:

$ find Music/ -type f -name "*wav" -exec mv -i {} Music/wav/ \;
$ ls Music/wav/
 song1.wav  song2.wav  song3.wav

Summary

  • find (and its options) allow you to find files and perform actions on the found items
  • mkdir allows you to create new directories
  • ls lists files (and directories, subdirectories) within folder(s)
  • mv moves or renames files

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One Response to “The linux find command”

  1. Website Development says on :

    terrific article! thanx alot!

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